Minutes of the February 11, 2014 weekly meeting

• Calorimeter in the test lab: report by Kijun
  The work was performed by Hashir, Lee and Kiun with some help from Julie.
  • Since the last meeting, all blocks of the calo have been tested using cosmic rays. The blocks were powered one by one. All but 5 blocks/PMT/ampli were found to be operational. For the 5 "bad" ones, the HV and signal cables were interchanged with neighboring blocks (up to the cables between the distribution boards and the bases). The problems are with the pmt and/or ampli. These 5 blocks will have to be pulled out of the assembly for further investigations.
  • Preparing to work on the paddle for the cosmic paddle. The screws that stuck out in the space where the cosmics paddle will go, have been replaced.
  • This week will be spend establishing the trigger, cabling the ARS and setting up the DAQ.
• Trigger: report by Norman
  • Norman confirmed that opening the front panel in order to cool the modules did not make the module work. (i.e. setting the front panel back did not break the module)
  • Coda has been installed on the laptop Norman uses in the electronic lab. It is almost functional but for using the correct VME list that allow the full reading of the trigger header.
  • Plan for next week:
    • Implement run with block transfer
    • Investigate the source of the zeros in the ADC readout. Norman will put together a list of tests he plans before performing them.
    • Norman has some questions out to Magali (regarding some LED being red and the zeros in the read out). Hoping for answers very soon.
• LED : report by Marco
  • will be at JLab next week
  • got some feedback from Magali about the LED operation. As a result went on building a lemo to rub ban cable necessary

Present: J. Roche, C. Hyde, F. Sabatie, M. Defurme, H. Albataineh, A. Camsonne, C. Munoz Camacho.
Please send comments and corrections to Julie.

• 12 GeV experiment
  • Experiment readiness review form: to submit to Thia asap. The only info missing are the one from "Utilities requirements". These info should come from JLab as our experiment is standard. Alex Camsonne is going to gather the info asap.
  • Magali reports that CODA is working fine now in Clermont and she is able to read data in a real-life setting configuration. She will soon start working on the new version of the trigger supervisor.
  • Alex Camsonne will start putting stuff in the TED space soon before people start to squat it. Things we can move: blocks, shelves, .. Carlos proposes that the DAQ be setup there but Alex C. says he would prefer to do test on speed transfer in the HRS to study the dead-time, the DAQ would be installed in the TED when we test the calorimeter (with cosmics).
  • Al. Gavalya wants to discuss a new system for the long cables. Charles is on top of this
• DVCS2: Physics progresses
  • Maxime is in the middle of things for the Cerenkov efficiency and the dead-time correction.
  • Orsay has been working on the multi-track using the method presented by O. Hansen. Again work is in progress.
  • Geant 4 simulation (by Raphael): now good agreement between Geant4 and the old Geant3 (within statistical simulation).

Present: J. Roche, C. Hyde, C. Munoz Camacho, A. Camsonne, H. Albataineh, V. Sulkosky, M. Defurme, F. Sabatie, anyon else (sorry I did not hear you)
Please send comments and corrections to Julie.

JR joins the meeting a few minutes late.

• Charles contribution to the Hall A : to read before Friday. https://hallaweb.jlab.org/dvcslog/DVCS2/159
• Maxime's DIS results: Multitrack corrections. https://hallaweb.jlab.org/dvcslog/DVCS2/160 Event with more than two track in the VDC exhibit almost energy deposited in the pion rejector, some event with only two tracks show an "electron"peak in the pion rejector. If one supposes that the multitrack events are "pions", then the correction as implemented so far over estimates the cross-section (and the correction is kinematic dependent). Question: are all multi-tracks really pion? Why? The next step is probably to check add some cuts in the focal plane. Also some questions at the end of this discussion concerning boiling correction and beam trip: Julie will dig out her notes thought Carlos remembers that the conclusions at the time where that these were not a problem.
• Carlos: Malek timing corrections (run by run) are now implemented in the standard analyzer. Malek's elog: https://hallaweb.jlab.org/dvcslog/DVCS2/155 Carlos will document in the elog how to call the new function.
• 12 GeV preparation: Magali is having trouble with starting coda: Alex will try to look at that remotely.
• No meeting next week as some of us will be at the Hall A collaboration meeting. <\ul>

Present: R. Paremuzyan, J. Roche, C. Hyde, C. Munoz Camacho, A. Camsonne.
Please send comments and corrections to Julie.

• 12 GeV preparation
  • [joining now] From Carlos: there will be two PMT shipments back from France : one for high efficiency (16 PMTS?) and another ones for "regular" PMTS. The PMTS will be shipped in January from France.
  • Alex 's trip at Clermont: The installation of CODA has been successful. The end of run routine is crashing the system maybe half of the time ; this is more an annoyance then a big issue. Magali is now working with a "realistic" setting, she has been sending some run to Carlos: some parameters still need to be tweaked (for example, the full ARS window is not showing up).
  • From Charles commenting on shielding design. See entry: https://hallaweb.jlab.org/dvcslog/12+GeV/120 A. Gavalya is proposing two new shielding pieces. One that is stuck along the beamline at the exit of the scattering chamber and another one that is stuck along the calorimeter box on the beamline side. For the first one on the beam pipe itself: still need to decide on its height. For the second one: it might results from mis-communication, it is unclear we need it and it will probably make the motion of the dark box a bit more complicated. [JR missing some discussion here :( ] The people from Orsay will try to see the impact of these shielding with Geant 4.
  • The group have a meeting with Tanja Horn about the neutral facility in Hall C. Fill the Doodle at : http://www.doodle.com/usgvy739c6nc4d6f
• 6 GeV analysis
  • Work being done at Orsay: pion calibration a la Malek, still setting up routines for pi zero subtraction. Geant 4 trying to extract DVCS cross section from the previous experiment: still work in progress.
  • Maxime and the extraction of DIS cross-sections: (1) looking at improving the multitracks corrections. (2) Charles will ping Thia for a new parametrization of the PDF. (3)Found the source of the discrepancy between the simulation and the data (angle theta- vertical): this mismatch only exists when the collimator was in. One issue is that there is no automatic reading for the position of the collimator, Alex will double check this.(4) Deadtime corrections: two different ways to compute them that gives different results. The discrepancy could be due by the amount of beam trip during the run. Maxime is checking this.
• A. Camsonne to submit his DOE early career proposal today at 5pm. Good luck !

Present: C. Munoz Camacho, J. Roche, A. Camsonne, P. Bertin, H. Albataineh, C. Hyde

• 6 GeV analysis:
  • Wave form analysis file have been produced. Malek is rechecking the timing (that was the reason for which the data were replayed). Ntuple have been produced, one and two clusters ntuple were produced.
  • Next step: improve the energy calibration of the calorimeter: Camille is doing that. Alejandro is working on the pi0 subtraction (use the two photon event to randomize the decay to non equal pions).
• 12 GeV preparation
  • Alex was supposed to meet Robin tomorrow. Alex asked question about shielding (Note I really had trouble hearing this part...)
  • Bogdan asked if it would be ok to only used S0 instead of S0+S1. Alex cannot find a reason not to agree. Bogdan also want to change the cerenkov to a shorter one in order to accomodate the FPP. Bogdan also want to make a shower trigger (the idea is to get more pion rejection) but it is unclear if he is wants to use it. Charles asked how much modifications would be need to accomodate the long cerenkov: Alex will ask the designer. For memory last time we used (S0+S1)+ long CerenkoV as the trigger.
  • Julie has some money left on her NSF grant, and she has to commit the money before December. Charles and Carlos suggest to look at PMTs. If anyone has other ideas, the order will not go in for another month at least.

• Hall A collaboration:
  • Meeting: Orsay to give the analysis update talk (15min), Charles to give the 12 GeV (20 min), Alex to give his DDVCS presentation (20 min). Talks will be on Tuesday December 12, 11am to noon (TBC).
  • Annual report: It needs to be written. Due mid december basically at the same time than the meeting. JR add-on: S. Riordan (chair of the CC) has proposed the report be posted to arxiv.
• DVCS collaboration meeting:
  • Tanja Horn has put together an agenda for the Sunday meeting (4h total).
  • Carlos asks for new comments about the agenda. What about the phi proposal? Charles says the phi idea was actually to use the SBS to detect the two decay pion (opposite charge). The Hall C setup would not be able to do that. For the Hall C setup maybe a eta decay would work better. Carlos remind us that Tanja's goal is to add DVCS to her suite of pion experiment to get her program accepted by the PAC so there might not be a point in looking at "exotic" new channel. Charles states that we should make sure to explore the possibility to use our calorimeter in Hall C.
• DVCS analysis:
  • Carlos: additional analysis pass (see last week minutes) is over. Malek will check that the timing is ok and perform some pi0 calibration. This might take a while, maybe a month or two.
  • Simulation: the simulation is running, the simulation is producing an ntuple. Right now, the simulation is used for counting rate estimates for example comparing to the 12 GeV proposal. The next set is to reproduce the result of the first experiments (keep in mind the setup was slightly different).
  • Charles ask about the status of the file at JLab? All the files are at JLab. The new files are in mss: /mss/home/munoz/DVCS2/alex3rdprod/ The structure of the files is still a bit complicated: they are still full Ttree structure (not ntuple) with many info for each block. Here is a macro that will transform them into an easier ntuple: /work/halla/dvcs/disk4/carlos/clustering.C, you need to run the following macro first to get the good environment: source /work/halla/dvcs/disk1/carlos/64bits/setup.sh

Present: P. Bertin, A. Camsonne, M. Mazouz, C. Munoz-Camacho, J. Roche

• 6 GeV analysis:
  Alejandro is back. He re-started the replay of the runs. In the last replay, Malek had found: (i) some runs had event outside the analysis window - this was a small portion of the runs, (ii) some splits were analyzed without timing corrections, while other splits from the same run were replayed with the correction. It was unclear why this happened so the whole statistic is being replayed. The replay is going fast, should be done by the end of the week. Then Malek (and Alejandro?) will have to check the timing again. Malek has made an entry with an how-to do the corrections (see elog https://hallaweb.jlab.org/dvcslog/DVCS2/150)
• November collaboration meeting
  
  • check again the agenda and talk to Carlos if you want something changed: https://indico.in2p3.fr/conferenceDisplay.py?confId=7052
  • Malek will present not only timing correction for the calo but also the energy calibration using his pi0 method. Malek's student got a grant for a PhD, she has already started to work with him on calorimeter optimization (Kine II-low). She will most likely take part to the meeting.
  • Alexandre will invite Shalev Gilad to the meeting to represent Gmp.
  • Alexandre will give a seminar at Clermont about the 12 GeV upgrade on Friday November 16.
  • Alexandre suggest to maybe had a DDVS presentation/discussion of his DOE proposal (see https://hallaweb.jlab.org/dvcslog/12+GeV/109)
• 12 GeV preparation:
  
  • Carlos will send the PMT back shortly to JLab. Alexandre suggests to wait for him to secure the TED space. Right now the blocks are in the hall, they were not flooded as flooding was minimal in Hall A (only 5cm)
  • Thia asked if the calorimeter can be moved once assembled. Carlos says that it will not be a big time saver has a survey will be needed for each move. JR: We did not talk about this: could this be way to protect the blocs of radiation damage if Gmp wants to do some high current runs. We might not be able to stall them for ever on this.
  • Trigger: Alexandre has started to look at installing a standalone version of coda at Clermont. He seems to him that he will be able to do that during his November stay (following the collaboration meeting). Having someone in France to help would be good, maybe a student? We talk about a possible student but decide to check with his adviser first. JR: who is going to do that? Also there was some comment about Magali stating that there is no change to the trigger program but I don't know why this is important here
• Hall A collaboration meeting (December 10 &11)
  • at this time DVCS is given an hour and 3 talks: 6 GeV update, 12 GeV presentation, DDVCS presentation. We have some flexibility on the organization within that hour.
  • DDVCS proposal by Alexandre (see https://hallaweb.jlab.org/dvcslog/12+GeV/109): The pre-proposal was accepted, the full proposal is due November 29 (?). Alex will use a simulation of the GEM by Seamus Riordan, he also has a version of the VGG code for DDVCS.
  • the Hall A analysis workshop will take place on December 12, it is organized by Ole Hansen.

Edited: 09/25/12, 03:55 

 
    We went over Charles' slides for the GMp collaboration meeting, as well as those available from Al Gavalya and Bogdan. Slides for this meeting are in the Hall A wiki at :

https://hallaweb.jlab.org/wiki/index.php/GMp_collab_meeting_Sept_2012

Charles posted minutes at :

https://hallaweb.jlab.org/dvcslog/12+GeV/114

• 12GeV preparation
  • We want 15 cm loop (GMP wants 20cm). The other targets Alex listed on ELOG entry 108 are ok.
  • LHRS repair with Bogdan: both Charles and Julie were contacted by Bodgan with a request to help out in the upgrade/refurbishing of the LHRS. The work described by Bogdan is upgrade of the electronic of the VDC and repair of the Cerenkov. Both Charles and Julie said they will try to provide a student (for Julie at the earliest in summer 2013).
  • Charles plans to attend the GMP coll meet. The meeting in Monday afternoon Sept 17, 2-6 pm. Charles plans to present a run plan.
• Miscellanous:
  • 6 GeV analysis: Alejandro is still in vacation: no progress since last week.
  • Alexandre is putting together a DOE early career proposal. He is proposing to build a GEM based vertex detector to try to measure Double DVCS. See: Elog 109
  • The hall A CC met last week. The Winter Hall A meeting is scheduled for Monday December 10 and Tuesday December 11 with a software workshop on Saturday December 8. Dates need to be comfirmed.
  • Pion paper: Charles and Eric still need to talk.

• Pi0 paper
  • Charles comment on Elog Results 186 Charles studied Eric's code: the asymmetries values extracted are consistant with the definition given in the paper. It seems a factor of two was forgotten in both the extraction of the asymmetry and the fact that the luminosity decreases roughly by two when considering individual helicity. So the paper seems to be A-ok. There is still an open questions about the update that is in preparation: a factor of 2Pi is floating around in the extraction of the cross-sections (see Charles' note). To go further, Charles will make sure that Eric is using the appropriate luminosity, and will check some numbers (cross-sections versus asymmetries) numerically.
  • Eric will be out of the office (maybe back in France) for two months. Before leaving, he posted the update to the paper (actual cross section as a function of phi instead of just the parameter of the fit) to ELOG.
• 12 GeV preparation: no news from Al Gavalya. The GMP collaboration will have a meeting on Sept 24, 2-6pm (TBC), Vince is actually in hcarge of the agenda. Charles will try to be present and make a plea against the "symbiotic" running in favor of a split running, or at least try to explain what are our constraints if this running mode happens.
• Producing the ntuple: no progress there (Alejandro is in Spain). Still checking timing corrections that Malek found to be not right.
• Simulation: implemented cross-section model into it. The model is by P. Kroll based on pion data. The main advantage is that the model is fast (compared to VGG for example).
• Check out the draft agenda of the November collaboration meeting. Feel free to suggest modifications and/or additions. The Sunday Hall C should be going on: participants are A-ok with he meeting, the logistic still needs to be worked out.

• 12 GeV preparation: We discuss the schedule that Thia sent us by email last week. Basically running March-June 2014 and then September-December 2014, symbiotically with GMp. From what we know no slides or memo have been posted anywhere, Alex will keep us posted as things develop. Here are some questions we have:
  • The schedule Thia sent by email is not what she discussed with Charles and Alex. Charles and Alex will have to talk to Thia again, maybe Tuesday Aug 28. What does symbiotically means? When will GMp runs the small angle part of their program?
  • There is no update with the scattering chamber: Al Gavalya has all the info he needs to try to work this out though. In plus of new windows and large exit mouth for the scattering chamber, a new stand is being designed. One needs to check that the new stand allow us to reach the small angle. Are all infrastructure modification rising the price tag of our experiment? Keep in mind we are not asking for the modifications, they are only made to accomodate Gmp.
  • Space issue: a space in the TED was proposed by Thia. It looks like a decent space and it is smaller than what we expected. Charles remind us of the space at ODU and also the availability of Tom (a tech).
  • Julie discussed her rough plans for her new NSF proposal: P. King will get involved, she plans to be at JLab for the whole 2014 and she plans to be on leave from the university from Jan. 2014 to Summer 2015.
• Pi0 paper: Eric and Carlos believe that what was published is 2 sigma_TL' That is ((N+ - N-)/(N+ + N-)). Charles wants to cross-check this himself. Charles thinks that because N+ is produced with half of the total luminosity, but the denominator of the ratio is the full luminosity the 1/2 factor is there be default. Charles will circulate a note that explains his reasoning.
• DVCS2: Orsay is following on the oddities Malek found during his timing correction study. Malek correction will be implemented soon, clustering will follow soon. Carlos expects that the ntuple will be available within 2-3 weeks.

Edited: 08/21/12, 09:52 
 
12 GeV preparations
====================
   Alex reported on meeting with T.Keppel, written summary was given by Charles in a separate Elog entry 
(https://hallaweb.jlab.org/dvcslog/12+GeV/106). 

- Concerning schedule current target is Fall 2014, with installation during summer 2014. It is unclear the impact 
of GMp running on DVCS (so far it is not annonced as a "parasitic" running).

- Concerning space, the TED space looks interesting. To be discussed further next week when more people will be 
online.

6 GeV analysis
===============
   Malek reported on data quality and time corrections with latest production files. A few problems were known 
(broken blocks), some other need further investigation (see corresponding elog entries 
https://hallaweb.jlab.org/dvcslog/DVCS2/149 and https://hallaweb.jlab.org/dvcslog/DVCS2/150)

pi0 paper
==========
   We may need to publish an erratum to correct for the factor 2 missing in r_{TL'}. To be discussed next week.

 12 GeV preparations
=====================

- We talked about the email by Cynthia concerning space in the Hall for the preparations. We thought that the Hall has the advantage of being a very "realistic" testing space, but it becomes unavailable during the commissioning of the accelerator and the Hall. Charles will write to Cynthia asking for another place with 24/7 access.

- We discussed DVCS possibilities in Hall C in relation to the 1-day workshop (Nov 14, 2012) that will take place in Orsay. It would be nice to have some estimates of backgrounds and resolutions we could achieve with the Primex calorimeter in Hall C, with and without the sweeping magnet. Another issue is the electronics (ARS vs HallD flash ADCs).

 6 GeV analysis
================

- Waveform analysis files are finished and transferred to JLab. Stub files are under /mss/home/munoz/DVCS2/alex2ndprod/ Malek will look into time corrections and check everything looks ok.

- Rafayel has posted a report on the Geant4 implementation of the DVCS setup. Maxime will add some details on the calorimeter part that he implemented. Send comments or questions to Rafayel.

 pi0 paper 
===========

- Brief discussion on the wording of the new additions by Eric.

• Starting next week we will meet on Monday at 9:15
• Tanja Horn has approched Carlos and Charles to discuss possibilities of running DVCS in Hall C. The idea would be to put together a compelling program of exclusive (and semi-inclusive ?) reactions including pi0 production and DVCS. The idea was prompted by the recent disappointing PAC results concerning pi0 studies. The current idea is to have Tanja join us at the DVCS collaboration meeting in Orsay (Nov 12-13, 2012). Discussions are on-going.
• Carlos reports that the waveform analysis of the calo data was completed. The data are beeing transfered to JLab. Carlos expect the files will all be at JLab by next Monday. Malek will perform timing correction. After that the ntuples will be created.
• Angle calculation. Malek and Carlos found the bug in the comparison of the angle of proton elastically scattered calculated (based on beam energy and measured momentum) and measured in the LHRS. Now that the bug has been fixed, a ~ 1mr systematic error remains. Charles states that this is the type of mispointing ususally obtained with the HRS, Carlos wonders why the mismatch is systematic instead of random. Now that this issue is fixed, Carlos reminds us that the original question was the actual location of the calorimeter. Elastic data revealed a 0 to 6 mm lateral displacement of the calorimeter. The deplacement amplitude depends on kinematic and even on the day of the data taking. The HRS check was just to rule out a HRS mis-pointing. The question remains where is the calo?
• Eric just posted a new version of the pi0 results: clearer figure, new text that is hopefully clearer and that doesn't introduce new notation. Goal is to put in the archive soon. We wil discuss this during next week meeting.
• DVCS3 (12 GeV schedule) Al Gavalia and Thia had a meeting last week. Unfortunately Charles could not attend. From what we know the parallel running with GMP is stillbeing discussed.

• Discussing JLab computing survey: Carlos encourages us to fill it, he explains why he is not happy with what is offered at JLab. We talked about: transfering data, changes in available software, etc..
• Wave form analysis: almost all the runs have been analyzed. It should take about a week to transfer the runs to JLab.
• DVCS3 planning:
  • New about 12 GeV planning with Cynthia? No. Charles is having an ongoing conversation about the 12 GeV setup with the Hall A tech staff (eg A. Gavalian). At issue again, having Gmp and DVCS3 on the floor at the same time. The discussion is about the angles occupied by DVCS3 but also which scattering chamber to use, DVCS scat chamb has no window to the right where gmp would want one.
  • the blocks have been moved to the hall at 45deg on beam right. The stand and the black box+cable tray and it cables are there too. But not the rails (in some containers) and the patch panels are in the storage building. We still have stuff in the Hall A laser room. The PMTs are ready to be shipped back. Michel Crouau is ready to retire, think about last questions to ask him.
• DVCS1:pi0 update from Eric elog:https://hallaweb.jlab.org/dvcslog/Results/179 Eric received Carlos's comment but has not acted on them yet. We discussed about the need for a new publications for the kinematic versus W (constant Q2) or helicity dependent? Helicity dependent cross-sections is maybe the one with the most interest. Constant Q2 is a subset of the previously published data so it is not that new. Publishing means posting on the arxiv.

Present: A. Camsonne, C. Hyde, C. Munoz-Camacho, J. Roche, V. Sulkosky.

• Report on the recent meeting with Cynthia
  Charles and Alexandre C. met with her. Very positive meeting but her follow up is confusing. It looks like she is still trying to push the GMP to be on the floor at the same time as us. PREX is not at the front of the schedule anymore (money, beam quality, etc..) but that might change, it is not clear how that collaboration will react. It is also not very clear why she is trying to get the two experiments on the floor at the same time. It is not clear if we are going to run in one or two periods. No explicit discussion about the state of beam line instrumention at the beginning, but Moeller should be with the old warm magnet still. Did not talk when we will be taken off the floor, or what will be the efficiency scheduling, the first priority was to get on the floor.
  The GMP people are : Bogdan, Shalev, J. Arrington. The proposal is there: http://www.jlab.org/exp_prog/proposals/07/PR12-07-108.pdf It is a one arm experiment that wants to use the two HRS simultaneously, they also want high current.
• Space issue for DVCS3
  Charles vonlunteered the space at ODU and let Cynthia knows about that. For memory our dark box and and cable tray got moved out of the EFD building into Hall A: space is still a very high commodity at JLab. Carlos is basically ok but concerned about last minute mechanical issues. Charles is more concerned about DAQ support. If we work for a while at ODU, we will probably have to do an assembly at JLab before the final assembly in the hall (why?? I did not get that).
• DVCS2 analysis:
  • 5 kinematics out of 8 have been replayed: one more than last week. Malek is working on timing corrections after each report. Final ntuples by september at JLab. It takes time to do this first pass, it is not only an issue of CPU but also of man-power.
  • Simulation: Last week we discussed the large effect of the resolution is twice worst if the photon falls in betwen the block than if the photon fall within the block. This was traced back to the number of blocs considered in the clustering: if the eneryg in one block is too low then that block is not considered to find the locus of the hit. This results in a bad resolution for in between-blocks photons. The simulation threshold has been lowered from 1 GeV to 100 MeV, in that situation the resolution for in-between-blocks photons is only 30% worst than in-blocks photons. Is this a real life effect? Well maybe in DVCS1 because of the trigger on the electron. In DVCS2, that should not be an issue but in time we will have to match the clustering trigger between the simulation and the data analysis. The first pass analysis (right now being done at Lyon) is doing wave form analysis, the threshold for looking for a pulse is 20 MeV, so lower than the clustering threshold .

Some notes on today's meeting:
-----------------------------------

Online: Pierre, Malek, Julie, Sylvain, Charles (part-time), Alex, Carlos.


1.- nDVCS proposal - Malek posted some projections in ELOG
    (DVCSNeutron/107). Still not fully clear how one single beam energy
    allows the separation of DVCS^2. It seems that the acceptance in xB
    might be enough to get reasonable error bars. Also, it seems that xB
    is correlated (if so, why?) to the missing mass so that binning in mm2
    allows to extract DVCS^2(!). This needs to be investigated further.

2.- E03-106 paper - Review of comments (essentially those by Kees and
    M.Garcon). Charles will talk to Kees about the formulation of the
    abstract. We agreed also to mention the impulse approximation in the
    abstract and slightly change the wording in the text (around Eq.4).
    Charles will take care of these wording changes. Once done, we'll
    answer to M.Garcon and submit the paper next week when Eric is back.

3.- PbF2 blocks quote - Julie discussed the details of the previous order,
    as well as the details of a similar order by Mainz (see  ELOG
calorimeter/250). Mainz specified a
    radiation hardness requirement as part of their order. Not clear if
    SICCAS did test the blocks for radiation hardness before shipping
    them. Julie will try to find out and request the final quote for us
    soon (Kees needs it by mid-August).

4.- FEL tests - Julie submitted the proposal. It has been basically
    approved (there is no formal approval process for FEL). Julie
    requested the FEL sometime from 10/15 to 12/15, we don't know yet the
    exact dates that they will provide us with.

    Julie has ordered the curing lamps, the estimated delivery date is
October 3rd. She will work on a setup to hold the curing system.

    Sylvain presented further results on block transmission (details at
http://www.jlab.org/~jroche/deb or in ELOG entry calorimeter/251).
Transmission was measured at different (transverse) positions between the
target-side and pmt-side.

5.- Calorimeter design - Pierre is working on the design of the new
    calorimeter (PMT/base, LED, etc). Alex/Charles will ship him an old
    block+PMT so that he has all the details.

6.- Collaboration meeting - Oct 15-16 (after DNP) seems to be the
    preferable option. It would be good to invite external speakers on
    different topics (Charles sent an email with a few topic suggestions
    before). Choice of topics/speakers to be continued offline.


 NEXT MEETING: Tuesday Aug 14 at 10:00/16:00 - Please join!
=============================================================

Some notes on today's meeting. Carlos.

---------------
Online: Eric, Malek, Carlos

1.- nDVCS proposal.

- At this moment Malek finds similar error bars in the DVCS2 extraction
  with one or two different energies. I think something is wrong, and it's
  not what I find when I do that with my code on the proton. Malek and I
  will work offline to solve this issue.

- Usual (but shorter) discussion on kinematics: 1 or several Q2, blabla...

2.- nDVCS paper.

- Quick review of comments to the paper so far (Kees+Arrington). No major
  issues. Eric will send the paper to all authors (only sent to the Hall-A
  Collaboration so far).

- Discussion on M. Strikman's comments on FSI. Not easy to estimate what
  he asks for. We should add a sentence about it in the paper, but not
  clear which one...

- Eric and Malek are going to circulate a "new version" of the paper with
  Simonetta's model and discussion. We should later decide if we take it
  or keep the previous version.

3.- Collaboration Meeting.

- Eric will be available in October (except for 10/8), and Malek will only
  know in September. Malek also volunteers to host the meeting in Tunisia
  if people are interested!


NEXT MEETING: Tuesday 8/7 at 10:00/16:00 - You're welcome to join!
=====================================================================


Mon, 30 Jul 2007, Carlos Munoz Camacho wrote:
>
> Hello,
>
>   If enough people are available, let's meet tomorrow for a short meeting at
> 10h/16h. Possible topics:
>
> - nDVCS proposal
> - Fall Collaboration Meeting
> - Long paper update (if Franck is there)
> - etc..
>
> Carlos

Dear colleagues:

   Find below some minutes from today's meeting.

Carlos

----------------
Online: Charles, Malek, Pierre, Carlos.

- nDVCS proposal: Discussion on Malek's latest estimate of DVCS^2 with VGG
  model. Some issues raised on how could both the imaginary and real part
  of the DVCS amplitude be very small and, nevertheless, obtain a very
  large DVCS^2. This seems suspicious at this point and Malek is going to
  investigate further. Notice that at this point Malek is only including
  the 1st and 3rd terms of equation 66 in Belitsky's paper and neglecting
  the 2nd and 4th terms. To include the 2nd and 4th terms, we need the
  imaginary part of CFF Etilde which is not provided at this moment in the
  VGG code (I'll contact M. Guidal). Malek can at least include the first
  2 terms within the 2nd term (those not depending on Etilde), i.e. assume
  Etilde=0, but include _all_ terms depending on H, Htilde and E.

  General agreement on the need of two beam energies to separate the
DVCS^2 term regardless of VGG calculation (we cannot based our physics
results on the predictions of a model).

  Malek will continue working on the proposal by estimating the error bars
on the extraction of each coefficient when using two beam energies. For
the acceptance at 4.8 GeV he will, at least for the moment, use the same
simulation at 6 GeV and correct by hand the difference in the HRS momentum
bite. Other option is to use Pierre's fast simulation (B**h). Ideally (and
later), Franck would produce a Geant simulation at 4.8 GeV.

- nDVCS paper: Malek asked about showing Simonetta's prediction in the
  nDVCS paper. Pierre preferred not to. According to him, VGG model is
  shown to motivate the JuJd sensitivity whereas in Simonetta's model JuJd
  is fixed (and somehow taken from the lattice). Charles had not read
  Simonetta's paper and had not yet an opinion. I myself had no strong
  opinion either.

- Funding: Kees has a "small but non-negligible" chance of getting money
  to buy 100 PbF2 blocks beginning of August. Charles has asked Kees to
  ask Sirish for the specs of the previous order. No reply yet. Charles
  may contact Sirish directly. If JLab is buying the crystals, the request
  for a quote must be done by JLab. Charles will follow up on it.

  Side comment: Charles have asked Javier Gomez to be the physics liaison
for E07-007. No answer yet.

- pi0 analysis/paper: Pierre is still working on kin2 results. We will put
  the paper on hold for some more time.

- Some discussion on (prospective) students about timing and possible
  assignments. Also, Charles will probably send out a postdoc ad soon.


NEXT MEETING: Tuesday 7/31 at 10h/16h. Please join!
====================================================


On Mon, 23 Jul 2007, Carlos Munoz Camacho wrote:

>
> Dear colleagues:
>
>   Let's meet on Tuesday at 10h/16h for our "regular" DVCS meeting. On the
> menu:
>
> - nDVCS proposal
> - nDVCS paper
> - pi0 (analysis + paper status)
> - Funding
> - FEL tests and proposal
> - Any Other Business
>
>
> Carlos

Here are a few minutes on today's meeting. Feel free to comment, add or
correct:

Present: Alex, Pierre, Malek, Julie and Carlos

1.- nDVCS proposal. Long discussion on beam time request and physics
    goals. Options considered:

a) Only Q2=1.9 GeV2 with two beam energies:
   Pros: physics goal clear (DVCS^2 separation)
   Cons: hard to justify the 600h requested (especially the 450h at
4.8GeV)

b) Two Q2 points with 2 beam energies each:
   Pros: easily fits into a 600h request.
   Cons: hard to justify the physics of a Q2 dependence on the neutron
(that we will already have on the proton)

We discussed the pi0 cross-section measurements and whether it should be
part of the goals:
   Pros: it can add beam hours to the experiment
   Cons: hard to justify its measurement that so far seem very small on
the neutron (from our previous data).
An L/T separation seems out of reach, and without it, the physics of the
measurement much less interesting.

No real agreement reached. Absents are welcome to give their views on
this. Malek will continue to work on the proposal with a choice of his own
at this point, which can be revisited later.

2.- Discussion on the MRI review. Pierre pointed out that we should never
    justify the extension of the calorimeter based on the increased
    t-acceptance for DVCS and only mention the pi0 measurement
    improvement.

3.- FEL proposal. We decided to submit it soon, after the agreement of
    those absent. This will be a test of the procedure (with 12 blocks).
    If everything goes ok a larger proposal will need to be submitted to
    test all blocks of the new calorimeter.

   We agreed to start these tests in late October when Pierre will be at
JLab.


That's all folks!

Carlos

PS: Next meeting Tuesday 7/24 10h/16h. Plan to be there: on fera l'appel!

Here are a few notes on today's meeting. Feel free to correct, add or
comment on anything...

======

Present: Alex, Carlos, Eric, Franck, Malek

1.- Malek on nDVCS proposal:

a) Generally agreed to start writing the proposal under the assumption of
one single Q2=1.9 GeV2 and two beam energies, with the goal of separating
DVCS^2.

b) Latest ELOG entry by Malek (Results/151) shows the statistical
uncertainty expected in the extracted coefficients assuming same
luminosity as previous experiment (and a single beam energy). Some
concerns raised (by me) about the fact that no systematic uncertainties
were considered in that study. I'll try to be more clear in a separate
email.

c) Malek described the first plot of that same ELOG entry which he claims
explains the bad chi2 on fits of the unpolarized cross section on the
neutron. He attributes that asymmetry to the higher inefficiency of some
blocks. He may try to estimate this inefficiency using a physics channel
(pi-?) and correct for it if possible. Notice that in principle this
asymmetry could be due to some sine-like physics channel, although all
contributions to the unpolarized cross section should be cosine-like and
therefore cancel on that asymmetry.

d) CONCLUSION: Malek will write within the next week a first sketch of the
proposal to be discussed in the next meeting. If enough time, he will look
into point c) above.


2.- Eric on nDVCS paper status:

a) Discussed Markus (and Marc's) comments to the paper. None of them seem
major. Eric will implement the changes by the end of the week and send it
to us. After agreement (or further discussion in next week's meeting if
needed), he will send it to the Hall A Collaboration (hopefully next
week).

b) Some discussion on whether to include Simonetta's new predictions into
the plots. No clear agreement reached, to be discussed later (we can
produce the plot anyway and decide later).

c) Some discussion on the infamous factor 5 in the linear combination of
Ju and Jd we measured (Marc's remark). Eric might ask Marc to think about
it, but it's probably a model-dependent result with no much physics
foundation.


3.- Franck on long paper preparation:

a) He will write a sketch soon and ask for contributions.

b) Small discussion on whether 1 or 2 (proton and neutron) long papers.
Discussion postponed after the long paper is more advanced.


NEXT MEETING: next Tuesday July 17th same time (unless nothing to discuss)
------------


On Mon, 9 Jul 2007, Carlos Munoz Camacho wrote:

>
> Dernier rappel ;)   A demain! - Carlos
>
> On Fri, 6 Jul 2007, Carlos Munoz Camacho wrote:
>
>>
>>  Bonjour,
>>
>>    Un rappel du meeting qu'on avait prevu mardi prochain (10 juillet) a
>>  10h/16h. Dans l'agenda:
>>
>> >   - nDVCS 6 GeV proposal status (Malek, 20+10')
>> >   - E03-106 paper status (Eric, 5')
>> >   - pi0 paper (Charles/Pierre, 5')
>> >   - Long paper: plan & todo list (Franck, 5')
>>    - (?) Note Charles "asymmetries & sections efficaces" (ELOG:Results/150)
>>
>>  Si quelqu'un a des transparents, merci de les envoyer ou poster a l'avance.

Information for run 4127, End of Run Comment:
Run_type=LED,beam_energy=0,beam_raster=off,comment_text=Chain stability,daq_mode=DVCS only,dvcsarm_distance=0,dvcsarm_theta=0,leftarm_p=,leftarm_theta=,rightarm_p=,rightarm_theta=,target_type=Dummy
 

  - Accelerator has made some progress during the weekend. 5.75GeV setup
was no problem but still lots of RF faults. Hall A lockdown still
scheduled for wednesday 1600.

  To Do List until wednesday 1600
--------------------------------------------------------------------------

  General:

  - New HV cards need to be put into EPICS. 2 HV spares need to be located
(Sirish).
  - Get results from survey (Pierre).
  - Verify remote controlled switches, test, and write procedures (Alex).
  - Write procedures (Cath).


  Calorimeter:

  - Check Z-axis, check vertical limit switch position (Carlos).
  - Check-out DC current signals and read-out on all channels (Cath).
  - Pedestal run, commit it to DB (Carlos).
  - Leave HV and LV on for 2hr or so before taking any data.
  - LED scan, infer new HV, new LED scan to check (Cath, Carlos).
  - Long cosmic run (Carlos).
  - LED scan once in a while to check long term stability (Cath, Carlos).
  - Ask Barbosa for spare LED board.


  Tagger (Malek, JM)

  - Test all channels.
  - Pedestal run. Commit it to DB.
  - Leave HV and LV on for 2hr.
  - Take cosmics. Check with MC (some day).


  Proton Array (Gagik, David, Charles)

  - Repair one channel (amplifier).
  - Pedestal run. Commit it to DB.
  - Leave HV and LV on for 2hr.
  - LED runs, gain variation versus DC current (continuous LED).
  - Check time stability by several LED runs.


  DAQ (Alex, Matthieu, Michel, Bob)

  - MSQL DB for Proton-Array + tests.
  - Zero-suppression for Proton-Array + tests.
  - MUX issue need to be solved (until 2pm monday).
  - TS setup for multiple cosmic
  - Start and End of run scripts need to be moved to adaql2.
  - Final DB.
  - Timing with pulser (after 2pm monday).
  - DAQ stress test.


  HRS

  - S2 timing (Rob).


  Beamline (Charles, Sirish)

  - Check if all elements are functional, including Moeller, EP, Harp,
ARC, BCM, BPM, ...


  Misc

  - Scalers to be plugged in + tests (Alex).
  - Put everything to ground (Jack).

Present: Hari, Zafer, Pierre, Srish, Franck

Beam requirements:

Beam size: 50 < x < 150  75 < y < 250  with X:Y is 1:1.5
                       (ideal 80 by 120)
Beam position stability: +- 0.1 mm

Energy: 5.75 GeV

Polarization: as large as possible, >85% with super-lattice.

Energy spread: 6x10-5

Current: 3uA except during calibration ~80-100 uA
          ( no raster during 3 uA )
           current measurement accuracy of 1%
FFB on Energy and position mode

SLI will be monitored and Target OTR will be inserted on demand

Beam thru Compton Chicane with background of 200 Hz/uA or better

30 Hz pseudo-direct report.

  Present: B. Michaels, S. Nanda, K. McCormick, E. Voutier, J-M. Fieschi,
F. Sabatie, C. Munoz Camacho, M. Beaumel, P. Bertin, C. Ferdi, A.
Camsonne, A. Chanteleauze

  DAQ/Alex

  Electronics rack in spectrometer hutt. Remote controled plug is
working and will allow reboot w/o operator present. clrpc48 (PA/veto DAQ
when in the EEL room) is now in the CH for a few tests. Calorimeter crate
works fine. PA trigger has issues with a couple channels, needs
investigation (after B. Michaels is gone). Moving the acquisition to adaq
cluster in progress... some issues still. Bob Michaels has postponed his
vacations for another week to help setup the DAQ (big thank you!). Few
last channels of ADC for DC level monitoring need some work, Kathy will
try and do that before leaving.

  PA/Charles:

  Comparison of cosmics between reality and MC in progress, results next
week. Currently buidling a power supply for LED pulser. Last ADC cable for
DC monitoring has been built.

  VETO/Jean-Marc:

  No more HV problems. Two channels had shorts after the patch panel
boards went for repair. Just got them back from electronics group, will
test them again. VETO ready for transport at the end of the day today.

  Calo/Catherine/Kathy:

  - Catherine summarized her work on the LEDs. The corresponding technical
note can be found in the Elog and shortly will appear on the web page.

  - Four "broken" blocks have been repaired. 9 out of 11 spares are
already in the Hall. No clean work can be done in the Hall due to dust and
so on. If additionnal work on the calorimeter blocks needs to be done, we
have to do it some place else. All spares are already repaired.

  Misc:

  - Need to check position of epics/motor control place with 25m cable and
install them.

  - Meeting at 10am on friday with A. Areti for beam issues.

  Present: Charles, Gagik, David, Catherine, Alex, Jean-Marc, Franck,
Carlos, Matthieu, Eric, Malek, Sirish.

  Franck/Installation:

  - Electronics rack will move into the Hall on thursday afternoon.
Calorimeter unstacking will take place in the clean room on
thursday-friday. Blocks will be brought 5 by 5 to the Hall for
repair/stocking/restacking. DVCS detectors+platform will go into the Hall
early next week. RG213 will be moved at about the same time.

  - Few remaining question to Jack: RG213 cable management (carriages?).

  Sirish/Documents:

  - Need to write COO, ESSAD, RSAD. TSOP may not be needed (will know
soon). ESSAD is what we should focus one. Each subsystem should write
about 1-2 pages describing installation and associated hazard and security
features.

  - Still some money to spend quickly.

  Gagik/Proton Array:

  - repaired one of the worst-case block (horizontal tower). Only took
20min to replace the base which didn't work. Now, all PA channels are
fully operational.

  Carlos/Calorimeter:

  - Performed tests using continuous LED. Gain stability was better than
1% at 20uA and better at lower anode current.

  - Performed stability tests, using chronical LED scans over a period of
10hrs. Clearly the system needs about 1-2 hrs to warm up. After this,
stability is better than 0.3% (might be even better, since the test is
limited by the statistical accuracy of the LED scan itself).

  Eric/Veto:

  - Patch panels are being repaired by local electronics group. Everything
will be ready by the end of the week.

  - Writing 2 tech. notes, will be available shortly.

  Alex/DAQ:

  - problem with 2 ARS boards. Had to use spare. Now no spare anymore.
Faulty boards will be repaired/changed. Monday-Wednesday next week, Alex
and Bob will work together on DAQ, and integration into Hall A.

  - Will try new PowerPC CPUs.

  - Some remote switched have been ordered. Might need one more.

  Franck/DB:

  - script to send coda information to MySQL database on a run by run
basis has been written.

  Present: A. Camsonne, J-M. Fieschi, A. Chanteleauze, F. Sabatie, C.
Munoz Camacho, M. Beaumel, C.E. Hyde-Wright, D. Hayes, G. Gavalian, S.
Nanda, K. McKormick, J. Segal, E. Voutier, M. Mazouz

  -> Jack and everyone/Installation:

  - 08/02 :         DAQ side un-cabling. Preparation for transport.

  - 08/03 :         Move DVCS electronics to Hall A.

  - 08/03-09 :    * Plug-in DVCS DAQ to Hall A DAQ with Bob's help.
                  * Detector side un-cabling in clean room.

  - 08/09 :         Move DVCS detectors in Hall A.

  - 08/10-09/03 : * Unstack calorimeter, repair, stack again.
                  * Standalone DAQ tests.
                  * Pull RG213 from spectrometer hutt down to pivot.
                  * Slow control + HV cabling (decide where to put it).
                  * Patch Panels installation. Plug in RG213 and DAQ side.
                  * Write security documents.
                  * DVCS detector on platform on 09/03.

  - 09/04-09/16 : * Plug-in cables on the detector (RG213, etc).
                  * DAQ timing with Bob Michael.
                  * Detectors check out (about 8-10 days of tests w/ DAQ).

  Also discussed a few minor issues with Jack.

  -> Charles and Gagik/Proton-Array:

  Charles presented a possibility to actually look for elastic protons
into the proton array while doing the spectrometer check-out with HRSleft
(e-) at 20 degrees. To illuminate two towers, one can do different
settings moving back the DVCS stack by a total of about 80cm at the
furthest setting. We all agreed it would be beneficial to do such a quick
test while doing the HRSleft check-out.

  Gagik showed latest results on the P-A. Everything looks okay except one
block (badly located) which appears to be dead (most likely PMT). This
will be investigated when the DVCS detector is in the Hall.

  -> Eric/VETO:

  The HV short was investigated to come from patch panel. Electronics
group will help repair the electronic boards of the patch panel. Should be
done before end of next week.

  Other than that, everything looks fine.

  -> Carlos/Calorimeter

  Showed new results about block positioning (see ELog for details).
Determination of this block center is accurate to within 1mm2, but after
investigation, it seems that the amplitude dependency versus a move of
around 1mm is 5% (which remains to be understood). The LED method seems to
have a systematic error at least that size just because of positioning
error. With new position from scans (vastly improved the X-Y matrix of
block position), the discrepancy between last cosmics gain-matching and a
new LED run goes down to about 9% which is the record so far. A vote of
what method would be closer to the real electron or photon events during
the experiment ended up largely in favor of the LED method, we will see :)
Work on the broken blocks (broken solderings actually) will start as soon
as tuesday next week. Kathy has agreed to setup a table to work on this in
the clean room.

  -> Kathy/Slow control

  Kathy figured out the right setup for the VME scan ADCs and tested them.
Everything looks good. P-A GUI is there, Calorimeter GUI is there, just
miss the Veto GUI. The Veto guyz will interact with Kathy so that the GUI
is done. Good news for Kathy and bad news for us, Kathy got a job in
Washington State! Congratulations Kathy !!!

  -> Sirish/TSOP and misc items

  Standard operating procedures need to be written shortly. Sirish will
start and spokespersons will fill in the blanks.

  A survey meeting is absolutely necessary. We will try to schedule it as
soon as Pierre is back (August 5th).

  Some money remains to be spent, if you have items, let him know...

  Present: Charles, Eric, Catherine, Alex, David, Carlos, Gagik,
Jean-Marc, Matthieu, Malek, Astrid, Franck

  Malek and Jean-Marc/Tagger:

  All paddles have been tested with cosmics. Now will come back to paddles
which were tested "bad" during first try. This was DAQ problem though.
Analysis and decode classes are finished. Testing in progress. Next step
is comparison of results from gain match with what was done at Grenoble
for the 11 different shapes. If time permits, plan to redo everything.

  Charles and Gagik/Proton Array:

  Currently taking cosmic ray data for 4 towers at a time. The problem
with one tower (which was supposed to be a short or something) turned out
to be a cross-wire problem, so no disassembly was necessary. Comparison
with absolute gain calibration in ODU turns out rather badly. Geometry is
very different however (shape of blocks does matter for cosmics but not
for a LED). Monte-Carlo comparison will be coming soon. The LED pulser
board needs to feed power to 20 LED boards. It seems that the current
drawn is very high (4Amps total) which makes the VME power supply sag...
Solution is probably to plug in an external power supplu for that.
Fernando Barbosa is giving them some limited support on that. DC
monitoring has also issues, Kathy is helping to sort this out.

  Catherine and Carlos/Calorimeter:

  Carlos reports on his study to get find block centers. Most information
is in the Elog. Important things: position IS different depending which
LED is lit or which combination of bias for several lit LEDs. However,
position does not seem to depend on bias (good news). Also a good news,
the weighted average of the position for LED1 and LED2 and LED3 turns out
to be the same as the position of LED1+2+3 (as it should be). Conclusion
of this study by the end of the week. Catherine is writing final scripts
for getting number of photoelectrons, gains, doing linearity checks and so
on, so that it is fully automated when data taking starts. Most light
leaks have been blocked now thanks to Matthieu Jean-Marc and Alex.

  David/Spectrometer:

  David is working on the script to produce the HANA tree. It will be
available shortly. Gagik made a point that we should freeze (for now),
HANA's version so that everyone uses the same. Carlos will investigate
which version is most suited, most likely the last one. Also, Carlos will
write merging and Spectrometer classes in DVCS package once David has
given him the HANA output tree.

  Alex and Franck/DAQ:

  The change of VME CPU solved the DAQ hanging problem from last week.
Weird "empty" events noticed by Malek turns out to be a real bug for the
proton array/tagger trigger. Michel Brossard is working on that and will
fix this issue. Note that those events are only there when this trigger is
used as a real trigger. The calorimeter trigger doesn't have this issue.
Last few ARS modules will arrive next week. Our DAQ computer dvcsdaq had a
disk failure on 07/20. Had to change the disk and recover the data. Now
done. Zero-suppression mode for P-A is underway. Needs some more work,
especially getting the offsets right, and full blown test. DAQ GUI
programming underway (for now only for "newled" configuration). For now,
prestart and end run submit Elog entries with summary file. Need to make
entries in database as well. Will work on that now.

  Everybody/Run Plan:

  Draft run plan can be found at the following URL:

  http://www.jlab.org/~sabatie/stuff/runplan.ps

  Spectrometer check out will happen first. This will most likely be done
at lowest possible angle (19 degrees) where elastic scattering is still
possible (at the very limit of the momentum capabilities of the HRS left
and the a few ten Hz rates). It might actually be possible to put
protons in the proton-array in that configuration, but most likely needs
to pull back DVCS detectors a bit. Deep inelastic is also possible at low
angle with a few hundred Hz counting rates. So information will be given
to Ed Folts that Left HRS will be at 19 degrees, with negative polarity
and maximum momentum at start-up. Please verify run plan for the rest of
the settings. Colimator box issue: in or no? if we might have to use it,
knowing that we can put it in the "no collimator" setting, we should
require it + survey. Right HRS at 70 degrees. Polarity not chosen yet.

  For target issues: will make a push to get at least one beer can for
hydrogen, machined cell is okay for LD2, if we can't have the beer can for
that as well.

  Present: Bob, Charles, Eric, Malek, Pierre, Jean-Marc, Alex, Catherine,
Astrid, Gagik, David, Xiachao, Sirish

  Alex/DAQ:

  - Been working on PA/tagger crate lately.
  - Issue pending: crate is hanging after around 20 to 30k events, waiting
for an inhibit signal. More work needed to solve problem.
  - Bob Michael sent us a list with some propositions. Important
information: we will have only one trigger supervisor (left arm), even for
right spectrometer. We would like to have best S2 inter-paddle timing as
possible. Rob can help us take care of this.
  - General issues about DAQ and commissioning: trigger gate width
(40-60ns at the moment)? Pulse location in the gate? How many ARS channels
to read? whole 128ns? less? The possibility to record less channels should
be implemented and tested before run starts. Position of the pulse in the
ARS sample?

  Gagik and Charles/PA:

  - Take cosmic events. Issues with max number of events (see above). They
require MC file with "vertex" information for cosmics to simulate PA
paddles and trigger. Gagik presented a pulse parametrization which works
well for PA. LED for PA is not working too well, several issues to solve
(problem with LED pulse board?). Should start thinking (and implementing
DAQ-wise) strategy for data taking (and testing during the commissioning
period): 0-suppression mode, DVCS mode (read only PA blocks where proton
can land assuming it is a DVCS event).

  Malek/tagger:

  - taking cosmics, helped by Alex. 20 paddles have been tested. Can only
test a few because of cable issues. Currently working on DVCS software.

  Catherine and Astrid/Calo:

  - LED with new script (all blocks at once). Same results as last time.
  - Astrid showed that there was a 16% spread in photo-electron yield
using information from cosmic runs and LED. This needs some more work.
More news next week.

  General:

  - we will soon start a Elog thread on items that are missing (mostly
cables at the moment). Everybody should add to it so we know where we stand.
 

attendance:

P.Y. Bertin, C.E. Hyde-Wright, G. Gavalian, S. Nanda,
A. Camsonne, C. Ferdi, A. Chantelauze, M. Mazouz



Reports:

P. Bertin,

HV Cables for Tagger on order, not yet delivered
Need 60 lemo to BNC adapters for Tagger
Added note to elog regarding preference for 15cm target cells.
Need Beam-Line expert for experiment (Charge, BPM, Raster, Moller Beam-
energy)
Target will have two loops (one H2, one D2, no spares).  Each loop has
5cm and 15cm cell.  Target will also have standard solid targets.



C.Hyde-Wright

Working on ODU grant renewal.
Refurbished two scintillators (and support)for Proton Array Cosmic-ray 
coincidence trigger.
Delivered monitor, keyboard, mouse for proton array DAQ computer in EEL
Delivered prototype PA block for Tagger Cosmic trigger (Hypertronix--SHV 
adapter also available).
LED pulser boards are functional, but final design switch to biasing led 
cathode rather than anode complicates the use.  LEDs can only be turned 
off reliably by setting bias to 5V (DAC=FFFhex)  This also requires 
adjusting the potentiometers on the PA LED boards.
One LED board and one low voltage board appear to be shorted 
(independently).



G. Gavalian:

Cosmic ray runs completed for two proton array towers.
Porting Calo ARS decoding software to Proton Array.
Will add spare cables to tray (HV and signal).
Working on PA HV controls



S. Nanda:

Compton Polarimeter will be a separate responsibility from other beamline 
issues during experiment.
Compton Polarimeter will be an excellent Halo monitor, together with
SLI (Synchrotorn light Interferometer).
Will purchase ADC monitor cables for Tagger, if we give specs.



M. Mazouz:

All channels of Tagger tested on scope, ok.
Broke 4 PMT in installation, 9 spares remaining.
Need a 1A +/-5 V power supply.



A. Camsonne

Fixed a bug in ARS addressing.
Calibrated Proton Array, Calorimeter, timing in cosmic ray setup.
Will create separate CODA DAQ for Calorimeter cosmic ray running and
PRoton ARray+Tagger running.
Assisted with Proton Array DAQ



C. Ferdi

Presented results on Cosmic ray and LED calibration of Calorimeter (see 
Elog).
Mean signal from Cosmic rays is 40 photoelectrons, with a dispersion block 
to block of 2 pe (except four blocks known to be poorly assembled).



A. Chantelauze.

Wrote report on internship, will defend by videoconference tomorrow.





Next Meeting, TUESDAY, July 13, after the Hall A meeting.

Minutes of E00-110 DVCS meeting 6/30/04
Proton Veto (Grenoble)
A-Layer assembled
B-layer started
PMT amplifier bandwidth was reduced to 100MHz to eliminate
oscillation.
50 Ohm output impedance added also,
Will try to restore output impedance to 10 Ohm
  (10 channels tested 7/2)
C.H.-W. agreed to provide paddle for Cosmic Ray
trigger for tagger (done 7/2).

Proton Array:
two Cosmic ray trigger paddles and mounting brackets now
available.
Tagger shielding/mounting cone conflicts with 1/2"Al
shielding plates for forward towers.  Shielding plates
will be trimmed.
Login on/off for DC LED does not function.
Potentiometers on LED pulser boards must be adjusted to
allow 1) maximum light output for pulse LED 2) Turn off
all LED by setting voltage DAC to FFF(Hex).
Sirish has promised to purchase a high quality monitor for
Proton Array DAQ in EEL (to be reclaimed later for
Compton Polarimeter).

Alex Camsonne:
Working on EPICS control of XY table
Working on Proton Array DAQ

Bob Michaels will be on vacation Aug 10-30.

General Discussion:

- Tagger soon received in few days and guys from Grenoble coming next week
- Need organisation and device (oscilloscope, computer, coda...) in the EEL
for working (Tagger people, Proton array people and Calorimeter people)
- Dismount Calorimeter before moving it in the Hall A and mounting it in the
Hall A (It takes one week, no modification in the schedule)
- Bob Michaels in vacation after Happex and until 23 or 25/08 (Bodo could
replace him)
- 50 % beam time in addition ( all calculations done with 70% polarisation
and now for Happex 86% polarisation). Don't tell this to Kees and Larry...
- Need meeting with accelerator's guys after Happex (Sirish has asked the
maximum current we need which is linked to the efficiency machine: 5micro
for proton and 6 micro for neutron)
- Need one guy in charge of the luminosity monitor during the experiment


Gagik has presented some results about the calibration of the left
spectrometer (other elog report), Alexander about the DAQ (in attachment)
and Astrid and me about the LED studies (other elog report). 

Catherine

  Presents: G. Gavalian, D. Hayes, M. Mazouz, C. Ferdi; A. Chantelauze, A.
Camsonne, P. Bertin, F. Sabatie, R. Gilman

  Minutes:

  -- M. Mazouz: showed pictures of the tagger fully assembled in Grenoble.
It will be sent to Jlab before this weekend and will be here next week.
Malek also talked about MC results for the tagger. New simulation with new
mechanical description of tagger system shows that rates are everywhere
less than 1MHz at 4MeV threshold except for one paddle. Malek suspects
that positionning of side plates creates an unrealistic top-bottom
asymmetry and will investigate this. Malek also showed results
of MC wrt what paddles are hit when a certain proton array block is hit
(by a proton). He will put this into correspondance table so that it can
be used in the trigger if necessary, or for quick offline analysis.

  -- Astrid: showed updated results on the LED monitoring. Removing one of
the collimator's plate increases the number of photoelectrons by a factor
10. A new light guide is currently under fabrication, which should improve
light collection and maybe allow one to use better collimator (with 2
plates). Cross-talk, which was a problem in the first system studied last
year, seems to be completely gone now (good news!). PMT linearity was
studied as well. Comparing the mean of the integral for two LEDs and then
for the sum of the two, linearity was determined to be of order 1.4%. This
result was however not recovered when comparing photo-electron yields.
This remains to be understood. Lastly, Z-dependence was checked to be of
the order 1% per mm, which is okay to work with since the estimated z
spread of blocks on the face of calorimeter should be within these specs.

  -- David: Cabling of trigger and ARS just started for Proton-Array and
Tagger. Should be finished next week.

  -- Gagik: aggreed to check on the spectrometer setting for check-out so
that we can send a complete setting to Ed Folts asap. He will also check
the mounting of external paddles for cosmics with the proton array.

  Present: P. Bertin, C.E. Hyde-Wright, G. Gavalian, K. McCormick, M.
Mazouz, D. Hayes, A. Camsonne, C. Ferdi, A. Chantelauze, F. Sabatie

  Franck: Discussed the installation meeting with everybody in more
details. The installation schedule is mostly constrained by the first two
weeks while we wait for septa to be desinstalled. There will only be 7-10
days to check-out the detectors in the final configuration before Hall
locked period (starting Sept. 10th). This Hall locked period is still
unclear. We will probably be able to access the Hall in controlled access
if needed.

  David: showed the PA/tagger cabling scheme (trigger and ARS). Charles
and David payed attention to not get PA blocks and corresponding tagger
paddles in the same ARS module because of cross-talk. Attention was not
paid particularly to block-transfer issues since 0-suppression mode will
be chosen and will probably sparcify the data. David used a reversed
numbering scheme as we used in the Monte-Carlo. We decided to use MC
scheme so he will update his slides and make them available.

  Astrid: Details about LED system check-out using charles' light guide.
It turns out the system is very dependent on the alignment and very little
photons make it to the block. More details are available in Astrid's
recent ELOG entry.

  Alex: worked with M. Brossard on the new logic unit. Now operationnal.
Many scalers can be programmed in this unit (it contains a FPGA). Still a
few things to tune in DAQ. New trigger operationnal.

  Gagik: Worked on software a bit. Found a way to simplify library
structure. Will check in changes in CVS.

  Present: Ed Folts, Jack Segal, Sirish Nanda, Al Gavalya, Pierre Bertin,
Franck Sabatie.

  Minutes:

  Installation starts Aug 2nd (monday).

  Aug 2-8

    In the Hall:

        - Left and right HRS detector work (Jack)
        - FPP Rack dismount (Jack)
        - DVCS Patch Panel mount (Jack)

    In the EEL:

        - Detector uncabling (RG213) (us)
        - Clean up, ready up for moving cables, then detectors (us)

  Aug 9-15

        - Install DVCS Racks in left HRS hut
        - String one 25m (XY-table) cable to check where to put
        all slow control racks and HV. Then pick the location and
        install all that.
        - Ed can move the left HRS a bit away from beam line so that
        we can start stringing RG213.
        - At the end of the week, Septa are out.

  Aug 16-22

        - Install BigBite stand (some welding, machining, survey necessary)
        - Start install of scattering chamber.
        - DVCS team works on acquisition.

  Aug 23-29

        - Bring DVCS stand in.
        - Put DVCS stand on Big Bite stand (requires some welding,
        machining, survey, etc)

  Aug 30-Sept 6

        - Cabling (RG213, slow control, HV, ...) starts when DVCS stand is
        on place.

  Tests can begin with full detector as soon as cabling finished (which
should be fast. Should leave about 1week for tests before hall locked
period (Sept 10-20).

  Additional notes:

        - Large Cerenkov detector will be in left HRS.
        - Pion rejector might have bad blocks, needs to be checked with
        Eugene.

---  Charles:

  18 towers are installed, 2 last will be ready by the end of this week,
installed next week. All cables are in. Extension cables are ordered.

  ADC for DC monitoring still not working. Kathy and Michel will look into
this friday.

  LV power supply built, will be tested soon.

  David is looking into a scheme for exclusivity analysis w/o photon
energy (only angles), will be discussed next week.

---  Gagik:

  HRS Calibration tech. note is available on the web page. Working on PA
database.

---  Alex:

  New trigger installed, cables plugged. Everything works. MUX box
installed. Cosmic trigger with external paddles currently under scrutiny.

  PA trigger installed, will be cabled by PA team next week.

--- Malek:

  Implemented tagger geometry, with associated shielding and mechanical
support. Rates dropped compared to before, all under 10MHz. Final results
next week.

--- Pierre:

  Meeting with survey guy to talk about the report they produced from
first survey. Turns out that we have the 3 euler angles of the calorimeter
wrt the black box well described but the location of the calorimeter
itself is not clear. It will have to be re-surveyed. Pierre suggests
videotaping next survey to know what is being done!

--- General discussion on PA trigger cabling scheme

  The discussion was long and I will only report the conclusion: it would
be great to have 2 GEn bars (10x10x160 cm3) on top and bottom of the
proton array for cosmic ray calibration. Charles will ask Bogdan about
this. In any case, there is probably a smart way of cabling the ARS, the
trigger and so on. Gagik and Charles will think about this for next week,
before the cabling starts.


  Don't forget next meeting: wednesday june 9th, 3pm, A216

  Sincerely,
  Franck

Two different kinds of analysis will need to be done on spectrometer data:

1. Single arm analysis and calibration.

   The purpose being to calibrate and monitor detectors in the
spectrometer, we need to look at and keep many variables : all ADC/TDC
values of VDCs, S1, S2, Cerenkov, Pion Rejector... (no TDC is available in
pion rejector).

2. Coincidence analysis.

   Only a few variables per detector will be enough:
     - S1, S2 and Cerenkov sums
     - Pion rejector 1 and 2 sums
     - S2 X,Y,theta,phi
     - PID, quality of track

   In addition to that, useful physics variable should be kept :
     - delta,theta,Y,phi at the target (vertex)
     - t_vertex
     - Px,Py,Pz, X,Y,Z at the focal plane
     - Px,Py,Pz in Hall coordinates
     - X, Y, theta, phi at the focal plane (to doublecheck)
     - Event number (CODA)
     - Event type (electron,pion,...)
     - Helicity
     - X,Y,Z of BPM
     - S2 tracking (optics_0) (timewalk)
     - Lots of scaler values... (to be defined!)

Several important issues were raised during the meeting:

- Full electron PID tuning with single arm is sufficient. All calibrations
of spectrometer need only single arm except DVCS
detectors-spectrometer coincidence timing! 

- S2 timing done zith cosmics which cross 2 paddles at the same time.
Small cables can be added to correct for timing spread.

- Status of calibrations : which detectors be calibrated after HAPPEx ?

- Timing issues (a dedicated discussion on the DVCS trigger might be
  needed). Bob and Bodo seem to check time at the scope with cosmics. No
software is necessary.

- The right spectrometer may be used as a luminosity monitor. The minimal
  angle where we can go needs to be investigated.

- Necessity of a sieve slits calibration run? Effect of the pointing
accuracy of the spectrometer in the experiment resolution/acceptance. This
needs to be investigated (by who?). A lower energy might be needed (time
issue), a proton array elastic calibration run might take place if a lower
energy is available.

- Necessity of collimator in spectrometer ?

- What targets that will be available to us ?

- Macros for VDC, S1 and S2 efficiency are not "well centralized" and
  not easily available.

- Some interesting variables of HANA seem to be private and
  inaccesible. Requests should be made to the HANA developpers team to
  write the appropiate methods. An example of these variables are the chi2
  and error of track fits.

- We will need to tag a certain version of the analyzer soon (with a
version of ROOT to go with it).

- Automatic splitting of files seem to be ok with everybody. A SILO
  file size limitation exists (2GB). File size for subsequent analysis
should in principle not increase the CODA file size.

- No delayed helicity scheme (to be checked with HAPPEx2).

- Cerenkov will be there during HAPPEx, but after discussion with HAPPEx
  guys, trying to calibrate during HAPPEx is out of the question (VDCs for
  example won't be there).

The mainstream analysis strategy seems to favor the stand-alone + merging
procedure. A merging script which matches event number in both independent
trees needs to be written.

David Hayes and Gagik Gavalian will take care of the spectrometer
analysis.

In next week's collaboration meeting a list of final variables
will be available.

Everyone agreed to have weekly meetings from now on. Wednesdays at 2pm
seems to be a good time, starting in two weeks (after the collaboration
meeting).