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Datataking Procedures

First Drs Calibration

Notice: dimscript for this procedure: ScriptsForDimCtrl!/FirstDrsCalibration!.dim

Remote-datataking: In case of remote data-taking this section can be skiped. In this case you can directly open the lid, and start with the data-taking including the DRS calibration.

0. Do _Start_ (DRS Calibration) in the fad-tab
1. Take *DRS: Pedestal* (1000 events)
2. Take *DRS: Gain* (1000 events)
3. Take *Pedestal* (1000 events)
4. Switch to FITS file format in the fad-tab
5. Take *Pedestal* (1000 events)
6. Switch on the temperature control (Feedback-tab: *Start*, *Enable output*)
7. Switch on the BIAS voltage (Set the global offset to one DAC count in the Bias tab and wait until the temperature feedback has ramped the voltages properly)
8. Take *Pedestal* (1000 events)
9. Switch off the bias voltage (*Set all to 0*)
10. Open the lid

Normal Datataking

0. Move the telescope to wobble position 1
1. Make sure Bias voltage is off
2. Do _START_ (DRS Calibration) in the fad-tab
3. Take *DRS: Pedestal* (1000 events, MCP *Start Run* on GUIs left side)
4. Take *DRS: Gain* (1000 events)
5. Take *DRS: Pedestal* (1000 events)
6. Switch to FITS file format in the fad-tab
7. Take *DRS: Pedestal* (1000 events)
8. Take *DRS: Time* (1000 events)
9. Do _RESET_ (DRS Calibration) to reset the secondary baseline in the fad-tab
10. Take *Pedestal* (1000 events)
11. Switch to FITS file format in the fad-tab
12. Send somebody out at the backdoor to measure the the sky-brightness with the sky-meter at the rough direction the telescope is pointing and write it down in the logbook
13. Take *Pedestal* (1000 events)
14. Switch Bias on (set to one DAC count and wait for the feedback)
15. Take *Pedestal* (1000 events)
16. Take *External light pulser* (1000 events)
17. Take data with full trigger area (four times 5 minutes)
18. Move the telescope to wobble position 2
19. Send somebody out at the backdoor to measure the the sky-brightness with the sky-meter at the rough direction the telescope is pointing and write it down in the logbook
20. Take *Pedestal* (1000 events)
21. Take *External light pulser* (1000 events)
22. Take data with full trigger area (four times 5 minutes)
23. Go on with the beginning of the data taking procedure

ratescan

0. Track a dark region
   • low zenith (<30°)
   • no bright star
   • no direct moonlight in the camera
   • examples
     • around 0:00 UTC: ra = 13.46667, dec = 27.12833
     • around 4:00 UTC: ra = 21.45, dec = 14.9
1. Take a run with type ratescan with unlimited event and unlimited duration (for configuring all programms)
2. Ratescan/START_THRESHOLD_SCAN x y c

variables:

• x: start threshold
• y: end threshold
• c: stepsize (if negativ ratescan starts with |c| and handle it dynamically, if the ratescan needs too much time)

Configuring manually:

• Stop ratecontrol (I'm not sure if this is necessary)
• ftmctrl/SET_DEAD_TIME 0 (in fact thats the minimum equal to 8ns (you can also set this value in the GUI)
• GUI: no interleaved pedestal, no interleaved extLP, only physic triggers

Ampl. vs Bias measurement

1. Track a dark region (same requirements as for the ratescan, see above)
2. Do a DRS calibration
3. Feedback/Start_Current_Control -1.0 (maybe Enable_Output yes)
4. wait for 2 - 3 feedback voltage corrections
5. switch to fits format
6. Now take an external lp run with 1000 events
   • be aware that for x = -1.0, -0.9, its possible to trigger 0 events. Than you can go on with the next overvoltage
7. Increase voltage offset by 0.1 V go on with the next light-pulser run
8. do this until +0.5 V offset

Write down following in the logbook:

• Offset
• median Voltage
• median Current
• runnumber

Dim Scripts

In FACT++/ScriptsForDimCtrl you will find the following scripts that could do parts of aboves procedures automatically.

script_name | function :- | :-

FirstDrsCalib.dim | taking a first DRS calibration as described above DataTaking1.dim | procedure from step 2 to step 18 DataTaking2.dim | procedure from step 21 to step 23 (which btw. is the same as step 16 to step 18) ResumeDataTaking.dim | can be used if DataTaking crashes during the first of a 4x5min run set to take 4 runs of 5 mins in a row Take<source_name>.dim | procedure from step 1 to 23 with for Source <source_name> (2 Wobble positions) AmplVsOv.dim | do steps 2 to 5 of the Amplitude vs Bias measurement with an overvoltage of x

Scripts can be started in the dimctrl screen on data by typing: .x ScriptsForDimCtrl/<script_name>

Scripts can be stopped via dimctrl --stop in a bash

• this command starts a client of the dimctrl-server (which runs the script) and sends a STOP command to the server
• its only possible when the first dimctrl was started as a server (dimctrl --server)

if you want to only take the second wobble position the script can be started by: .x ScriptsForDimCtrl/Take<source_name>:2

scripts available for the following sources: source | <script_name> :- | :-

Crab | TakeCrab.dim Mrk421 | TakeMrk421.dim Mrk501 | TakeMrk501.dim 1ES1218+304 | Take1218.dim