XEM analysis instructions

If you have any questions or comments, please email - cmorean@jlab.org, or call cell # on whiteboard

• We would like the detector check replay to be done on first 50,000 events of every run, and compare plots with the standard ones in the binder. In addition, we want physics replay to be done on every run in its entirety.
• Do not start the full analysis until after the run ends!
• The standard.kinematics file should update automatically. If you notice a dramatic change in plots, the background process may have terminated. See the appropriate section below.

• Shift leaders are asked to keep a running total of the number of e- events; This will help us better estimate when to move to the next setting.

TLDR - Quick Start

SHMS ANALYSIS

• ssh to cdaql1, cdaql3 is currently unavailable.
• go_analysis
• Do a 50k replay for each arm as soon as you get 50k events
• ./run_coin_shms.sh
• ./run_coin_shms.sh
  • Execute the SHMS 50k replay on the latest run

HMS ANALYSIS

• ssh to cdaql1, cdaql3 is currently unavailable.
• go_analysis
• Do a 50k replay for each arm as soon as you get 50k events
• ./run_coin_hms.sh
  • Execute the HMS 50k replay on the latest run

• Execute the main analysis script after the run is over
• ./run_xemCOIN.sh
  • Execute the main analysis script
  • Follow the prompts, provide the required arguments

Notes on the 50k Replay

• By default, the hms and shms 50k replay scripts process the first 50k events from the most recent .dat file
• You can run more events or process a different run number if needed by providing different arguments
• To process a different run number -
  • Provide a run number as an argument, for example, to process run 12384 through the HMS -
    • ./run_coin_hms.sh 12834
• To process more events -
  • Provide the run number and number of events you want to process, for example -
    • ./run_coin_hms.sh 12834 100000
  • Would process 100k events for run 12834 on the HMS
• When processing carbon hole runs, you may wish to run more than 50k events

Carbon Hole Runs

• See the instructions on the beam checkout page
• Broad instructions are included below
• Adjust the prescale settings accordingly, set a target rate of ~1kHz for the HMS and SHMS 3/4 triggers (PS1 and PS3)
  • The rates you'll see will depend heavily upon setting, the step above is just to get reasonable rates to disc
• Once the prescale values are set, start a run
• When you have 50-100k events, run a HMS and SHMS 50k
  • Check the HMS/SHMS Fast Raster page of the output plots, check the hole position. If it looks off, ask MCC to adjust the position.
  • You will need to stop and start a new run when they adjust the position
  • This may take some trial and error to correctly centre the beam
  • You can also try running more than 50k events in the replay if needed (see above)
  • More information is located here

Detailed Online Analysis Instructions

• The analysis instructions below assume that you are logged in as cdaq on cdaql2 and are in the folder /home/cdaq/hallc-online/hallc_replay_lt
• If are not logged into cdaql2 as cdaq, then from any HCDESK machine, open a terminal and do the following -
  • ssh cdaql2
    • cdaql1 and cdaql3 are also available, try not to use the same machine all the time
  • go_analysis
• This will setup the analysis environment and take you to /home/cdaq/hallc-online/hallc_replay_lt, do not type go_analysis as a means to return to that folder

Each new kinematic setting

• Every time you move to a new kinematic setting you must also adjust some things to get the analysis working
• You must edit the file standard.kinematics in the DBASE/COIN subdirectory to add the current kinematic information.
• Go to the last block in the file, leave a blank line and then copy and paste the block below itself, you must leave a blank line in between each kinematic setting
• An example of how this should look after you've pasted in the new block can be seen below -

• Edit the run number range of the two blocks, use 99999 if the run is ongoing
  • Remember to edit the run number range of the previous block too
• Next, enter the beam energy determined from the arc measurement, the target mass in amu (available at the top of the file), and the spectrometer angles from the TV.
  • The HMS angle (htheta) should be entered as negative and the SHMS angle (ptheta) should be entered as positive
• Next are the central momenta of the HMS and SHMS, followed by the mass of the particle each arm should detect (the leading letter indicates which arm: p = SHMS, h = HMS).
  • The momentum values should ALWAYS be entered as positive values, regardless of the spectrometer polarity
• Leave the helicity frequency as is
• The HMS and SHMS RF offsets are to centre the RF timing distributions
  • The SHMS offset should be chosen such that pions are centred at 2
• The eHadCoinTime_Offset should be chosen such that the coincidence time for pions is centred at 0
  • Don't worry about setting this precisely immediately, it can be corrected for in subsequent analysis trivially
• You can also add a comment line (start the comment line with a hash - #) before the run numbers to explain what the block is for
• An example of what this looks like when done correctly can be seen below -

After 50,000 events have been taken

• We run two scripts to check the detectors.
• Type ./run_coin_shms.sh to automatically replay the most recent run and launch the online replay GUI.
• Type ./run_coin_hms.sh to repeat the process for HMS detectors.
• For reference, all histos are saved in the HISTOGRAMS/Analysis/50k subdirectory. A copy of the scaler report is in REPORT_OUTPUT/Analysis/50k.
• Compare with the histograms in the golden run binder, make an elog entry if you notice any major differences
  • You should also make a log entry if you notice any consistent trends on the plots over your shift

After the run is over

• Once the run ends you need to execute an analysis script.
• The script is - run_pionLT.sh located in /home/cdaq/hallc_online/hallc_replay_lt (you should be in this folder already)
• This script requires three arguments -
  • Run number - This must be a positive integer, specify the run you want to analyse
  • Run type - You must enter one of - Prod - Lumi - HeePSing -HeePCoin - Optics , the argument is case sensitive
  • Target - You must enter one of - LH2 - LD2 - Dummy10cm - Carbon0p5 - Optics1 - Optics2 - CarbonHole , again, the argument is case sensitive
• The script will prompt you to re-enter the arguments if anything is not correct, hit ctrl+c at any time to exit the script
• Specify the run type and target as dictated by the run plan
• Depending upon the run type specified, the script will call the relevant analysis script, details on the individual scripts are provided in a separate section
  • run_pionLT.sh will print to screen the path of the script it is trying to execute
  • Generally, all of the scripts called will execute a replay, and then some subsequent analysis scripts
  • Once they complete, the script will fill the run list with relevant info, follow the onscreen prompts

XEM Production Script

Plots

When a production replay is complete it will output a pdf file to OUTPUT/Analysis/XEM, which contains the following:

Debugging

• For information on how to adjust the cuts, see here
  • Physics plots looking odd are likely due to timing cuts not being set correctly
• If there are warnings or prompts that files aren't being found, read them and check if they're true
  • For example if it complains /This/Is/My/Path/To/File.txt doesn't exist, just do - ll /This/Is/My/Path/To/File.txt

Debugging - General

If any of the plots look odd/not as described, you should -

• Double check that standard.kinematics has been updated and is CORRECT, verify that when you start the replay the values you THINK it is reading appear in the hcana initiation info dump. See the images below -

• Watch out for silly typos, e.g. gbeam rather than gpbeam.
• Note that standard.kinematics affects things you think it really shouldn't! If things look wrong this is absolutely the first thing you should check.
• Make sure you have the correct particles going into each spectrometer

You should not -

• Panic
• Start editing scripts and deleting things without knowing what you are adjusting
• Delete ANYTHING in the scripts without also leaving a comment explaining what you have deleted or changed