Last modified by sndueste on 2025/02/06 10:58
From version 5.1
edited by sndueste
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To version 2.1
edited by sndueste
on 2019/10/02 09:22
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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 as {{code language="none"}}/FL2/Timing/start time flash2{{/code}}))
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))
3 3  
4 4  \\
5 5  
... ... @@ -17,45 +17,22 @@
17 17  
18 18  * if DBC3 is not working then also 3DBC2 can be used. there is a linear correlation between BC2 and BC3
19 19  
20 -=== more Info to the BAM: ===
21 -
22 -* [[LINK to detailed infos from MSK (may only work inside DESY network)(% class="confluence-embedded-file-wrapper confluence-embedded-manual-size" %)~[~[image:url:http://hasfweb.desy.de/pub/TWiki/TWikiDocGraphics/external-link.gif~|~|width="13" height="12"~]~]>>url:http://www.desy.de/~~mbock/pages/BAM_daq_channel_descriptions.html||rel="nofollow" shape="rect" class="external-link"]]
23 -* [[talk by Marie (2011)>>attach:FLASH-seminar-2011_BAM_study_results.pdf]]
24 -* contact: Marie Kristin Czwalinna
25 -
26 26  \\
27 27  
28 -= General information for the data analysis of pump-probe experiments =
22 +=== more Info: ===
29 29  
30 30  \\
31 31  
32 -please have a close look to the publication:
26 +* [[LINK to detailed infos from MSK (may only work inside DESY network)(% class="confluence-embedded-file-wrapper confluence-embedded-manual-size" %)~[~[image:url:http://hasfweb.desy.de/pub/TWiki/TWikiDocGraphics/external-link.gif~|~|width="13" height="12"~]~]>>url:http://www.desy.de/~~mbock/pages/BAM_daq_channel_descriptions.html||rel="nofollow" shape="rect" class="external-link"]]
27 +* [[talk by Marie (2011)>>attach:FLASH-seminar-2011_BAM_study_results.pdf]]
28 +* contact: Marie Kristin Czwalinna
33 33  
34 -Evgeny Savelyev, et al,  //Jitter-Correction for IR/UV-XUV Pump-Probe Experiments at the FLASH Free-Electron Laser//,
35 -New J. Phys. **19**, 043009 (2017), [[https:~~/~~/doi.org/10.1088/1367-2630/aa652d>>url:https://doi.org/10.1088/1367-2630/aa652d||shape="rect"]]
36 -
37 -describing in detail the usage of BAM, streak camera and delay line data in order to get the actual time axis as reliable as possible.
38 -
39 39  \\
40 40  
41 -Here is a summary of the ideas:
42 -
43 43  == Streak camera info ==
44 44  
45 -* the streak camera measures the delay between optical (amplified) laser and FEL (dipole radiation). - not in respect to the master clock !
46 -* streak camera ONLY delivers data which is averaged over several 10 seconds. There is NO shot to shot info.
47 -* a larger value of the streak camera delay (typically) indicates that the optical laser comes later than the FEL (or FEL earlier than the laser ...)
48 -
49 49  \\
50 50  
51 -== Calculate pump-probe delay ==
52 -
53 -* BAM measurement: difference between electrons and timing system
54 -** usually the BAM signal has to be added to the delay ...
55 -** it is the best to test addition/subtraction and check the results on a step function (more/less sharp) - if there is no change of the data with + and - there is anyway something wrong. please contact your local contact for more information / help
56 -
57 -* Streak camera: difference between electrons and optical laser
58 -** it is a slow signal and should only be used as a rolling average over multiple minutes
59 -** if you see a drift in the streak camera which you do not see in the BAM it is resulting from the optical laser
60 -** 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
61 -** addition/subtraction is dependent on the setup and have to be checked
36 +* the streak camera measures the delay between optical (amplified) laser and FEL (dipole radiation). - not in respect to the master clock !
37 +* streak camera ONLY delivers data which is averaged over several 10 seconds. there is NO shot to shot info.
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 ...)