LArIAT Run 2 Shifter Instructions » History » Version 49

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Jason St. John, 04/03/2016 01:41 PM

LArIAT Run 2 Shifter Instructions

Remember to call MCR (x3721) at the beginning and ending of each shift!!!

Please don't hesitate to contact the experts when something doesn't look right!!!

Before your first shift at LArIAT check here so you're ready.

When starting the shift

  • Check the pressure in the wire chambers’ gas bottle and the slow bubbles in the wire chambers’ gas panel “Return” bubblers. If you don’t know how to do it or where it is, shame on us we haven’t showed you yet (see Wire Chamber Gas/Electronics Instructions).
    • If the pressure is less than 18 psi, please email the Run Co-ordinator at .

For a shift at Fermilab:

  • From an MCenter machine, such as ftbflx18 or ftbflx15:
    • Log in with username = ftbf_user.
  • From a ROC West machine, such as lariat-cr-02:
    • Log in with username = lariat.
  • Password is YOUR kerberos password, then it will ask for YOUR kerberos principal. (Reverse from usual order)

From a remote shift:

  • Start the Fermilab Virtual Private Network (available here
  • Open an ssh tunnel to the shift computer
    ssh -C -L 5900:localhost:5900 
  • Direct your VNC viewer to localhost:5900. Password is the same as the docdb password. We recommend RealVNC but others are worth trying in case they work better for you.

Refresh the kerberos ticket on the shift computer

  • Once logged in, open a terminal window. If "klist" doesn't show that you have a valid kerberos ticket, get one: kinit <your_kerberos_principal>
  • If ftbf_user (MCenter) or lariat (ROC West) is already logged in - reset the kerberos ticket: kdestroy and then kinit <your_kerberos_principal>
  • Be careful you're that you're on the correct terminal and not on a DAQ terminal when you issue kdestroy.

Final steps

  • ACNET/Synoptic does not always keep running properly after such reset, so it's recommended to restart both of them (see instructions in the next point)
  • Open in a new tab Using ACNET for monitoring This page contains the instructions to monitor the beam status through ACNET.
  • Also open Synoptic
  • Open Operations Elog in the new tab This is the Main Control Room (MCR) Elog. Use it to check any possible problem affecting the MCenter beam.
  • Log the previous shifter out of the LArIAT Elog (if they are logged in), and log yourself in. Make a new entry with the "Start of Shift Checklist" form.

During the shift

  • If you have questions, call an expert! LArIAT Call List
  • Or, you can use Google Hangouts: send an email to to get invitation.
  • As well as Google Hangouts, you can Skype an expert! How to access Skype:
  • On the ftbf_user or lariat account:
    • "cd ~/Downloads/skype-"
    • "skype"
  • You can find the password in the top right blue box of the whiteboard in the control room.

What beam should I request? The Run Plan lists current and upcoming beam requests, along with the other MCenter activities going on.

Starting a new run

  • Open in a new tab LArIAT DAQ Instructions and follow the instructions to start a new run.
  • The DAQ should make an e-log entry for your automatically. If the LArIAT e-Log webpage doesn't load, try one of the following links: db4 ,db5 or db6 , or you may already have an instance of the e-Log running.
  • Special cases:

During an ongoing run

  • Monitor the beam status using the instructions in the Using ACNET for monitoring, namely
    • the S60 page of ACNET and
    • the profile plots for MC7WC1 and MC7WC2.
    • From ~ftbf_user/acnet or ~lariat/acnet, run ./ to open the Synoptic displays.
  • Run Status Webpage to monitor the run status (run number, number of spills, number of triggers, etc)
  • Note that, on the Run Status Webpage, if the run time appears red, and the spills stop increasing, the run has come to a stop. It will also speak an audible alert, once.
    • In order to get it running again, you can issue the 'lariatReset' command in the DAQ terminal, followed by 'go'.
    • Sometimes the Run Status page freezes. If this happens, see if your DAQ command line has reset. If so, the run has ended. Follow above instructions.
  • Did the run number fail to increment? If the number has reset to a low number such as 1 stop ther run and then edit /opt/lariat-online/config/runNumber.dat to correct the run number. Start new run after.
  • Online DQM to check basic data integrity.
    • If the rate of MWPCs data blocks duringe the beam spill is not very close to the data block rates of the other systems, debugging this is urgent.
      • On the Data Blocks page, monitor the "Data Block Time Stamps" graph. During the beam (1-5 s) the MWPC line should follow a similar line shape to the V1740 and V1751 lines, and not be too far below.
      • You can isolate plots by hovering over the legend. To confirm that data isn't being sent, go to the 'Log' tab, and see if a orange error message appears: "No data stream from [component]!"
    • At end of each run download the tarball at the bottom of the "Home" page. Add all of the DQM plots to a new elog entry.
  • Use the event viewer to see TPC events. See Event Viewer Instructions . If you decide to post some interesting event in the e-log, please write the number of the spill/event in the title or content of the entry. It's much easier to search for them later!
  • Useful: Recent run history , python scripts for making DQM plots


Important! Follow instructions in link below if cathode HV trips off due to LAr level interlock.
Drift HV TPC Cathode Voltage

If the Troubleshooting Page doesn't help, call an expert

*If a VME Power Supply has to be turned off in an emergency situation (e.g. problem with TPC PMTs) - turn off the regulate function first, then put the decreasing voltage values in the quick ramp window, go to 0 and then turn off! *

When the run has ended

  • From the e-log entry which started this run, make a related entry summarizing the run. Add the final DQM plots (tab "Home" in the Online DQM).
  • On the Online DQM , go to the Data Blocks tab and report the number of V1751 triggers, and the same for the V1740's, both for board 0 only.

At the end of the shift

  • Make an entry in the e-Log using the form "Shift Summary" summing up the relevant information from the shift (make sure to include the total trigger counts for the V1751s and V1740s). For any other information to be posted in the e-Log during the shift use the "default" form.
    1. Call MCR to stop the beam
    2. Also ask the MCR to release a key so you can put the enclosure into open access. (The open access rule is valid only till we'll be ready for the cryostat filling).

Remember to call MCR at the beginning and ending of each shift!!!

Remember to call MCR at the beginning and ending of each shift!!!