Last modified by sndueste on 2025/02/06 10:58
From version 5.1
edited by sndueste
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To version 9.1
edited by sndueste
on 2022/09/07 11:46
Change comment: There is no comment for this version

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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}}))
1 +=== Some basic stuff: ===
3 3  
4 -\\
3 +* The relevant data is the arrival time FLASH.SDIAG/BAM/4DBC3/LOW_CHARGE_ARRIVAL_TIME
4 +* Besides the arrival time 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}}))
5 +* There are LOW and HIGH charge channels. For now the LOW_CHARGE Channel is the relevant one.
6 +* Bigger numbers indicate later arrival time of the electrons
7 +* The arrival time should be within -20 ps and +20 ps - otherwise there might be a problem ...
5 5  
6 -* There are now (since March 2017) LOW and HIGH charge channels. for now the LOW_CHARGE Channel is the relavant one.
7 -* bigger numbers indicate later arrivaltime of the electrons
8 -* the arrivaltime sould be within -20 ps and +20 ps . otherwise there might be a problem ...
9 -* There is a BAM status parameter: FLASH.SDIAG/BAM/4DBC3/BAM_STATUS.1 (the 1 indicates FLASH1)
10 -** bit 0 (value: 1) = data is valid,
11 -** bit 1 (value: 2) = at least 1 bunch is present,
12 -** bit 2 (value: 4) = calibration is on,
13 -** bit 3 (value: 8) = internal feedback is on,
14 -** bit 4 (value: 16) = tuning mode is on
9 +=== Data structure ===
15 15  
16 -\\
11 +(% style="color: rgb(0,0,0);" %)The details about the functionality and the data structure can be found on the page: (%%)**[[ BAM Data Structure>>url:https://confluence.desy.de/display/SDiagPublic/BAM+Data+Structure||shape="rect"]]**
17 17  
18 -* if DBC3 is not working then also 3DBC2 can be used. there is a linear correlation between BC2 and BC3
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 28  = General information for the data analysis of pump-probe experiments =
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48 48  
49 49  \\
50 50  
51 -== Calculate pump-probe delay ==
38 +\\
52 52  
40 +{{info title="Correction of pump-probe delay"}}
53 53  * BAM measurement: difference between electrons and timing system
54 54  ** usually the BAM signal has to be added to the delay ...
55 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 57  * Streak camera: difference between electrons and optical laser
58 58  ** it is a slow signal and should only be used as a rolling average over multiple minutes
59 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 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 61  ** addition/subtraction is dependent on the setup and have to be checked
49 +{{/info}}