Laser Calibration of EC

There are programs and scripts that control the calibration process. These are chosen based on the LAS_EC configuration and are started as the DAQ goes through the various transitions.


Basic Steps:

(Note: The status of the beam is irrelevant during EC laser calibrations as far as the data recording is concerned.)

  1. DAQ up and running: Make sure the DAQ is running and is at the configure transition. (From a production run you need to reset to be able to configure.)
  2. Configure: Choose the configuration LAS_EC.
  3. Normal run procedure: Download, Prestart, Go
  4. Done: Wait for the DONE message to appear and then end the run. (A gui with two text screens will appear after you are running. The calibration status and progress will be printed to these areas. The messages are for calibration experts and do not need to be read. When the calibration finishes a DONE message will appear in a new window. You merely end the run in the normal way. The message windows should be left open during the run but can be closed after the end using the standard window close menu in the upper left-hand corner of the window.)
  5. Resume Production: You should return to the production configuration and proceed with the run plan.


What should happen

As soon as the download is finished the laser and filter are set to their initial configurations. The laser requires a 5-minute warm-up so triggers may not be present immediately. Within 5 minutes the trigger rate should rise to a few hundred events/s and then recede to a few hertz with one final surge to a few hundred Hz at the end. The total run time is about 15 minutes. Initially the trigger is from radioactive sources (300 Hz). This is followed by 6 intensity settings for the laser (10 Hz). At the end a few more source events are recorded (300 Hz). The total number of events should reach about 16k.

Since calibration events are triggered by other than beam related events, the beam can be either on or off during an EC calibration run. (No actual production triggers will be accepted during calibration.)


Should you encounter a problem of any type, please note the problem and send an email to You should be able to continue normal production running in any case.



If you did end in an error you can check the following:

  1. Execute command
  2. EC_laser_off

    on any clonxx window to turn off the EC laser. If the laser is already off the command does nothing. You can view the status using the command



  3. Kill the unix_master if it is running on clon03.

ps -ef | grep unix_master

kill xxxx

where xxx is the pid of the unix_master if found.