Info collection for the BAM

Version 1.1 by sendels on 2019/08/09 12:46


  • the relevant data is the Arrivaltime FLASH.SDIAG/BAM/4DBC3/LOW_CHARGE_ARRIVAL_TIME


  • There are now (since March 2017) LOW and HIGH charge channels. for now the LOW_CHARGE Channel is the relavant one.


  • bigger numbers indicate later arrivaltime of the electrons


  • the arrivaltime sould be within -20 ps and +20 ps . otherwise there might be a problem ...


  • There is a BAM status parameter: FLASH.SDIAG/BAM/4DBC3/BAM_STATUS.1 (the 1 indicates FLASH1)
    • bit 0 (value: 1) = data is valid,
    • bit 1 (value: 2) = at least 1 bunch is present,
    • bit 2 (value: 4) = calibration is on,
    • bit 3 (value: 8) = internal feedback is on,
    • bit 4 (value: 16) = tuning mode is on


  • if DBC3 is not working then also 3DBC2 can be used. there is a linear correlation between BC2 and BC3

(from Marie: der groesste Drift-Beitrag kommt immer aus dem Injektor (also alles zw. Injektorlaser und ACC39) Einfluss von ACC23 ist deutlich kleiner. Im Mittel hat man einen linearen Zusammenhang zw. Ankunftszeit BC2 zu BC3.)



more Info:



Streak camera info


  • the streak camera measures the delay between optical (amplified) laser and FEL (dipole radiation). - not in respect to the master clock !
  • streak camera ONLY delivers data which is averaged over seveal 10 seconds. there is NO shot to shot info.
  • a larger value of the streak camera delay indicates that the optical laser comes later than the FEL (or FEL earlier than the laser ...)