Beam Line For Schools Detector Shifter Instructions

This page is designed to help Detector Shifter of the BL4S experiment. Please be sure that you read the general shift instructions in page BL4SShiftIntroduction.

The duties of the Detector Shifter can be summarized as:

General Duties and Checklist


While the Run Control Shifter and the Shift Leader are driving the car, you are responsible for all the technical issues about the detectors. It is like the pit stop at the Formula race. There are different kinds of detectors operating under different conditions. You are the one who should check them and act when there is a problem. You should always be in contact with the Shift Leader and the Run Control Shifter. If you would like to change any configuration or if there is a problem, you should warn them to stop the ongoing run. BL4S Detector Shifter is responsible to observe and change the HVs and LVs, taking pedestal runs and monitoring the detectors through the DAQ. It is advised to check the whole system at least once in an hour. Here is a checklist which can help you.

  • Check the HVs. Is there any problem? Any big change? Any Trap?
  • If possible, check the LVs. Is it blinking?
  • Did you take pedestal data before the long run?
  • Run the Monitoring Program.
  • Check the histograms in Monitoring Program shown in BL4SWhiteBoard. Are they similar to the ones described in BL4SWhiteBoard?
  • Check the BL4S E-Log if there is any update from other desk.
  • If there is any problem you have, make an e-log about it.
  • Have Fun!

Checking HV's

HV stands for High Voltage. All the detectors, used in the experiment, need high voltage to operate. Detector shifter is responsible to observe the HV's during the shift. You can open the HV menu by clicking BL4S _HV icon on the desktop. In this interface you can not use your mouse. You should use the keyboard to operate.


After you click on the icon you will see a screen like:


Press any key to login to the system. Then you will see a screen like:


Enter the following for username and password ->


password: user

Yes, this password is not safe at all. Never use such obvious passwords yourself. You may ask: Why did we not pick a better password?
Well, physicists tend to be lazy (not an excuse).

You can now access the HV module. Which looks like:


Here you can navigate through the menu by using the arrows on the keyboard. Press enter on "Main", then select "Channels" by pressing "Enter", you can now change the HV configuration and observe the values from the screen.


If you would like to turn on a HV channel navigate to the "off" on that line, then press "Space" in your keyboard. You will see the voltage rising. It is important to observe the voltages and currents while turning on/off. If you would like to turn off the channel, do the same again.

One can directly select V0Set (High Voltage level) and I0Set (Maximum allowed current) from here and change it. You can also change the names if there is a change in connections of the modules. However, during your shift, you should only turn on/off the modules. Do not change HV values and names unless the Shift Leader asks you to do so. Before starting data taking, one should turn on the relevant HVs. If there is any sharp change in monitored currents/voltages or if you are not able to increase HV of a module, discuss it with the Shift Leader and make an e-log about it.

Remember to turn off HVs before taking pedestal data.

While data taking, it is advised to monitor voltages and currents from time to time (at least every 15 minutes). The observed values should be in range of +/- 5V of the V0Set value. And the Currents should be stable.

If you would like to come back to the top menu, press on "tab" on the keyboard. You can exit from the screen by selecting "Log Out" in Main menu. This will only log you out, the voltages will stay as they were set. However, it is advised to keep the HV menu open in one of your screens.

IMPORTANT: Do not forget to turn off HVs before leaving the Control room if there will be no run afterwards.

Checking LV's

LV stands for Low Voltage. Delay Wire Chambers need LV to operate. LV Supplies will be in the experimental area and will be turned on at the beginning of the experiment. There is no remote connection for the modules, but you can check them from the stairs of the experimental area. If there is a problem, they will start to blink. If you see them blinking, discuss it with the Shift Leader and make an e-log about it. Check the low voltages twice during your shift and when you have access to the experimental area.

Taking Pedestal Data Before Long Runs

Pedastal literally means: "The base or support on which a statue, obelisk, or column is mounted." In the experiment, we are using QDC (Charge to digital converter) to measure lead glass calorimeter energies. Even when there is no real current going into the QDC (i.e. no detector signal), due to internal electronics, the deviations, some charge is collected. This charge is called pedestal charge and should be substracted from the signal data.

Before Long Runs or before the first run of the day, you should take pedastal data. Before taking pedestal data, tell the run controller not to start any run for a while. To take pedestal data perform the following steps:

  1. Find the second channel of the NIM coincidence unit.
    • Turn off channel A and D if they are on. (Detector Trigger and VME CORBO Module)
    • Turn on channel C. (Fake Trigger)
  2. Turn off HV of all Lead Glass Calorimeters. See Section "Checking HVs above"
  3. Run the pedestal program by clicking the "Pedestal" icon on the Desktop shown above.
    • 468950479.jpg
    • The program will show you the progress(as in the image below), and should finish in a seconds. If it is too slow or does not increase, check the coincidence unit and the signal generator.
    • If the standard deviations are too high (more than 10), recheck if the HV's are off.
    • If the mean or standard deviation (sigma) values are still high, do not use that channel for taking data. Change the connections and the config file according to it.
    • !!! Do NOT forget to write down the pedestal file name !!!
  4. You can exit by pressing ENTER button.
  5. Turn the HV of Lead Glass Calorimeters back on.
  6. Change the trigger back to detector coincidence but turning off channel C, turning on channel A and D in the coincidence unit.

After you finished taking pedestal data, do not forget to copy the name (marked as red in the screen) of the file and write an e-log about it including run number of the first run with this pedestal data.

After you are done, tell the run control shifter that you are done with the pedestal run and you changed the logic back to the data taking configuration and s/he can start a new run.

Checking Online Histograms

During the runs, the run control shifter is responsible for starting and stopping the runs. But you can still monitor DAQ system from your computer. To monitor the DAQ system, click on the BL4S _DAQ icon on your desktop.


A screen like below will pop up:


Here you can monitor the runs. You can find Run Information, Run Control State and the Errors. For more information visit BL4SRunControlShifterInstructions page.

If the system is in running state and if the counters are increasing in "Run Information & Settings" part, you can fill the Online Histograms (OH). To start filling online histograms click on the icon OH_START:


After the job is finished, the program will automatically exit. Now your histograms are ready.

By clicking on OH button on the DAQ screen at the top-right, you can access the histograms. The following screen will pop up:


Here find "part_BL4S" then "BL4S histograms". The histograms will be open on the right page and if you double click on any of the histograms you can see and play with them. Please check BL4SWhiteBoard see which histograms to check and their meanings!

-- SaimeSarikaya - 12 Aug 2014 -- CenkYildiz - 25 Aug 2014

Topic attachments
I Attachment History Action Size Date Who Comment
JPEGjpg 468950479.jpg r1 manage 18.5 K 2014-08-12 - 21:56 SaimeSarikaya Pedestal icon
PNGpng BL4S_DAQ.png r1 manage 61.7 K 2014-08-13 - 16:17 SaimeSarikaya  
PNGpng cfg.png r1 manage 161.6 K 2014-08-13 - 13:23 SaimeSarikaya configuration
PNGpng cfg_file.png r1 manage 110.3 K 2014-08-13 - 13:22 SaimeSarikaya config file
PNGpng geo_file.png r1 manage 99.5 K 2014-08-13 - 13:23 SaimeSarikaya geometry file
PNGpng hv2.png r1 manage 16.1 K 2014-08-12 - 18:25 SaimeSarikaya HV login screen
PNGpng hv3.png r1 manage 21.1 K 2014-08-12 - 18:25 SaimeSarikaya HV Menu
PNGpng hv4.png r1 manage 69.3 K 2014-08-12 - 18:26 SaimeSarikaya HV channels
PNGpng hv_screenshot.png r1 manage 24.9 K 2014-08-12 - 18:19 SaimeSarikaya HV screenshot
PNGpng ibus-engine.png r1 manage 4.3 K 2014-08-13 - 13:32 SaimeSarikaya config file icon
JPEGjpeg images.jpeg r1 manage 10.7 K 2014-08-12 - 21:48 SaimeSarikaya HV Icon
PNGpng invest-applet.png r1 manage 2.1 K 2014-08-13 - 16:35 SaimeSarikaya OH icon
PNGpng oh_display.png r1 manage 60.9 K 2014-08-13 - 16:35 SaimeSarikaya oh display
PNGpng pedestal_run.png r2 r1 manage 45.9 K 2014-08-13 - 14:55 SaimeSarikaya Pedestal run
JPEGjpg pit_stop.jpg r1 manage 59.1 K 2014-08-27 - 13:55 SaimeSarikaya  
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Topic revision: r14 - 2014-09-01 - SaimeSarikaya
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