1 / 12

EO

EO. Change this summary to WHAT ACTUALLY HAPPENED RATHER THAN PARAPHRASING FROM shift summaries. 2010 data (Period 9-10) June 27 set-up shift July 2 set-up shift July 6-7 THz set-up July 18 FEL set-up 2011 data Feb 20 set-up shift Mar 14 “no result”

kioko
Download Presentation

EO

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EO • Change this summary to WHAT ACTUALLY HAPPENED RATHER THAN PARAPHRASING FROM shift summaries. • 2010 data (Period 9-10) • June 27 set-up shift • July 2 set-up shift • July 6-7 THz set-up • July 18 FEL set-up • 2011 data • Feb 20 set-up shift • Mar 14 “no result” • Mar 16 “First EO characterisation of lasing electron beam” • Mar 21 #2361-2. HIGH RESOLUTION VERSION. “Observed EO signal and studied it as a function of beam steering, buncher charge, LC phase.”  • Mar 23 #2368 “Short time spent on EO signal studies. Good news is that it worked almost immediately with very little set-up required.”  • 19 April 2011 #2420-2421. Some brief scanning of AR1-Q1 and AR1-SEXT-1

  2. 2 July 2010, Shift #1901 • Preliminary set-up with THz set-up • Buncher power = 550 W, BC1 = -20 BC2 = +20 LC = +18 • From Log #1901. “Signal weak - only a strong signal every 5-15 shots on the scope”

  3. 6-7 July 2010 • THz set-up Buncher power = 530 W, BC1 = -20 BC2 = +20 LC = +18 (i.e. restored #1901)

  4. 6 July 2010 #1915 • \\Spj36dell\c\EOexpt\scans_6jul10 • Restored “THz” set-up from #1901 and tried to optimise EO signal using linac phase scan • “From the EO signal Steve estimates there is a ~3ps timing jitter on the beam.” • “We have done some scans changing the phase (not changing the gradient) the best EO signal is at about +17 degrees.” • 20 files containing ~ 17000 shots of the scope trace, not labelled or recorded with info as to what linac phases were. • 17000 at 10 Hz (rep rate of TW laser) == ½ hour of data ?? • Scanning the linac phase affects TOA, so to measure jitter have to know that the linac phase is not being scanned during the data.

  5. 6 July 2010 #1915 First 6 summary files all the shots look like this successive shot examples see signal appearing on left and moving to right, is this the timing scan ?

  6. 7 July 2010 #1916 • Restored BURT 1100706_223443 and restored RF settings (+18 deg from crest) from yesterday's shift (22:23) • Yesterdays shift = 6 July = THz set-up • “Returned to +18 deg linac phases for EO work. Decent energy recovery.” • “Moving laser timing to observe electron bunches at different parts of the train” Summary16.mat

  7. 21 March 2011 #2361-2 • Shift summary. “Observed EO signal and studied it as a function of beam steering, buncher charge, LC phase.” • This is a misleading summary. It means ST2-DIP-04 was steered to improve signal, buncher POWER was changed to improve signal, and LC phase was scanned at end of shift • Also AR1-sextupole-01 was varied but this isn’t mentioned in the summary. • This was the ‘Temporal Decoding’ technique (was it ‘Spectral Decoding’ in 2010) for high resolution • "FEL-03" i.e. #2349 12:19 set-up but without lasing attempted. • At end of shift quick measurents of EO signal vs • AR1 sextupoles • Linac phase • The quick measurements at end of shift low resolution version was switched to see shift note at 15:16.

  8. 21 March 2011 #2361-2 • Quality of some of the Gaussian Fits.

  9. 21 March 2011 #2361-2 • AR1-SEXT-01 (probably) at 0 and 3 A. • Tried Gaussian fits to the EO signals. mean position of EO signal sigma of EO signal blue AR1-SEXT-01 = 0 A, red AR1-SEXT-01 = 3 A

  10. 23 March #2368 • “Looked at EO signal vs AR1-SEXT-01. Seems to be most compressed bunch at sext = 4.5 A with the current BURT” • “Then changed the AR1 quads by small tweaks (0.01 A) and then found a setting where the EO signal looked better with SEXT = 0” • So not really parameter scans. • Calibration hinted at in \EOexpt\23Mar2011\AliveEOTDfig.m and AliceEOTDfig.m (plots at aliceeotdfigb.eps) • “CalibrationConst = 1/50; %estimate only - for IRUVX figure !%7.6993*1e-3;” • This looks a bit different to the only previously published EO plots EOexpt\scans_7july2010\wednesdaySummary27.mat ( was originally sent these plots from Trina by email, which indicated the filename)

  11. 19 April 2011 #2420-2421 • 1 shift setting up • Next shift attempting param scans AR1-Q1 and AR1-SX-1 done right at the end in ..Summary29-31.mat files.

  12. Questions • What does the shot from the MATLAB files mean? Single electron bunch? Or average over several bunches within train? • What do two subsequent bunches mean? Bunches from different trains? • Transverse distance from bunch to crystal. • “Background” peaks compared to main peak. • How is calibration calculated, what does 1 bin on the 1280 bin histrogram mean, i.e. can you really resolve bunch features on a 1/1280 resolution? • Was ‘spectral decoding’ or ‘temporal decoding’ EO techniques used ?

More Related