Difference between revisions of "Compton"

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= Spring 2016 Compton =
+
== The Hall A Compton ==
  
 
The Compton polarimeter is used to (non-invasively) monitor polarization of the incoming electron beam.  
 
The Compton polarimeter is used to (non-invasively) monitor polarization of the incoming electron beam.  
Line 10: Line 10:
 
<!-- Last edit on {{REVISIONYEAR}} {{REVISIONMONTH}} {{REVISIONDAY2}}, by {{REVISIONUSER}} -->
 
<!-- Last edit on {{REVISIONYEAR}} {{REVISIONMONTH}} {{REVISIONDAY2}}, by {{REVISIONUSER}} -->
  
== Operation Guide ==
+
== Shift Workers' Operation Guide ==
  
Instructions for shift workers to run Compton.
+
Start a Compton run every two hours.
 +
 
 +
The Compton DAQ is located in the back room in the Counting House. All commands are done from compton@compton.  
 +
 
 +
If CODA is not already running:
 +
 
 +
: Kill CODA first, then start it up again:
 +
 
 +
    $ kcoda
 +
    $ startcoda
  
# '''Pre-check:'''
 
## HV on/off? -> [[Compton#High Voltage Controls]]
 
## [Experts only]: Correct parameters for run in ''integratingDAQ.flags'' and ''compton.params''?
 
# '''Start CODA:'''
 
: In compton@compton: ''startcoda''
 
 
: A few new Terminal windows and a GUI pop up.  
 
: A few new Terminal windows and a GUI pop up.  
 
:: [[Image:LT CODAgui.png|800px]]
 
:: [[Image:LT CODAgui.png|800px]]
Line 27: Line 31:
 
:# In bottom, click on "Download" button
 
:# In bottom, click on "Download" button
 
:# In bottom, click on "Prestart" button
 
:# In bottom, click on "Prestart" button
:# When ready to start run, click "Start" button. Most runs are typically ~2 hours.
+
:# When ready to start run, click "Start" button. Typical run duration: 2 hours. Type in any Start Of Run comments in the box. Click "OK" (even if you left comments blank!).
:# When ready to stop run, click "End" button
+
:# When ready to stop run, click "End" button. Type in any End Of Run comments in the box. Click "OK" (even if you left comments blank!).
: To close CODA and kill all related processes, type ''kcoda''.
+
# '''Run Compton analysis:'''
+
## In compton@compton: ''cd /home/franklin/CompMon/''
+
## Run analysis software: ''compmon [insert run number here, no brackets]''
+
## Open ROOT: ''root lnkCompMon.output''
+
## Run desired C script located in CompMon directory: ''.x [insert scriptname here, no brackets]''. Currently, we are interested in seeing the raw asymmetry, so run ''.x plotAsymSpectrum.C''.
+
## Sip and admire.
+
  
 +
== Information for Compton Experts ==
 +
=== Troubleshooting ===
 +
# HV on/off? -> [[Compton#High Voltage Controls]]
 +
# Rebooting components: [[Compton Reboot]]
 +
# [Experts only]: Correct parameters for run in ''integratingDAQ.flags'' and ''compton.params''
  
<!--  <small>''Last edit: ~~~~''</small> -->
+
=== Collimator Systems ===
  
== Hardware ==
+
[[File:Jaws_positions.PNG|thumb|300px|What the jaws look like when placed at their lowest position, as seen on comptcam2. To view this camera follow [http://comptcam2.jlab.org this link] and login with compton credentials.]]
 +
* Primary Lead Collimator
 +
** Presently left fully open at 20 mm diameter.
 +
** This is a 10 cm long collimator with inserts which can reduce aperture down to 10 mm or 5 mm in diameter.
 +
* Synchrotron Shields
 +
** For PREX-II a single 0.25 mm lead foil (painted) is taped to the front of the photon detector.
 +
* Compton Jaws
 +
** Remote access for experts can be found at [http://compjaws.jlab.org]
 +
** Note, for the duration of the PREX-II running period, the Compton Tungsten Collimator System ("Compton Jaws") will not be used. It should be left it is's parked position of:
 +
    aperture =   1.5 mm
 +
    y center = -46.0 mm
  
Electronics, etc.
+
=== Detector Positioning System ===
  
 +
* Centering Beam & Photon Detector
 +
** Refer to section [[Compton Photon Detector Centering Procedure]] for more info.
 +
* For controls, troubleshooting: [[Compton Photon Detector]]
 +
* Home position of photon detector table:
 +
{| class="wikitable"
 +
! Date
 +
! X [mm]
 +
! Y [mm]
 +
! Comment
 +
|-
 +
| 2019-06-17
 +
| 70
 +
| 33.5
 +
| Visually Centered
 +
<!--
 +
|-
 +
| 2019-XX-XX
 +
| XX
 +
| XX
 +
| XX
 +
-->
 +
|}
  
=== Photon Detector Table ===
+
=== Cameras ===
 
+
* [http://comptcam1.jlab.org ComptCam1]: Detector Table
For controls, troubleshooting: [[Compton Photon Detector]]
+
* [http://comptcam2.jlab.org ComptCam2]: Tungsten Jaws
 
+
  
 
=== High Voltage Controls ===
 
=== High Voltage Controls ===
 +
* [[HV Control GUI]]
 +
** GUI can only be accessed once per person. We share this GUI with Moller Polarimeter.
  
Know the HV channel and navigate to the GUI: [[HV Control GUI]]
+
=== LED System (Linearity Measurement System) ===
 +
* Will add info on MiniMegan soon
  
 +
'''Taking an LED run:'''
  
<!--  <small>''Last edit: [[User:Lthorne|Lthorne]] 16:35, 4 February 2016 (UTC)''</small> -->
+
# Find parameter file GUI:
 +
    $ cd /home/compton/franklin/
 +
    $ ComptonConfig
 +
# Click "Pulser On, Pulser Trigger" on parameter file. Click "Apply", then "Done" to close GUI.
 +
# Go to CODA. Start a new run to apply the settings. (This does not need to be a long run. You may end it immediately.)
 +
# Start your LED run.
 +
# ''When you go back to normal Compton runs: don't forget to turn the pulser off and do a short run to update the parameter file settings!''
  
 
=== Laser System ===
 
=== Laser System ===
  
 
[[Real time o-scope signals]]
 
[[Real time o-scope signals]]
 +
 +
[[Cavity lock camera]]
  
 
[[Make sure laser flipping is on]]
 
[[Make sure laser flipping is on]]
Line 74: Line 119:
  
 
Relevant files, scripts, etc.
 
Relevant files, scripts, etc.
 +
 +
'''Run Compton analysis:'''
 +
 +
In compton@compton:
 +
 +
    $ cd /home/compton/online/CompMon
 +
 +
Run analysis software:
 +
 +
    $ ./compmon <run number, no brackets>
 +
 +
Open ROOT:
 +
 +
    $ root -l /data/cmuwork/rootfiles/Fall2016/compmon_<run number, no brackets>.root
 +
 +
Run desired C script located in CompMon directory.
 +
 +
 +
'''Some useful analysis scripts:'''
 +
* '''For PREX we should use: ''' <code>/home/compton/online/CompMon/dataQualityCheck.C</code> '''as our online macro!'''
 +
** As of now the way to run it is to navigate to the directory with the file and then running with <code>root -l dataQualityCheck.C\(<run number>,<tests flag>\)</code> We're looking into adding a simplified interface in the near future.
 +
The following macros were maintained by people who no longer work on the compton so use with caution:
 +
* /home/compton/lthorne/CompMon/plotAsymSpectrum.C: Quick and dirty view of asymmetry histograms, cavity and BCM limits.
 +
* /home/compton/lthorne/CompMon/buildQuartets.C and buildQuartetsPlot.C: For constructing multi-run asymmetry plots.
 +
** Run instructions are given in the comments at the beginning fo the file.
 +
* /home/compton/lthorne/CompMon/BCMCal/calibration<runNumber>,C: BCM calibration scripts for specific runs.
 +
* /home/compton/lthorne/CompMon/plotAccQuartets.C: plots sum, difference histograms for beam off, laser on, laser off for Acc0, Acc4.
 +
* /home/compton/franklin/CompMon/plotPulser.C: peek at DAQ pulser channels, including info on 'variable' and 'delta' for channel 13.
 +
 +
 +
'''Link to list of good Compton runs:'''
 +
 +
List of runs with comments, so know which ones were not junk.
 +
 +
DVCS Google Docs: [https://docs.google.com/spreadsheets/d/1gSmgOaJW2azUDhhULDroP4eSpFxkn88YoFsQYNUVS1E/edit?usp=sharing Runlist] (Email Juan Carlos if you want to granted write permission)
 +
PREX-CREX Google Docs: [https://docs.google.com/spreadsheets/d/13SW_Ya0zV5NDWxlS9A5FQ6b9YzpJw2fRNshcWm-noRA/edit?usp=sharing Runlist]  (Email Juan Carlos if you want to granted write permission)
 +
 +
 +
 +
<!--  <small>''Last edit: ~~~~''</small> -->
  
  
Line 89: Line 174:
 
<!--  <small>''Last edit: [[User:Lthorne|Lthorne]] 16:35, 4 February 2016 (UTC)''</small> -->
 
<!--  <small>''Last edit: [[User:Lthorne|Lthorne]] 16:35, 4 February 2016 (UTC)''</small> -->
  
= Compton Meetings =
+
== PREX-II/CREX Compton Analysis ==
  
See last list entry for most recent meeting.
+
We've reworked the analysis to streamline finding the most important plots. We've adopted the analysis GUI used by panguin and other online monitors for Hall A experiments. To run, follow the steps below.
  
* [[Friday, December 7, 2012 11am EST - Compton]]
+
=== Online Analysis Steps and Checks ===
* [[Monday, January 14, 2013 1pm EST - Compton]]
+
 
* [[Tuesday, February 12, 2013 3pm EST - Compton]]
+
# Using the directions at the top of the page, open CODA and start a run.
* [[Thursday, March 28, 2013 1pm EST - Compton]]
+
# Open a terminal and login using <code>ssh -Y compton@compton.jlab.org</code>
* [[Wednesday, May 1, 2013 2pm EST - Compton]]
+
# Enter command <code>gocompton</code>
* [[Thursday, September 26, 2013 2pm EST - Compton]]
+
# First run compmon to analyze the run. To this use command <code>./compmon.sh -r <run number></code>
* [[Thursday, November 14, 2013 2pm EST - Compton]]
+
# Once the run is finished analyzing and errors are logged, enter <code>source online.csh -r <run number></code>. This will create the plots in the GUI window.
* [[Tuesday, December 10, 2013 11am EST - Compton]]
+
# Look at the plots in the following tabs:
* [[Thursday, February 27, 2014 2:30pm EST - Compton]]
+
#* Snapshots: This window has one plot of snapshot peak height vs sum. Plot should look starkly linear. Plot also has the percentage of snapshots that pass an arbitrary selection criteria. I find healthy runs have about 80% of snapshots pass.
* [[Friday, April 4, 2014 2:00pm EDT - Compton]]
+
#* Spectra: Plots compton spectrum broken down by beam and laser state. Is the compton edge where we expect it to be? Are Brem events low when beam or laser is off?
* [[Thursday, May 21, 2015, 11:00am EDT - Compton]]
+
#* Acc0: Plots of accumulator 0. Are they gaussian? Does the mean of the beam ON, laser ON plot differ from all the others?
* [[Thursday, June 4, 2015, 11:00am EDT - Compton]]
+
#* Acc0 vs Time: Plots of accumulator 0 value vs mps number. Are the accumulator values drifting significantly with time?Are beam trips readily noticeable?
* [[Thursday, July 2, 2015, 11:00am EDT - Compton]]
+
#* Asym and Polarization: Includes plots of the quartet sums, differences and asymmetry. Do they all look roughly gaussian? Are there no double-peaking effects? Does the calculated polarization yield some reasonable value?
* [[Thursday, July 23, 2015, 11:00am EDT - Compton]]
+
#* Asyms vs Time: Plots of the above vs time. Is there any significant drift in any of the quantities vs time?
* [[Thursday, August 6, 2015, 11:00am EDT - Compton]]
+
#* Asym Spectrum: '''As of 2019-07-31 this plot is not working. Background subtraction needs to be more carefully refined.'''
* [[Thursday, September 3, 2015, 11:00am EDT - Compton]]
+
# Once you click "Exit GUI" the same plots will be generated and saved to the [http://hallaweb.jlab.org/parity/prex/onlinePlots/comptonPlots compton plots web page] for easy review.
* [[Thursday, September 17, 2015, 11:00am EDT - Compton]]
+
 
* [[Monday, September 28, 2015, 11:00am EDT - Compton]]
+
=== Making Custom Plots ===
* [[Monday, October 19, 2015, 11:00am EDT - Compton]]
+
There are macros which make other compton plots which have been useful in the past, but are not being maintained anymore. To be certain, you can make your own plots to slake your curiosity. The following is description of CompMon output, the branches, as well as certain variables which you may find useful.
* [[Monday, November 9, 2015, 11:00am EST - Compton]]
+
 
* [[Monday, November 23, 2015, 11:00am EST - Compton]]
+
* General Variables: These variables may be found stored in multiple trees and should come in handy:
* [[Monday, December 7, 2015, 11:00am EST - Compton]]
+
** helicityStateReported: 0 for negative, 1 for positive
* [[Monday, January 11, 2016, 11:00am EST - Compton]]
+
** laserState: 0 for right-hand polarization and laser on, 1 for left-hand polarization and laser on, 2 for right hand polarization and laser off, 3 for left hand polarization and laser off, 4 for unknown state
* [[Thursday, January 28, 2016, 10:00am EST - Compton]]
+
** beamState: 0 for beam off, 1 for beam on, 2 for unknown beam state.
* [[Thursday, February 11, 2016, 10:00am EST - Compton]]
+
** cavPowerCalibrated: laser cavity power
* [[Thursday, February 25, 2016, 10:00am EST - Compton]]
+
** bcm: calibrated BCM signal
* [[Thursday, March 10, 2016, 10:00am EST - Compton]]
+
* mpswise: A tree of data stored per MPS
* [[Thursday, March 31, 2016, 10:00am EDT - Compton]]
+
** mpsCoda: MPS number
* [[Thursday, April 21, 2016, 10:00am EDT - Compton]]
+
** Acc#: Accumulator total for number #
* [[Thursday, May 5, 2016, 10:00am EDT - Compton]]
+
** NAcc#: Number of accumulator samples per MPS for accumulator number #
 +
** numTriggers: Number of triggered sums in current MPS
 +
* triggerwise: A tree of variables stored per trigger
 +
** sum: Total sum of trigger
 +
** sumIsRandom: 0 if sum is real, 1 if it is random
 +
* quartetwise: A tree of variables stored per quartet
 +
** PosHelAcc#: Sum of accumulator number # for positive helicity states in the quartet
 +
** PosHelNSamples#: Number of samples for accumulator number # for positive helicity states in the quartet
 +
** NegHelAcc#: Sum of accumulator number # for negative helicity states in the quartet
 +
** NegHelNSamples#: Number of samples for accumulator number # for negative helicity states in the quartet
 +
** quartetReportedHelicityPattern: Two different values, one for each valid quartet pattern
 +
* snapshots: A list of variables and snapshot readouts for each snapshot taken
 +
** numSamples: Number of samples in snapshots
 +
** snap: An array variable with numSamples entries that details the fADC readout of the snapshot
 +
* pulserwise: A tree of variables stored per pulser cycle. (SHOULD ONLY BE NEEDED BY EXPERTS)
 +
* runwise: A tree of variables stored per run. This tree only has one entry per leaf, and details info about pedestals.
 +
* epicswise: A tree of variables taken per EPICS event. These variables are also stored in other trees, so they can be accessed from there.
 +
 
 +
This is in addition to the inbuilt histograms produced in every CompMon output file. This should be more than enough to diagnose any compton DAQ problems.
 +
 
 +
== Compton Meetings ==
 +
 
 +
See last list entry for most recent meeting.
 +
* [[Meetings before 2014]]
 +
* [[2014 Meetings]]
 +
* [[2015 Meetings]]
 +
* [[2016 Meetings]]
 +
* [[2017 Meetings]]
 +
* [[Monday, February 12, 2018, 11:00 am EST - Compton Electron Detector]]
 +
* [[Monday, February 19, 2018, 11:00 am EST - Compton Electron Detector]]
 +
* [[Thursday, May 10, 2018, 10:00 am EDT - Compton]]
 +
* [[Thursday, May 24, 2018, 10:00 am EDT - Compton]]
 +
* [[Thursday, June 14, 2018, 10:00 am EDT - Compton]]
 +
* [[Thursday, July 5, 2018, 10:00 am EDT - Compton]]
 +
* [[Thursday, July 19, 2018, 10:00 am EDT - Compton]]
 +
* [[Thursday, August 9, 2018, 10:00 am EDT - Compton]]
 +
* [[Thursday, August 23, 2018, 10:00 am EDT - Compton]]
 +
* [[Thursday, September 6, 2018, 10:00 am EDT - Compton]]
 +
* [[Wednesday, September 19, 2018, 11:00 am EDT - Compton]]
 +
* [[Wednesday, October 17, 2018, 11:00 am EDT - Compton]]
 +
* [[Wednesday, November 7, 2018, 11:00 am EST - Compton]]
 +
* [[Wednesday, November 28, 2018, 11:00 am EST - Compton]]
 +
* [[Wednesday, December 12, 2018, 11:00 am EST - Compton]]
 +
* [[Wednesday, January 9, 2019, 11:00 am EST - Compton]]
 +
* [[Wednesday, January 23, 2019, 11:00 am EST - Compton]]
 +
* [[Wednesday, February 6, 2019, 11:00 am EST - Compton]]
 +
* [[Wednesday, February 27, 2019, 11:30 am EST - Electron Detector]]
 +
* [[Wednesday, March 20, 2019, 11:00 am EST]]
 +
* [[Wednesday, April 17, 2019, 11:00 am EDT]]
 +
* [[Wednesday, May 1, 2019, 11:00 am EDT]]
 +
* [[Wednesday, May 8, 2019, 11:00 am EDT]]
 +
* [[Wednesday, May 22, 2019, 11:00 am EDT]]
 +
* [[Wednesday, May 29, 2019, 11:00 am EDT]]
 +
* [[Wednesday, June 5, 2019, 11:00 am EDT]]
 +
* [[Wednesday, June 12, 2019, 2:30 pm EDT]]
 +
* [[Wednesday, August 14, 2019, 11:00 am EDT]]
  
= Current Compton Experts =
+
== Current Compton Experts ==
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 138: Line 278:
 
|-
 
|-
 
| Ciprian Gal  
 
| Ciprian Gal  
| x6235
+
| x5324
 +
|-
 +
| Juan Carlos Cornejo (Photon Detector)
 +
| x5282
 
|}
 
|}
  
= Expert Information =
+
== Expert Information ==
 
For expert monitoring and troubleshooting information please visit [[Compton Expert Information]].
 
For expert monitoring and troubleshooting information please visit [[Compton Expert Information]].
  
= Old Compton page (pre-Spring 2016) =
+
== Analyzer ==
 +
Code can be found on github: https://github.com/JeffersonLab/HallA_CompMon
 +
JC says:
 +
The Makefile is ancient (since it has to work on old systems too) but there is an easy "fix".  In the src/config.d directory, create a file similar to cornejo_compton_jlab.conf but modify the paths respectively.
 +
Then run ./config config.d/<your_config_file>
 +
It will update the silly Makefile accordingly
 +
 
 +
Some old data and examples can be found on
 +
/w/halla-scifs17exp/compton/disk1/data/examples
 +
 
 +
== Old Compton page (pre-Spring 2016) ==
  
 
See [[Pre-Spring 2016 Compton]]
 
See [[Pre-Spring 2016 Compton]]

Latest revision as of 09:50, 13 August 2019

The Hall A Compton

The Compton polarimeter is used to (non-invasively) monitor polarization of the incoming electron beam. It has three major components: an optics table with a laser that can lock to a Fabry-Perot cavity, an electron detector, and a photon detector to count scattered electrons and photons, respectively.

Last edit: LThorne 02:08, 24 February 2016 (UTC)


Shift Workers' Operation Guide

Start a Compton run every two hours.

The Compton DAQ is located in the back room in the Counting House. All commands are done from compton@compton.

If CODA is not already running:

Kill CODA first, then start it up again:
   $ kcoda
   $ startcoda
A few new Terminal windows and a GUI pop up.
LT CODAgui.png
Let "top" refer to the bar with named menu options near the top of the GUI (ex: Platform, Sessions, etc). Let "bottom" refer to the bar below "top" that contains a line of buttons (hover over them to reveal their labels; starting with "Configuration" on the left).
  1. In top, select: Platform > Connect
  2. In bottom, click on "Configuration" button.
    • If configuration listed in the "Run Parameters" box is not FADC_prod: in top, select Configurations > Cool and change it to FADC_Prod.
  3. In bottom, click on "Download" button
  4. In bottom, click on "Prestart" button
  5. When ready to start run, click "Start" button. Typical run duration: 2 hours. Type in any Start Of Run comments in the box. Click "OK" (even if you left comments blank!).
  6. When ready to stop run, click "End" button. Type in any End Of Run comments in the box. Click "OK" (even if you left comments blank!).

Information for Compton Experts

Troubleshooting

  1. HV on/off? -> Compton#High Voltage Controls
  2. Rebooting components: Compton Reboot
  3. [Experts only]: Correct parameters for run in integratingDAQ.flags and compton.params

Collimator Systems

What the jaws look like when placed at their lowest position, as seen on comptcam2. To view this camera follow this link and login with compton credentials.
  • Primary Lead Collimator
    • Presently left fully open at 20 mm diameter.
    • This is a 10 cm long collimator with inserts which can reduce aperture down to 10 mm or 5 mm in diameter.
  • Synchrotron Shields
    • For PREX-II a single 0.25 mm lead foil (painted) is taped to the front of the photon detector.
  • Compton Jaws
    • Remote access for experts can be found at [1]
    • Note, for the duration of the PREX-II running period, the Compton Tungsten Collimator System ("Compton Jaws") will not be used. It should be left it is's parked position of:
   aperture =   1.5 mm
   y center = -46.0 mm

Detector Positioning System

Date X [mm] Y [mm] Comment
2019-06-17 70 33.5 Visually Centered

Cameras

High Voltage Controls

  • HV Control GUI
    • GUI can only be accessed once per person. We share this GUI with Moller Polarimeter.

LED System (Linearity Measurement System)

  • Will add info on MiniMegan soon

Taking an LED run:

  1. Find parameter file GUI:
   $ cd /home/compton/franklin/
   $ ComptonConfig
  1. Click "Pulser On, Pulser Trigger" on parameter file. Click "Apply", then "Done" to close GUI.
  2. Go to CODA. Start a new run to apply the settings. (This does not need to be a long run. You may end it immediately.)
  3. Start your LED run.
  4. When you go back to normal Compton runs: don't forget to turn the pulser off and do a short run to update the parameter file settings!

Laser System

Real time o-scope signals

Cavity lock camera

Make sure laser flipping is on

Turning off the laser

IOC reboot

Accessing the laser hutch in the hall

Laser and Locking troubleshooting

Software & Data Analysis

Relevant files, scripts, etc.

Run Compton analysis:

In compton@compton:

   $ cd /home/compton/online/CompMon

Run analysis software:

   $ ./compmon <run number, no brackets>

Open ROOT:

   $ root -l /data/cmuwork/rootfiles/Fall2016/compmon_<run number, no brackets>.root

Run desired C script located in CompMon directory.


Some useful analysis scripts:

  • For PREX we should use: /home/compton/online/CompMon/dataQualityCheck.C as our online macro!
    • As of now the way to run it is to navigate to the directory with the file and then running with root -l dataQualityCheck.C\(<run number>,<tests flag>\) We're looking into adding a simplified interface in the near future.

The following macros were maintained by people who no longer work on the compton so use with caution:

  • /home/compton/lthorne/CompMon/plotAsymSpectrum.C: Quick and dirty view of asymmetry histograms, cavity and BCM limits.
  • /home/compton/lthorne/CompMon/buildQuartets.C and buildQuartetsPlot.C: For constructing multi-run asymmetry plots.
    • Run instructions are given in the comments at the beginning fo the file.
  • /home/compton/lthorne/CompMon/BCMCal/calibration<runNumber>,C: BCM calibration scripts for specific runs.
  • /home/compton/lthorne/CompMon/plotAccQuartets.C: plots sum, difference histograms for beam off, laser on, laser off for Acc0, Acc4.
  • /home/compton/franklin/CompMon/plotPulser.C: peek at DAQ pulser channels, including info on 'variable' and 'delta' for channel 13.


Link to list of good Compton runs:

List of runs with comments, so know which ones were not junk.

DVCS Google Docs: Runlist (Email Juan Carlos if you want to granted write permission) PREX-CREX Google Docs: Runlist (Email Juan Carlos if you want to granted write permission)



Helicity controls

From within NewTools controls (see first few steps in Compton Photon Detector Compton GUI section):

  1. On far right of JTabs menu, there are "master" controls. Find and click on Tools Screen.
  2. Go to the helicity controls. (The default is delayed, so be careful of this.)

Current Scripts

As a brief check, run plotAsymSpectrum.C.

LTRun2565AsymNew.png


PREX-II/CREX Compton Analysis

We've reworked the analysis to streamline finding the most important plots. We've adopted the analysis GUI used by panguin and other online monitors for Hall A experiments. To run, follow the steps below.

Online Analysis Steps and Checks

  1. Using the directions at the top of the page, open CODA and start a run.
  2. Open a terminal and login using ssh -Y compton@compton.jlab.org
  3. Enter command gocompton
  4. First run compmon to analyze the run. To this use command ./compmon.sh -r <run number>
  5. Once the run is finished analyzing and errors are logged, enter source online.csh -r <run number>. This will create the plots in the GUI window.
  6. Look at the plots in the following tabs:
    • Snapshots: This window has one plot of snapshot peak height vs sum. Plot should look starkly linear. Plot also has the percentage of snapshots that pass an arbitrary selection criteria. I find healthy runs have about 80% of snapshots pass.
    • Spectra: Plots compton spectrum broken down by beam and laser state. Is the compton edge where we expect it to be? Are Brem events low when beam or laser is off?
    • Acc0: Plots of accumulator 0. Are they gaussian? Does the mean of the beam ON, laser ON plot differ from all the others?
    • Acc0 vs Time: Plots of accumulator 0 value vs mps number. Are the accumulator values drifting significantly with time?Are beam trips readily noticeable?
    • Asym and Polarization: Includes plots of the quartet sums, differences and asymmetry. Do they all look roughly gaussian? Are there no double-peaking effects? Does the calculated polarization yield some reasonable value?
    • Asyms vs Time: Plots of the above vs time. Is there any significant drift in any of the quantities vs time?
    • Asym Spectrum: As of 2019-07-31 this plot is not working. Background subtraction needs to be more carefully refined.
  7. Once you click "Exit GUI" the same plots will be generated and saved to the compton plots web page for easy review.

Making Custom Plots

There are macros which make other compton plots which have been useful in the past, but are not being maintained anymore. To be certain, you can make your own plots to slake your curiosity. The following is description of CompMon output, the branches, as well as certain variables which you may find useful.

  • General Variables: These variables may be found stored in multiple trees and should come in handy:
    • helicityStateReported: 0 for negative, 1 for positive
    • laserState: 0 for right-hand polarization and laser on, 1 for left-hand polarization and laser on, 2 for right hand polarization and laser off, 3 for left hand polarization and laser off, 4 for unknown state
    • beamState: 0 for beam off, 1 for beam on, 2 for unknown beam state.
    • cavPowerCalibrated: laser cavity power
    • bcm: calibrated BCM signal
  • mpswise: A tree of data stored per MPS
    • mpsCoda: MPS number
    • Acc#: Accumulator total for number #
    • NAcc#: Number of accumulator samples per MPS for accumulator number #
    • numTriggers: Number of triggered sums in current MPS
  • triggerwise: A tree of variables stored per trigger
    • sum: Total sum of trigger
    • sumIsRandom: 0 if sum is real, 1 if it is random
  • quartetwise: A tree of variables stored per quartet
    • PosHelAcc#: Sum of accumulator number # for positive helicity states in the quartet
    • PosHelNSamples#: Number of samples for accumulator number # for positive helicity states in the quartet
    • NegHelAcc#: Sum of accumulator number # for negative helicity states in the quartet
    • NegHelNSamples#: Number of samples for accumulator number # for negative helicity states in the quartet
    • quartetReportedHelicityPattern: Two different values, one for each valid quartet pattern
  • snapshots: A list of variables and snapshot readouts for each snapshot taken
    • numSamples: Number of samples in snapshots
    • snap: An array variable with numSamples entries that details the fADC readout of the snapshot
  • pulserwise: A tree of variables stored per pulser cycle. (SHOULD ONLY BE NEEDED BY EXPERTS)
  • runwise: A tree of variables stored per run. This tree only has one entry per leaf, and details info about pedestals.
  • epicswise: A tree of variables taken per EPICS event. These variables are also stored in other trees, so they can be accessed from there.

This is in addition to the inbuilt histograms produced in every CompMon output file. This should be more than enough to diagnose any compton DAQ problems.

Compton Meetings

See last list entry for most recent meeting.

Current Compton Experts

Expert Phone
Dave Gaskell x6092
Alexandre Camsonne x5064
Ciprian Gal x5324
Juan Carlos Cornejo (Photon Detector) x5282

Expert Information

For expert monitoring and troubleshooting information please visit Compton Expert Information.

Analyzer

Code can be found on github: https://github.com/JeffersonLab/HallA_CompMon JC says:

The Makefile is ancient (since it has to work on old systems too) but there is an easy "fix".  In the src/config.d directory, create a file similar to cornejo_compton_jlab.conf but modify the paths respectively. 
Then run ./config config.d/<your_config_file> 
It will update the silly Makefile accordingly

Some old data and examples can be found on

/w/halla-scifs17exp/compton/disk1/data/examples

Old Compton page (pre-Spring 2016)

See Pre-Spring 2016 Compton


Last edit on 2019 08 13, by Gaskelld