Laser - Experts Only

The experts of the UV laser system will have the whole paper documentation in the LHEP Bern office. Proper Guidelines require the full understanding of the Standard Operation Procedures - SOP developed together with Fermilab's ESH&Q department. The expert on-site is responsible for the keys and will take measure to ensure no unauthorized run of the UV laser is possible.

Laser runs

configID 793 (July 2019)

configID 463 - hmm
ConfigID 312 (compressed, low rate < 2Hz and single shots)
ConfigID 303 (compressed, rate >2 Hz)
ConfigID 285 (not compressed data)
configID 638 (as of 20.Sept 2017)

Access to laser servers

Have your kerberos principal added to the k5login on the laser servers.
Contact Matthias or Michele for this.

access the machines with ssh to laser@uboonelaserone (upstream) or laser@uboonelasertwo (downstream)

Initialize Laser

execute cdlaser

Laser Python mode

bpython i mac/
turns laser flashlamp ON
- gives the laser interactive mode (laser.XXX are the commands)

. For single shots: .setRate(0) and .openShutter() .singleShot()

Attenuator (laser pulse energy)

bpython -i mac/


Aperture / Iris


M2 and M3

UPSTREAM nominal positions:
M2, 111: 1866
M2, 112: -19460

M3, 121 ("Rohr"): 2816 (10/1/2015, ML)
M3, 122 ("Stebe"): -9160 (10/1/2015, ML)

DOWNSTREAM nominal positions:
M2, 211: 4374
M2, 212: 1833

M3, 221 ("Rohr"): -4750 (optimized 8/18 ML, YC)
M3, 222 ("Stebe"): 5500 (optimized 8/18 ML, YC)

Cold mirror

Boundaries UPSTREAM
- 107.496 rotary toward wire
- gaps at around 82, 87.5, 93.5, 100, 106
- 81.468 rotary toward cathode (at end switch)
- 012607765 linear up
- 008701735 linear down

- 159.12 rotary toward wire
- gaps at around 173.5, 180.5, 184.5, 189.5, 194.5, 197.5 (unsure)
- 202 rotary toward cathode (possible gap here)
- 012460047 linear up
- 008803758 linear down

General Guidelines to follow

  • Check that no person is on the platform or lower levels at LArTF.
  • Check the mechanical integrity of the laser boxes at LArTF.
  • At the beginning of the DAQ run period, place and turn the key to allow remote access to the UV laser power supplies.
  • Check the light tightness by crosschecking the PMT event rate.
  • Set the DAQ system to UV Laser mode.
  • Check that the PMT HV is turned off.
  • Turn on the UV laser remotely, and wait for the warming up of the device (about 25 minutes).
  • Start the UV laser run.
  • Stop the UV laser run.
  • Turn off the UV laser.
  • Leave the UV laser mode.
  • At the end of the DAQ run period, remove the key to the UV laser power supplies at LArTF.

More Details