Last modified by sndueste on 2025/02/06 10:58
From version 2.1
edited by sndueste
on 2019/10/02 09:22
Change comment: There is no comment for this version
To version 4.1
edited by cpassow
on 2020/04/23 17:41
Change comment: There is no comment for this version

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1 -XWiki.sndueste
1 +XWiki.cpassow
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1 1  * the relevant data is the Arrivaltime FLASH.SDIAG/BAM/4DBC3/LOW_CHARGE_ARRIVAL_TIME
2 -* besides the arivaltime from FLASH1 there is also the FLASH2/3 electron arrival time saved. The BAM data is saved for the complete RF pulse. First bunches are from FLASH1 then there is a gap for switching and then there is a second part for FLASH2 (starting at the FLASH2 start time (recorded in DAQ))
2 +* besides the arivaltime from FLASH1 there is also the FLASH2/3 electron arrival time saved. The BAM data is saved for the complete RF pulse. First bunches are from FLASH1 then there is a gap for switching and then there is a second part for FLASH2 (starting at the FLASH2 start time (recorded in DAQ as {{code language="none"}}/FL2/Timing/start time flash2{{/code}}))
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36 36  * the streak camera measures the delay between optical (amplified) laser and FEL (dipole radiation). - not in respect to the master clock !
37 37  * streak camera ONLY delivers data which is averaged over several 10 seconds. there is NO shot to shot info.
38 38  * a larger value of the streak camera delay indicates that the optical laser comes later than the FEL (or FEL earlier than the laser ...)
39 +
40 +\\
41 +
42 +== Calculate pump-probe delay ==
43 +
44 +* BAM measurement: difference between electrons and timing system
45 +** the BAM signal has to be added, but it seems that the sign is the different for FLASH2
46 +** it is the best to test addition/subtraction and check the results on a step function (more/less sharp)
47 +
48 +* Streak camera: difference between electrons and optical laser
49 +** it is a slow signal and should only be used as a rolling average over multiple minutes
50 +** if you see a drift in the streak camera which you do not see in the BAM it is resulting from the optical laser
51 +** if this (BAM - streak camera signal) is significant e.g. 200 fs over 1 h, it means the drift compensation was probably off and it should be compensated
52 +** addition/subtraction is dependent on the setup and have to be checked