G2p Analysis Minutes

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Minutes of the weekly analysis meetings


9/21/2011: Present: Karl, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, Alex, Vince, Toby, JP, Yuxiang Zhao, Yi Zhou, Zhao Zhang

  • Pengjia:

1) Copied HAPPEX DAQ (HARDWARE) into the right HRS and got it work.
2) Tungsten colorimeter is still under testing by Arne's student. We was told
that it need two more weeks to finish.
3) Show a few slices about the helicity signal that will be used during in g2p.

  • Kalyan:

1) Working on 3rd arm DAQ. It is basically working right now. Doing the test with dE plane.
2) Worked with Whit(Engineering group) to design the support of the magnetic shielding.
The shielding material has been ordered.

  • Jixie:

1) Working on the simulation of C12, LHe, CH2 and LH2 with sieve slit in position. Trying to finish
the reconstruction code and verify if the we can separate the elastic peak of C12 from that of LHe.
Check here for details. This figure shows the CH2 elastic peak at 1.159 GeV beam energy.
The momentum elastic peak of helium and Carbon start to overlap after energy loss. Note that the momentum are not
reconstructed momentum. Smeared be the VDC resolution and reconstruction resolution, these 2 peak will overlap even more.


  • Min:

1) Working on mudifi to fit Geant4 sieve slit data for target field reconstruction routines
2) Tuning the snake field map

  • Jie, *Toby:

1) The target field measurement with translation table analysis note is ready for group review.

2) The target field measurement on can surface analysis note is also ready for group review.
Toby also show some figure here.

  • Melissa, *Vince, Ryan :

1) Working on HRS DAQ. The DAQs for both arm are basically working.
2) Melissa Updated start_coda script such that it starts left HRS DAQ on adaql1 and right HRS DAQ on adaql2
3) Took cosmic run with left HRS. Will take cosmic run for right HRS soon.
4) One rack keeping losing power, need to trouble shoot for the HV card. Jack will take care of that
5) Ryan also looked into S1 and S2m TDC signal, some channels looks not abnormal. Need to spend more time for checking that.

  • Chao:

1) Working on 3rd arm DAQ with Kalyan. Will do pedestal run soon. 2) Measure the sieve slits for hole positions. They are all match the design.

  • Alex:

1)Working on test the intel CPU in DAQ.


9/14/2011: Present: Karl, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, Alex, Vince, Toby

  • Kalyan:

1) Working on 3rd arm DAQ with Chao
2) The magnetic shielding (netic cylinder + co-netic foil) order has been placed

  • Jixie:

1) Shift schedule is ready to sign. Called for checking the description. Karl suggested not to
open the 2nd period for user now. For those who have signed shifts in the 2nd period we will honor
them the shifts they signed.
2) Working on the TOSP for septum field mapping
3) Compare SANE TOSCA map with our NEW TOSCA map together with Oscar. Could not find the reason.
4) Running simulation to check optics plan

  • Alex:

1) Try to use intel CPU to replace the CPU board. 6~10 kHz DAQ rates is expected.

  • Vince:

1) Working on HRS DAQ with Melissa and Ryan; Roc3 is now not running
2) Check the lumi HV crate, one channel keep tripping off. (Nothing we can do so far)
3) Plan to change the Left HRS HV operation interface as the one used for the right arm.

  • Min:

1) Prepare for optic plan
2) Working with Pendjia for helicity signal in the HAPPEX DAQ

  • Jie:

1) Writing tech note for field measurement with translation table
2) Working with Pendjia for helicity signal in the HAPPEX DAQ. Made a comparison of time delay for 3 modeules.

  • Melissa:

1) Show the pre-shower|shower analysis result.

  • Ryan:

1) Working on left HRS ROC3. Took the structure fastbus interface from BigBite, but it does not work in roc3.
Will try to use an old CPU.

  • Toby:

1) Updated the G2p wiki with README (instruction) for replay
2) Writing the tech note of the target field measurement on the can surface

  • Pengjia:

1) Tested the dead time for various DAQ configurations. Check Elog entry 129 for details.

  • Chao:

1) Working on 3rd arm DAQ with Kalyan
2) Glued the broken dE plane scintillator


9/7/2011: Present: Karl, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, JP, Alex, Vince,Toby, Yi Zhou, Yuxiang Zhao

  • Karl:

1) The draft of run schedule is available here.
2) Discuss the safety and OSP|TOSP document issues

  • JP:

Welcome 2 USTC visiting scholar Yi Zhou and Yixiang Zhao. They will work on GEM and SOLID projects.

  • Jixie:

1) Agree to work on the TOSP for septum
2) Discuss the shift schedule and related things. Collaborators need to take 10 shifts to fulfill
the authorship requirement. Collaborators is not allowed to take TO shifts until got trained or
agree to receive the TO training well before shift starts.
3) Will talk to Oscar to find out the difference between old TOSCA and new TOSCA map for the target field. Here is the figure showing the difference between these models.
4) Design the magnetic shielding for the 3rd arm PMTs. Need to block 70 gauss field. Current chosen thickness, 0.062 inch, is over designed.

  • Min:

1) Reading tech notes and thesis. Prepare for optic plan.

  • Kalyan:

1)Remind the student that helicity signal in the HRS is delayed
2)Setting up DAQ crate for the 3rd arm
3)Working on the magnetic shielding

  • Jie:

1) Show his field analysis result

  • Toby:

1) Not finalize his field analysis result yet, will show the result later

  • Melissa:

1) Looking into the HRS s1 & s2m TDC, check Elog entry 128 for details
2) Check the Cherencov TDC spectrum, see Elog entry 127 for details
3) Still working on checking shower|preshower TDC

  • Chao:

1) working on 3rd arm simulation
2) working on 3rd arm SC, made a holder and will glue it at the rest of this week

  • Pengjia:

1) Ring buffer for HAPPEX DAQ works for helicity signal in the left arm. Will work on the right arm soon


8/31/2011: Present: Karl, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, JP, Alex, Vince

  • Jixie:

1) Working on optics plan with Min. Need to recalculate e-C and e-H elas rates for 5.7 deg 2.5T.
2) Confirm septum polarity before Howard connect it to the power supply
3) Will perform B vs I curve for septum in middle Sep. Chao and Min will join, Toby too.
4) Karl suggest get (from Doug) the long cable which is used to connect to the hall probe.
5) Will simulate what thickness will be good for a mu-medal to shield low energy protons.

  • Kalyan:

1) Working on the 3rd arm DAQ with Chao.
2) The dE plane of the 3rd arm is 6'(width) x 12'(height) in size, not 12 x 12. This is found
after it was opened. Chao will need to peel off the remainder glue and reglue it. Jixie will
check with Al about this change.
3) Kalyan agree to following replacing PMT for S1L2 (check minutes of Aug. 17 for detail).

  • Vince:

1) Will join G2P and work on HRS DAQ. A 3rd crate might be added in order to improve DAQ rates.
2) Will following the issue of HV crate of Lumi. (check minutes of Aug. 17 for detail).

  • Min:

1) Working on optics plan with Jixie.

  • Chao:

1) Working on the 3rd arm DAQ
2) open the SC with Kalyan. Will clean the opened SC and glue it back tomorrow
3) Need to run the simulation again for the 3rd arm using 6x24 size and latest design positions.

  • Melissa:

1) Checking on shower preshower. She will post her results to the elog.

  • Pengjia

1) Make a presentation about the DAQ plan for BPM|BCM.
After discussion we all agreed to put hardware into both left and right HRS crates such that each arm will have a complete DAQ system.

  • Jie:

1) Report that our measurement of the target field agree with the NEW tosca model with 1%.
Check his results file1 file2.


8/24/2011: Present: Karl, Jixie, Jie, Melissa, Ryan, Toby, Kalyan, JP, Chao, Min, Pengjia

  • Jixie:

1) The tosca model from SANE group was proved to be different from the one Robin recently
created. Check this plot to see how they vary. Both the field analyses from Jie and Toby also confirm that. Jixie will
talk to Robin to verify this.
2) Working on the Optics with and Min. A discussion with Jin Huang is ongoing.
3) The 3rd arm design is done. Karl mentioned that Al might have some small change in the design of
of the stand. Jixie will check this with Al.
4) Jixie will check the neutron background with the shielding with Poval.

  • Pengjia:

1) Got some progrss on the HAPPEX DAQ:
A) The ring buffer works with helicity signal now, will move on to ADC signal
B) Still working on the TCPIP program
2) Compared the BPM|BCM signal of HAPPEX DAQ and that from the scaler. It looks like HAPPEX DAQ give
better resolution. Pengjia, Kalyan, Alex and Bob will make the final decision which one to choose.
3) Arne's student is testing the tungsten colorimeter with an external heat source in the Hall. Pengjia is watching on this. 4) There are 2 options to put BCM|BPM signal into the data stream:
option A: use socket program to insert the signal into the ET ring;
Option B: integrate the hardware into HRS crate;
Pengjia will compare these 2 options then make a choice.

  • Min:

1) Working on the optics. Join the discussion with Jin and Jixie. See her report here

  • Jie:

1) Show the difference between old tosca map and new tosca map of the target field. Also show the field analysis result. Check details here.

  • Toby:

1) Showed his field analysis result using the new target field. The current ratio from his result
is consistent with Jie's result. But the position offsets still have some difference.

  • Chao:

1) Writing a tech note about the design of the 3rd arm with Jixie

  • Ryan:

1) installed S1 back to HRS, will connect the cables and DAQ

  • Melissa:

1) Practice the calibration of shower and pre-shower using xgt2 data

  • Kalyan:

1) Confirm that the trigger has been settled as the way we discussed in last meeting
2) Confirm that the 3rd arm DAQ can go up to 10KHZ


8/17/2011: Present: Karl, Jixie, Vincent, Jie, Mellisa, Ryan, Toby, Doug, Alex, Kalyan, Zhihong
By Phone: Chao, Pengjia, Min

Discussion about the trigger

  • Zhihong, Karl, Doug, Alex, Vince ... :

1) The HV of 3 channels in the (Left?) Cherencov are too high, need to be adjusted;
2) According to xgt2 data, the efficiency of S1 and S2 are still larger than 99%
3) The 2nd PMT in the Ledt S1 (S1_2_L) need to be replaced
4) S0 is already in the right HRS. We need to remove it
5) The HV of 2 channels of the Lumi crate (Slot 15, #7 and #8) should not be turned on,
otherwise they will cause the whole crate crashed;

After 3) and 4) fixed, the trigger for G2P will be the same as the regular HRS trigger.

  • Chao, Min, Pengjia:

1) Reported from UVA that the target have been cooled down and with 5T field on Tuesday, they are trying
for 2.5T field today.

  • Karl:

1) Bodgan told that S1m will not be ready for G2p;
2) Will organize rad.con.2 training and electrical lead training
3) As discussed with Jixie we need to place hall probe in the tunnel of both septa, encourage students
to help Jixie in measuring "B vs I" curve for septum coils;

  • Jixie:

1) Show the detection efficiency of the 3rd arm. It is about 85%. Check here for details.
The following table is the rate of the 3rd arm for current design:

Beam(GeV) Mom_Range(MeV) Hoffset(cm) Voffset(cm) Time(hours)
1.159 270~410 6 0 9.5
1.706 320~460 0 -20 9.9
2.257 320~460 0 -40 7.1

Please note that the detector efficiency is not considered yet.

2) Both of the 2 target field analysis from Jie and Toby shows that the current ratio is closed to 1.15. Jixie will
talk to survey group for checking the position for mistakes. Jixie also suggested Jie and Toby to compare the new target
field map from Robin to the exist one. If we can not explain this 1.15 current ratio, we need to measure the field on the can surface again.
3)Will measure the "B vs I " curve for septa when power supply ready. We need 2 gauss meters and 2 probes to place in the septa
during experiment. Will cost about $6000.

  • Jie:

1) Found that the current ratio is about 1.15. Will check bug for Toby and try to improve the field analysis

  • Toby:

1) Found that the current ratio is about 1.14.
2) Will check bug for Jie's program and try to improve the result

  • Melissa:

1) Checking the ADC of preshower and shower

  • Ryan:

1) Will look into the HV problem mentioned above.
2) Check the Y distribution at S1m to see if S1m will lose acceptance. This position is projected
from the focus plane. See the details here.
Note: we will not be able to use S1m.
3) Will clean the unnecessary cables for the HRS ;


8/10/2011: Present: Karl, Jixie, Chao, Pengjia, Min, Vincent, Jie
By Phone: Mellisa, Ryan, Toby

  • Karl:

1) Target is not cool down yet, still filling helium. Ryan, Toby and Mellisa are already there.
2) Can not find 2 cm SC
3) Got approved that we will have 12 days of 1.7 GeV beam (may be a old news to someone).
4) Tried to extend to run the experiment during Christmas

  • Jixie:

1) Talked to Bogdan and Albert for 2cm SC. There is no EXTRA 2 cm SC that can be used for us.
2) Talked to Brad and Bob about 10K Hz DAQ rate with ADC. Both of them are said there need some
efforts to make this happened.
3) Finalized the 3rd arm design:
A) Since 2cm SC is not available, we will switch back to 1 cm SC for the 1st plane;
B) The neutron shielding will be 30 cm thick and we will use the exist borated plastic;
C) The width of of SC plane will be extended from 6 to 8 inches;
D) We will put a removable 2mm aluminum shielding to shield low energy background from the target.
We will not use this shielding for 1.2 GeV. For 1.7 and 2.3 GeV, we will use it only if the DAQ rate
can not reach 10k Hz
E) We changed the detected energy range for 1.7 and 2.3 GeV.

4) Calculated the maximum raster size (requested by Karl). It is ok to extended to 11 mm. raster size assuming 25.4mm target cell diameter.
We will have the target cell diameter of 27mm, [1], which will allow to
extend to 11.5 mm.

  • Chao:

1) Simulated the 3rd arm. There is a bug in calculating the asymmetry. Need to recalculate the time
2)After fixed the bug in the code, found the final position and rates:
Check details here.

  • Min:

1) Solve the snake problem in linux by using -fno-automatic option.
2) Wrote a note about the optics discussion with Jixie.

  • Pengjia:

1) Will looking to the low current data taken during Xgt2 to check noise of adc in BCM|BPM
2) Arne will test the tungsten colorimeter with heater some time next week
3) The ring buffer is working, will move on to read ADC and helicity signal, and TCPIP program which
will be used to communicated between the ring buffer and HRS DAQ

  • Jie:

1) Shown improved result. After optimizing the fitting ranges, the variation of data to tosca reduce to 3%,
and the position offsets are all within 1 cm. Check | this for details.

8/3/2011: Present: Karl, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Jie

  • Karl:

1) Organized student go to UVA to participant the target cool down

  • Jixie:

1) The detector response function is ready in the Geant4 simulation program.
| Energies deposited by elas proton
| Hits in neutron simulation
| Total energy deposited by neutron. (Please note that the top panel is still for the 2nd plane, not the 1st plane.)
The energy deposited into the 2nd plane indirectly from the neutron is about 188 MeV per 100K 2.3 GeV electrons
or 160 ns with 100 nA beam current. It turns out we must have the neutron shielding!

2) To shield the neutron, 20 cm thick plastic (Polyethylene) can block 80~85% of the neutron flux.
Check detail here: [2]

3) Third arm detector design: Al confirm that we can put 20 cm thick plastic shielding.
The detector will be located 70 degrees, 2.1 meter away from the target. The SC plane size is 6'X 24',
with rotation by the vector (r=1, theta=70, phi=0) about 36 degrees (for 5T target field) or 18
degrees(for 2.5T target field). The 60 degrees of rotation about Y axis is not necessary since the shielding
for neutron is in place. The first layer of SC will be 2cm, and the 2nd layer will be 5 cm or 2 inches.
We need to find 2cm scintillator. The center position for each beam energies are the following:
1.159 Horizontal_offset = 6 cm, Vertical offset = 0 cm OR Horizontal_offset = 0 cm, Vertical offset = 18 cm
1.706 Horizontal_offset = 0 cm, Vertical offset = -21 cm
2.257 Horizontal_offset = 0 cm, Vertical offset = -15 cm
The position can allow 1~2 cm off, and the angle can allow 2 degrees off.
4) Have already inform Al with this design.

  • Chao:

1) Ran Geant4 simulation for the 3rd arm. Verified the rotation and position.
2) Recalculate the rates. It will take about 14, 10, 7 hours to measure Pb*Pt to 5% uncertainty with 1.2,
1.7 and 2.3 GeV beam. If we increase the SC wider it will shorten the time for 1.2 GeV but longer the time for
the others due the the signal to background noise get worse. We still need to optimize the design.

  • Ryan:

1) Working on trigger on S1m
2) Looked in the Y distribution of S0, it is about 15 cm, it seems ok for acceptance. | Figure 1 | Figure 2
3) Got the timing module working after replacing the broken cables. Bob suggested to unplug HRS cable and reconnect them.
4) Will work on the HOWTO wiki pages

  • Toby:

1) Checked the probe with known field in the magnetic group with Jixie, Chao and Jie. Both the 3-axis probe and
the axial probe seems within 1% accuracy. But we did not check the variance of the axial probe in rotation.
Plan to do this in UVA.
2) Determined the current ratio to be around 1.0. Jixie suggested to check again.

  • Jie:

1) Improved the field analysis result. He analysis the data X_table=44 or X_table=46, which is most closed to the z axis.
The new current ratio is 1.151, the position offsets are Xoff~=1.2 cm, Yoff=-0.5 cm, Zoff=0.4cm. Rotation and Xoff is not
sensitive at all in this data set because the field is almost flat when x is closed to 0.
Check the detail here: http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/fieldmap.pdf
2) Will use large X data to fit for rotation and Xoff.

  • Min:

1) Tried to pull fortran routines from cern packages. But too many to pull! Jixie suggested stop doing this.

  • Pengjia:

1) Successfully build the ring buffer to store BCM|BPM signal on HAPPEX DAQ
2) Will post the target connection diagram which can help to understand the target cool down. Check Elog entry 124
for detail https://hallaweb.jlab.org/dvcslog/g2p/124


7/27/2011: Present: Karl, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Jie

  • Jixie:

1)Neutron flux simulation.| details
There will be about 1.3~1.5 neutrons for each 2.3 GeV electron hitting the local dump.
For 6'x24' 3rd arm detector located at 70 degrees and 2.1 meters away from the target,
there will be about 0.0012 neutrons per 2.3 GeV electron. If converted to rates,
it will be about 800 MHz @ 100 nA beam current. This result has been confirm by a FLUKA program ran
by Lorenzo Zana (who is checking the radiation for PREX2).
Jixie will work on shielding the neutron. 2)Working on third arm simulation. |details
If rotated the 3rd arm by Y axis with 60 degrees (the the SC plane will be 10 degrees with
respected to X axis), we can have 3 advantages:
A)reduce the neutron flux by a factor of 5 (=sin(70deg)/sin(10deg))
B)do not need to cut the scintillator plane
C)effective thickness doubled and will have better ability to cut ADC for triggers. (need to simulate ...)
But it require more space in the target platform. Need to check with Al

3)Can not understand how the neutron will affect the 3rd arm trigger without the detector response
simulation. Jixie will add detector response into the Geant4 simulation.

  • Chao:

1) Working with Jixie on the 3rd arm simulation. Confirm the rotation angles and tried to find
the best positions for each beam energies.
2) Recalculated the rate for the 3rd arm.

  • Jie:

1) Tried to improve the analysis on the target field

  • Min:

1) Checked the self consistency of the HRS transportation packages.
2) The SNAKE works only in SunOS but not. MUDIFI works on jlabl2 but not on jlabs3. It was assumed to
be the cernlib problem. Karl suggested to pull the needed fortran routines out of cern packages and
build a stand-alone snake program.

  • Mellisa:

1) Finished checking the Cherencov.
2) Will move on to check the ADC signal of pre-shower and shower.

  • Ryan:

1) Checking timing for L1A (Level 1 acceptance) 2) Working on the trigger on S1m

  • Toby:

1) Optimized the fitting range in the field analysis


7/20/2011: Present:Karl, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Alexandre, Jie Liu

  • Jixie:

1) The design of the 3rd arm:
A) We need to place the 3rd arm at 70 degrees, not 72. We also have to move the detector
from 1.5 meter to 2.1 meter such that the local dump itself could block some background.
B) | Figure 1 shows the hit positions on the SC plane. The distribution look like a rotated strip.
In order to select a small range of theta, the SC need to be rotated to some angle.
C) | Figure 2 and | Figure 3 show the hit position for protons within and out of the theta range.
Please note that these protons are generated in a flat distribution of theta and Energy.
they are not elastic proton. Jixie will run with elastic proton again to check the rotation.
D) We might need to cut the SC from 12 inches width to 6 inches.
E) JP mentioned that it might help if the SC plane be rotated about Y axis by 70 degrees.
With this rotation the whole SC will have minimum cross section area facing the local dump.
2) Still working on neutron flux simulation.

  • Chao:

1) Simulate the 3rd arm detector located at various distance from the target (1.5, 1.75,2.0, 2.25 meter).
The detector size in the simulation is 6' x 24'. According to his result the dilution factor is about 17%
and the total time to accumulate 5% accuracy data is about 9 hours.

  • Min:

1) Check the no target field HRS transportation code

  • Pengjia:

1) learning the HAPPEX DAQ

  • Toby:

1) Show field analysis result on the can surface data set. After improve, the variation of measured field
to the map are within 1%. But the position offsets are still in 2 cm level. This analysis used only point A
position to calibrate all the data set, which leaves room for further improve. Jixie ask Toby to check
the code carefully.

  • Jie:

1) Show field map analysis. His result does not agree with Toby's.

  • Ryan:

1) Working on mapping the HRS HV. Finish ROC3 and ROC4. Check Elog entry 122 for detail:
https://hallaweb.jlab.org/dvcslog/g2p/121
2) Will work on DAQ with Alex
3) Will check PMT signal for S1 and S2m

  • Mellisa:

1) Working of the safety documents which is drawn from SANE group.
2) Checking the Cherencov, found the ADC for 1 photon-electron, but this result still need to be improved.

7/13/2011: Present:Jian-ping, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Alexandre, Jie Liu, Karl

  • Mellisa:

1) Continue checking the Cherencov detector. Applied geometry cut to the ADC. She need to find out
the ADC value that 1 PHE corresponding to. Check her plots in the Elog, Item 120:
https://hallaweb.jlab.org/dvcslog/g2p/120

  • Toby:

1) Showed the preliminary result for the field map analysis with the can surface data set. Most data
points are within 6% variation. But the position offsets are as large as 2 cm.

  • Jie:

1) Showed his result of the field map analysis. Most data points are with 10% variation to the
TOSCA map. Jie's result does not agree with Toby's in position and current ratio. Both of them are
requested to check their results more carefully.

  • Pengjia:

1) Tried to build ring buffer in HAPPEX DAQ. Will do the tungsten calorimeter calibration in August.

  • Ryan:

1)Looked into the HV for HRS
2)Finish the splitter box. Check Elog entry 121 for detail: https://hallaweb.jlab.org/dvcslog/g2p/121

  • Chao:

1) Tried to learn and run the Geant4 simulation for the 3rd arm.

  • Jixie:

1) Looking into the neutron background data provided by Pavel. 2) Designing the 3rd arm.

7/6/2011: Present: Jian-ping, Kalyan, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Alexandre, Jie Liu

  • JP:

1) Discussed the run plan with QWEAK group, ask for 12 days for 1.7 GeV. Not be granted yet.
Currently Hall C allow only 5 days, or If they are down then we can take the time for 1.7 GeV.
The plan is still under discussion.
2) If Hall B is not available, we need to be able to run 1.2 GeV. We should be very flexible and ready for changes.
3) Karl has the readiness review available. Everyone is encouraged to read and comment.
4) JP will leave from 7/22 to 8/17. Kaylan will leave to India from 7/8 to 7/29.
Alex will on vacation from 7/23 to 8/11. Karl will be on site from 7/11.

  • Min:

1) Just back from the summer school. Will continue working on the HRS package issues.

  • Chao:

1) Taking the detector geometry into account, recalculated the background of the 3rd arm using the epc code.
2) Discuss the 3rd arm design: 12 inch width will accept +/-4 degrees in theta. With such a wide
range it will take about 16 hours to measure Pb*Pt to 5% accuracy. It is too long ...
3) Finish the target field measurement with Jixie and Toby.

  • Pengjia:

1)Leaning HAPPEX DAQ, will use it for BCM and BPM
2)will do calorimeter test. The tungsten calorimeter will eventually used to calibrate BCM.
3)Learning how the Harp work and how to use it to calibrating BPM.

  • Toby:

1) Finish Target filed mapping with Jixie and Chao.
2) Working on analyzing the field mapping data.

  • Ryan:

1) Working on Left HRS trigger
2) Will check the material of the target with Josh

  • Mellisa:

1) Checking the Cherencov detector in HRS. Tried to find how many photon-electron (PHE) each PMT has
in the Xgt2 data set. She need to apply the geometry cut and try again.

  • Jie:

1) Analyzing the filed measurement data.

  • Jixie:

1) Just Finished the field measurement with help from Chao and Toby. Pengjia and Jie also provide appreciable help.
2) Measured the field in 2 ways. One is measuring the field on the can surface with an axial probe (borrowed
from Josh) fixed in a aluminum block.
http://www.jlab.org/~jixie/HallA/meeting/FieldMeasurement/IMG_0804.JPG
Another is measuring the filed with a 3-axis probe on the translation table.
http://www.jlab.org/~jixie/HallA/meeting/FieldMeasurement/IMG_0800.JPG
The survey group came to the target lab and survey some positions. Just got the survey data yesterday.
Jie and Toby are working on analyzing the field map measurement. Jie is focus on translation table data set
and Toby is working of the can surface data.
3) Talk to Pavel in the Rad. Con. group for the neutron background simulation. Pavel will provide
the neutron distribution and model information such that Jixie will be able to work on radiation calculation.

6/22/2011: Present: Kalyan, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Alexandre, Jie Liu

  • Toby:

1) Tested 4 cables for the slow raster with Ryan
2) Worked with Chao and Jixie to prepare to measure the target field

  • Ryan:

1) Continue working on the HRS trigger

  • Melissa:

1) Replaying xgt2 data. Looking at the pedestal of adc to find out if there are dead channels
2) Updating the safety document for g2p based on the one used in SANE experiment

  • Chao:

1) Preparing a computer in the hall for the DAQ of the 3rd arm 2) Preparing for the target field measurement


  • Pengjia:

1) Continue working on the remote control program for the function generator

  • Kalyan:

1) Continue designing the 3rd arm
2) Got confirmed from Al that 3rd arm can not be used in GEP

  • Jixie:

1) Learning the optics from Nilanga, will meet with Vince to discuss the optics plan
2) Tried to test the magnetize effect of the translation table. Replaced some steel bolts and nuts
with plastic ones. Toby and Chao will make a coil to test the stainless steel.
3) Running simulation to get local beam dump opening for Al. But the HRS transportation routines from Min do not work.

Minutes_Jan2011_to_June_2011

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