Last modified by sndueste on 2025/02/06 10:58
From version 4.1
edited by cpassow
on 2020/04/23 17:41
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To version 6.1
edited by cpassow
on 2020/04/24 10:42
Change comment: There is no comment for this version

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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 -\\
20 +=== more Info to the BAM: ===
21 21  
22 -=== more Info: ===
23 -
24 -\\
25 -
26 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 27  * [[talk by Marie (2011)>>attach:FLASH-seminar-2011_BAM_study_results.pdf]]
28 28  * contact: Marie Kristin Czwalinna
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29 29  
30 30  \\
31 31  
32 -== Streak camera info ==
28 += General information for the data analysis of pump-probe experiments =
33 33  
34 34  \\
35 35  
32 +please have a close look to the publication:
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 +\\
40 +
41 +Here is a summary of the ideas:
42 +
43 +== Streak camera info ==
44 +
36 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 ...)
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 ...)
39 39  
40 40  \\
41 41  
42 -== Calculate pump-probe delay ==
51 +\\
43 43  
53 +{{collapsible-panel EXPAND="Correction of pump-probe delay" COLLAPSE="Correction of pump-probe delay" Start="true" atlassian-macro-output-type="INLINE"}}
54 +{{info}}
44 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 -
56 +** usually the BAM signal has to be added to the delay ...
57 +** 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
48 48  * Streak camera: difference between electrons and optical laser
49 49  ** it is a slow signal and should only be used as a rolling average over multiple minutes
50 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 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 52  ** addition/subtraction is dependent on the setup and have to be checked
63 +{{/info}}
64 +{{/collapsible-panel}}