Analysis Expert

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Revision as of 09:18, 10 August 2020 by Cameronc (Talk | contribs) (Modes of JLab Connection)

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Online analysis How-To

PREX Main << Information for Shift Takers

Sign up for the Analysis shifts!

Analysis shift worker

The analysis shift worker is tasked with ensuring that the data is analyzed after it is taken, and with assisting in all tasks that the shift leader requests.

There are tools available for the analysis shift worker to check the quality of the data and analyze/reanalyze runs in Online analysis

Analysis Shift Worker Tasks

  1. Ensure shift crew is counting good coulombs properly and recording ABU's properly ((
  2. Assist shift crew in data taking as needed
    • help diagnose and solve CODA issues
    • answer questions about plots in Panguin
    • remind the TO to check the Panguin plots frequently
  3. Makes sure online analysis is up to date
  4. Look at beam quality
    • Look at runs from a previous good period and compare to the current runs
    • Watch for changes in means and widths over time
    • Log anything that you think is an issue that needs to be investigated and email the WAC
  5. Decide when to change IHWP settings
    • Each slug should have ~15 runs(at 50% efficiency), but the real measure is a total charge of at least 4.0 C (but not too much more than this, like 4.2C)
    • Keep track of the accumulated charge in the slug using the counter
      • If the current run had steady beam and no known issues, check the accumulated charge before it ends
      • If the accumulated charge is >4.0 C including all runs but the current run, and the current run is good, you can probably increment the slug
      • Ask the shift leader to follow the instructions at Flipper

Remote Shifts

Connecting to JLab

Monitoring the Shift

The Analysis shift worker should rely first on those standard webpages mentioned above, both to minimize taxing the Hall A computers' resources and to ease the adherence to a standard work-space among analysis shift workers.

That being said, analysis shift workers are encouraged to connect to the Analysis shift worker VCN session (described below) which should have useful screens and GUIs that persist between analysis shifts among the different workers (again, to make life easier)

Standard Screens and Where to Find Them

  • Strip Charts
    • From apar@adaq2
ssh -f hacuser@hacweb7 'myaplot .....'
  • Expert (alarm-lite) GUI
    • From apar@adaq2
  • JMenu or NewTools
    • From a-onl@aonl1
jmenu or NewTools

Modes of JLab Connection

VNC Sessions

We have 3 dedicated VNC sessions maintained by the collaboration for general use:

  • a-onl@aonl1 :1 - For the Shift Leader and Target Operator to share between themselves, containing useful GUIs and anything that they may want to both visualize without physical proximity
  • a-onl@aonl2 :1 - For the official analysis shift workers. This one should be maintained and contain standard useful screens for the analysis shift workers to share amongst themselves
  • a-onl@aonl3 :1 - For any experts on call who may need to access standard screens, without interfering with the dedicated shift workers. Use of this VNC session should be coordinated by the on call experts and the Run Coordinator

To access one of these VNC sessions execute:

vncviewer aonl# :1 --Shared=1



More dedicated VNC sessions can be created for use by experts off site to speed their data analysis and investigations. Please contact Cameron before adjusting any VNC sessions or settings, or to obtain the VNC password.