Difference: Atf2LwLogBook20130207Shift (1 vs. 12)

Revision 1214 Feb 2013 - LaurieNevay

Line: 1 to 1
 
META TOPICPARENT name="Atf2LwLogBook"
Line: 353 to 353
  All of this is because there is some dispersion at our location. Changes in the energy affect the size and the position of the beam. Therefore, even without touching the linac during a scan, it will still drift and we'll be sensitive to it. Dispersion must be at least measured and ideally corrected. Furthermore, the beam based alignment wasn't performed so there was a clear drift in position with change in magnet strength.
Changed:
<
<
It is also possible that the beam is coupled coming into the LWIP area. In this case, the quad scan would rotate the beam as well. If the rotation angle is on the order of about 20mrad, the projected beam size by the laser-wire will be almost double its original value - dependent on proportions of electron beam of course and the unknown angle between the laser-wire axis and the nominal electron beam axis
>
>
It is also possible that the beam is coupled coming into the LWIP area. In this case, the quad scan would rotate the beam as well. If the rotation angle is on the order of about 20mrad, the projected beam size by the laser-wire will be almost double its original value - dependent on proportions of electron beam of course and the unknown angle between the laser-wire axis and the nominal electron beam axis.

Analysis files were put in 20130213_1436_qwd in ana directory manually.

 

Improvements to be made

  • Software to automatically analyse the quad scan from a list of files for each scan type

Revision 1114 Feb 2013 - LaurieNevay

Line: 1 to 1
 
META TOPICPARENT name="Atf2LwLogBook"
Line: 144 to 144
 
20130208_0158_lws_xy_errbar_plot.png 20130208_0149_lws_xy_errbar_plot.png
Deleted:
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<
Phase Scan
 
  • Initial scan - collisions!
  • Within 20um of aligned position.
  • Signal:Background ~ 1:8 so not great, but visible
  • Laser energy downstairs is estimated to be 33mJ post-ip although this is a slight underestimate
  • Comparing to previous shift, signal to background is approximately the same accounting for lower laser energy
Changed:
<
<
20130208_0224_lws_xy_fit_plot.png
>
>
Phase Scan

20130208_0224_lws_xy_fit_plot.png

Initial Collision Scan

20130208_0240_lws_xy_fit_plot.png

 

Laser-wire Vertical Scan
Changed:
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<
20130208_0253_lws_xy_fit_plot.png
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>
20130208_0253_lws_xy_fit_plot.png
 

Laser-wire Horizontal Scan
Changed:
<
<
20130208_0243_lws_xy_fit_plot.png
>
>
20130208_0243_lws_xy_fit_plot.png
 

Laser-wire Phase Scan
Changed:
<
<
20130208_0303_lws_xy_fit_plot.png
>
>
20130208_0303_lws_xy_fit_plot.png
 

Phase scan suggested a voltage of 4.47V and we set to that. Then repeated vertical scan, but signal vastly reduced. Setting back to original 5.0V and rescanning vertical.

Line: 181 to 187
 
  • Signal was dropping off despite returning to same position - not clear what's happening
  • Laser energy the same both before and after LWIP (photodiode & laseren)
Added:
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Things got worse...

20130208_0309_lws_xy_fit_plot.png

 
  • Phase, Horizontal, Vertical again...

  • Phase set to 4.74V, Horizontal set to 62. Vertical scan nonlinear about chaver:151, 60 points, 20 samples
  • Vertical scan quite good!!! Shows 1.7 +- 0.23um. Larger size before must have been due to horizontal offset.
  • Amplitude 0.72 vs background 4.2
Added:
>
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Re-aligned Proper Vertical Scan Apparently small...
20130208_0418_lws_xy_fit_plot4.png 20130208_0437_lws_xy_fit_plot3.png

More Sensible... Pretty Good
20130208_0453_lws_xy_fit_plot2.png 20130208_0504_lws_xy_fit_plot3.png
 

Horizontal Slicing

  • Centre is chahor:62
Line: 206 to 230
 
62 20130208_0418_lws 1.71 +- 0.26um
62 20130208_0517_lws 2.35 +- 0.16um
62 20130208_0527_lws 2.63 +- 0.18um
Changed:
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<
72 20130208_0536_lws 1.50 +- 0.2um  
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72 20130208_0536_lws 1.50 +- 0.2um
 

*set file: set13feb080608.dat

Line: 239 to 263
 
QM14FF Vertical Fit Horizontal Fit NonLinear Using s_ex = 235.0 Nonlinear using s_ex = horizontal
80 5.21 +- 0.84 202.2 +- 9.1 6.1 +- 0.3 6.27 +- 0.33
84 2.29 +- 0.6 138.1 +- 9,3 5.0 +_ 0.3 6.25 +- 0.32
Changed:
<
<
86 20130208_0701_lws - problem with this file 162.0 +- 6.3 4.26 +- 0.3 5.21 +- 0.34
>
>
86 5.39 +- 0.44 162.0 +- 6.3 4.26 +- 0.3 5.21 +- 0.34
 
88 1.23 +- 0.27 192.5 +- 6.2 3.0 +- 0.4 3.39 +- 0.38
89 1.38 +- 2.02 161.7 +- 12.6 1.3 +- 0.6 2.18 +- 0.47
90 1.5 +- 1.05 174.4 +- 13.1 3.1 +- 0.5 3.67 +- 0.44
Line: 249 to 273
 
96 1.38 +- 2.02 200.8 +- 13.1 5.12 +- 1.24 5.54 +- 1.37
100 4.96 +- 1.53 201.6 +- 45.5 3.74 +- 1.30 2.52 +- 1.40
Added:
>
>
  • 20130208_0701_lws - problem with this file
 The uncertainty on the sigma from the initial vertical scans is obviously very high (and even unphysical), however, the purpose of this scan is purely to determine the centre vertically for the best horizontal scan and although there is insufficient data for an accurate vertical vertical measurement, the reduced data provides a quick scan and sufficient data to ascertain the vertical centre to within a few microns - adequate for both the horizontal scan and the subsequent non-linear vertical scan.

Added:
>
>
QM14FF Vertical Fit Horizontal Fit Nonlinear using s_ex = horizontal
80 20130208_0614_lws_xy_fit_plot1.png 20130208_0618_lws_xy_fit_plot2.png 20130208_0631_lws_xy_fit_plot2.png
84 20130208_0639_lws_xy_fit_plot1.png 20130208_0643_lws_xy_fit_plot1.png 20130208_0653_lws_xy_fit_plot5.png
86 20130208_0701_lws_xy_fit_plot.png 20130208_0712_lws_xy_fit_plot1.png 20130208_0723_lws_xy_fit_plot2.png
88 20130208_0730_lws_xy_fit_plot1.png 20130208_0732_lws_xy_fit_plot1.png 20130208_0742_lws_xy_fit_plot3.png
89 20130208_0750_lws_xy_fit_plot1.png 20130208_0752_lws_xy_fit_plot1.png 20130208_0802_lws_xy_fit_plot2.png
90 20130208_0810_lws_xy_fit_plot1.png 20130208_0812_lws_xy_fit_plot1.png 20130208_0822_lws_xy_fit_plot2.png
91 20130208_0829_lws_xy_fit_plot1.png 20130208_0832_lws_xy_fit_plot2.png 20130208_0842_lws_xy_fit_plot2.png
92 20130208_0849_lws_xy_fit_plot1.png 20130208_0852_lws_xy_fit_plot1.png 20130208_0902_lws_xy_fit_plot2.png
94 20130208_0910_lws_xy_fit_plot1.png 20130208_0913_lws_xy_fit_plot1.png 20130208_0923_lws_xy_fit_plot2.png
96 20130208_0930_lws_xy_fit_plot1.png 20130208_0939_lws_xy_fit_plot1.png 20130208_1010_lws_xy_fit_plot3.png
100 20130208_1019_lws_xy_fit_plot1.png 20130208_1021_lws_xy_fit_plot1.png 20130208_1031_lws_xy_fit_plot2.png

 
  • quad_LW.png:
    quad_LW.png
Line: 269 to 330
 
  • Laser-wire optics saved - set13feb08_1102.dat
  • Restored previous ATF2 optics set13feb07_19
Added:
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Quad Scan / Shift Analysis

Firstly, having a look at the vertical sigma from both the quick linear vertical scans for centring and the full resolution nonlinear vertical scans. There isn't the clear parabola that one would ideally expect from a quad scan. However, there is an approximate minimum. From the scans above it is clear that the signal to noise ratio is too low near the end of the quad scan - due to degraded laser energy at the end of the shift as well as the accelerator conditions changing as the machine heats up in the day.

Vertical Sigma Vertical Sigma (NL Scans)
20130208_quad_vertical_sigma.png 20130208_quad_nl_vertical_sigma.png

Next, the horizontal sigma. This shows no clear pattern and changes quite dramatically through the quad scan.

Horizontal Sigma
20130208_quad_horizontal_sigma.png

Having a look at the centre of the horizontal and vertical scans, the vertical has a clear and linear sweep in centre throughout the quad scan, however, the horizontal centre shows no clear trend.

Horizontal Centre Vertical Centre (NL Scans)
20130208_quad_horizontal_centre.png 20130208_quad_nl_vertical_centre.png

From this quad scan it is clear that the time for scans must be minimised. The quick vertical scans for alignment produce reasonable results due to the short time they are recorded over and therefore the consistency of experimental conditions. The high resolution nonlinear scans obviously have a lower uncertainty, but this could be even lower if the beam / conditions were more consistent throughout the scan. Swings in charge normalised background can be seen in the raw data for the quad scans (above ones are background subtracted - linear model between first and last 5% of data). This is linked directly with tuning of the linac. The linac energy is unstable on the timescale of about 5 - 15 minutes, which is the approximate timescale for a detailed laser-wire scan. The horizontal laser-wire scans are the longest purely due to the distance required for the chamber to travel. It is unlikely that we can change the behaviour of the linac so therefore we must shorten scan times.

All of this is because there is some dispersion at our location. Changes in the energy affect the size and the position of the beam. Therefore, even without touching the linac during a scan, it will still drift and we'll be sensitive to it. Dispersion must be at least measured and ideally corrected. Furthermore, the beam based alignment wasn't performed so there was a clear drift in position with change in magnet strength.

It is also possible that the beam is coupled coming into the LWIP area. In this case, the quad scan would rotate the beam as well. If the rotation angle is on the order of about 20mrad, the projected beam size by the laser-wire will be almost double its original value - dependent on proportions of electron beam of course and the unknown angle between the laser-wire axis and the nominal electron beam axis

Improvements to be made

  • Software to automatically analyse the quad scan from a list of files for each scan type
  • ControlPlot2 showing cherenkov, cherenkovcn, cherenkovcnbgs, cherenkovcnbgslen
  • Increase horizontal chamber speed to 50um/s - currently 20um/s to at least halve horizontal scan time
  • Don't tune linac during any scan - if transmission drops off - stop scan, fix, repeat scan
  • Perform Dispersion measurement and correction
  • Perform BBA on magnets around us
  • Perform coupling measurement and correction
 

Revision 1014 Feb 2013 - LaurieNevay

Line: 1 to 1
 
META TOPICPARENT name="Atf2LwLogBook"
Line: 236 to 236
  Reanalysis post shift in table below
Changed:
<
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QM14FF Vertical Fit Horizontal Fit NonLinear Using sex = 235.0 Nonlinear using sex = horizontal
80 5.21 +- 0.84 202.2 +- 9.1 6.1 +- 0.3
84 2.29 +- 0.6 138.1 +- 9,3 5.0 +_ 0.3
86 20130208_0701_lws - problem with this file 162.0 +- 6.3 4.26 +- 0.3
88 1.23 +- 0.27 192.5 +- 6.2 3.0 +- 0.4
89 1.38 +- 2.02 161.7 +- 12.6 1.3 +- 0.6
90 1.5 +- 1.05 174.4 +- 13.04 3.1 +- 0.5
91 1.14 +- 1.44 304.04 +- 43.1 3.2 +- 0.5
92 1.86 +- 0.83 150.3 +- 9.0 0.74 +- 0.5
94 2.35 +- 1.05 184.2 +- 9.5 2.11 +- 0.4
96 1.38 +- 2.02 200.8 +- 13.1 5.12 +- 1.24
100 4.96 +- 1.53 201.6 +- 45.5 3.74 +- 1.30
>
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QM14FF Vertical Fit Horizontal Fit NonLinear Using s_ex = 235.0 Nonlinear using s_ex = horizontal
80 5.21 +- 0.84 202.2 +- 9.1 6.1 +- 0.3 6.27 +- 0.33
84 2.29 +- 0.6 138.1 +- 9,3 5.0 +_ 0.3 6.25 +- 0.32
86 20130208_0701_lws - problem with this file 162.0 +- 6.3 4.26 +- 0.3 5.21 +- 0.34
88 1.23 +- 0.27 192.5 +- 6.2 3.0 +- 0.4 3.39 +- 0.38
89 1.38 +- 2.02 161.7 +- 12.6 1.3 +- 0.6 2.18 +- 0.47
90 1.5 +- 1.05 174.4 +- 13.1 3.1 +- 0.5 3.67 +- 0.44
91 1.14 +- 1.44 304.4 +- 43.1 3.2 +- 0.5 2.59 +- 0.58
92 1.86 +- 0.83 150.3 +- 9.0 0.74 +- 0.5 1.91 +- 0.31
94 2.35 +- 1.05 184.2 +- 9.5 2.11 +- 0.4 2.64 +- 0.40
96 1.38 +- 2.02 200.8 +- 13.1 5.12 +- 1.24 5.54 +- 1.37
100 4.96 +- 1.53 201.6 +- 45.5 3.74 +- 1.30 2.52 +- 1.40
  The uncertainty on the sigma from the initial vertical scans is obviously very high (and even unphysical), however, the purpose of this scan is purely to determine the centre vertically for the best horizontal scan and although there is insufficient data for an accurate vertical vertical measurement, the reduced data provides a quick scan and sufficient data to ascertain the vertical centre to within a few microns - adequate for both the horizontal scan and the subsequent non-linear vertical scan.

Revision 913 Feb 2013 - LaurieNevay

Line: 1 to 1
 
META TOPICPARENT name="Atf2LwLogBook"
Added:
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  • Overlap Integral Fits done using 20130205_1627/fit_parameters_input.dat on shift - the previous week's M2.
  • Overlap Integral Fits done using 20130210_1637/fit_parameters_input.dat for post shift analysis of quad scan
 

20130207 Shift

Plans

Line: 231 to 234
 
96 20130208_0930_lws 20130208_0939_lws 20130208_1010_lws
100 20130208_1019_lws 20130208_1021_lws 20130208_1031_lws
Changed:
<
<
QM14FF FilenameV FileNameH FileNameNL
80 5.21 +- 0.84 202.2 +- 9.1 20130208_0631_lws
84 2.29 +- 0.6 138.1 +- 9,3 20130208_0653_lws
86 20130208_0701_lws - problem with this file 162.0 +- 6.3 20130208_0723_lws
88 1.23 +- 0.27 192.5 +- 6.2 20130208_0742_lws
89 1.38 +- 2.02 161.7 +- 12.6 20130208_0802_lws
90 1.5 +- 1.05 174.4 +- 13.04 20130208_0822_lws
91 1.14 +- 1.44 304.04 +- 43.1 20130208_0842_lws
92 1.86 +- 0.83 150.3 +- 9.0 20130208_0902_lws
94 2.35 +- 1.05 184.2 +- 9.5 20130208_0923_lws
96 1.38 +- 2.02 200.8 +- 13.1 20130208_1010_lws
100 4.96 +- 1.53 201.6 +- 45.5 20130208_1031_lws
>
>
Reanalysis post shift in table below

QM14FF Vertical Fit Horizontal Fit NonLinear Using sex = 235.0 Nonlinear using sex = horizontal
80 5.21 +- 0.84 202.2 +- 9.1 6.1 +- 0.3
84 2.29 +- 0.6 138.1 +- 9,3 5.0 +_ 0.3
86 20130208_0701_lws - problem with this file 162.0 +- 6.3 4.26 +- 0.3
88 1.23 +- 0.27 192.5 +- 6.2 3.0 +- 0.4
89 1.38 +- 2.02 161.7 +- 12.6 1.3 +- 0.6
90 1.5 +- 1.05 174.4 +- 13.04 3.1 +- 0.5
91 1.14 +- 1.44 304.04 +- 43.1 3.2 +- 0.5
92 1.86 +- 0.83 150.3 +- 9.0 0.74 +- 0.5
94 2.35 +- 1.05 184.2 +- 9.5 2.11 +- 0.4
96 1.38 +- 2.02 200.8 +- 13.1 5.12 +- 1.24
100 4.96 +- 1.53 201.6 +- 45.5 3.74 +- 1.30
  The uncertainty on the sigma from the initial vertical scans is obviously very high (and even unphysical), however, the purpose of this scan is purely to determine the centre vertically for the best horizontal scan and although there is insufficient data for an accurate vertical vertical measurement, the reduced data provides a quick scan and sufficient data to ascertain the vertical centre to within a few microns - adequate for both the horizontal scan and the subsequent non-linear vertical scan.

Revision 813 Feb 2013 - LaurieNevay

Line: 1 to 1
 
META TOPICPARENT name="Atf2LwLogBook"
Line: 218 to 218
 
  • After each scan, set that axis to its centre
  • Do quads in order to avoid hysteresis or beam wander effects
Changed:
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<
QM14FF FilenameV FileNameH FileNameNL Size
>
>
QM14FF FilenameV FileNameH FileNameNL
 
80 20130208_0614_lws 20130208_0618_lws 20130208_0631_lws
84 20130208_0639_lws 20130208_0643_lws 20130208_0653_lws
86 20130208_0701_lws 20130208_0712_lws 20130208_0723_lws
Line: 231 to 231
 
96 20130208_0930_lws 20130208_0939_lws 20130208_1010_lws
100 20130208_1019_lws 20130208_1021_lws 20130208_1031_lws
Added:
>
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QM14FF FilenameV FileNameH FileNameNL
80 5.21 +- 0.84 202.2 +- 9.1 20130208_0631_lws
84 2.29 +- 0.6 138.1 +- 9,3 20130208_0653_lws
86 20130208_0701_lws - problem with this file 162.0 +- 6.3 20130208_0723_lws
88 1.23 +- 0.27 192.5 +- 6.2 20130208_0742_lws
89 1.38 +- 2.02 161.7 +- 12.6 20130208_0802_lws
90 1.5 +- 1.05 174.4 +- 13.04 20130208_0822_lws
91 1.14 +- 1.44 304.04 +- 43.1 20130208_0842_lws
92 1.86 +- 0.83 150.3 +- 9.0 20130208_0902_lws
94 2.35 +- 1.05 184.2 +- 9.5 20130208_0923_lws
96 1.38 +- 2.02 200.8 +- 13.1 20130208_1010_lws
100 4.96 +- 1.53 201.6 +- 45.5 20130208_1031_lws

The uncertainty on the sigma from the initial vertical scans is obviously very high (and even unphysical), however, the purpose of this scan is purely to determine the centre vertically for the best horizontal scan and although there is insufficient data for an accurate vertical vertical measurement, the reduced data provides a quick scan and sufficient data to ascertain the vertical centre to within a few microns - adequate for both the horizontal scan and the subsequent non-linear vertical scan.

 
  • quad_LW.png:
    quad_LW.png

Revision 710 Feb 2013 - KonstantinKruchinin

Line: 1 to 1
 
META TOPICPARENT name="Atf2LwLogBook"
Line: 231 to 231
 
96 20130208_0930_lws 20130208_0939_lws 20130208_1010_lws
100 20130208_1019_lws 20130208_1021_lws 20130208_1031_lws
Added:
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  • quad_LW.png:
    quad_LW.png
 
  • Log on collisions with charge varied
  • Log on collisions with laser energy varied
  • Log with no laser for background
Line: 240 to 244
  Corresponding OTR quad scan to LW scan. Three samples at each point. Repeat in same order as laser-wire.
Added:
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  • quad_OTR.png:
    quad_OTR.png
 
  • Laser-wire optics saved - set13feb08_1102.dat
  • Restored previous ATF2 optics set13feb07_19
Line: 259 to 270
 
META FILEATTACHMENT attachment="20130208_0253_lws_xy_fit_plot.png" attr="" comment="Vertical Scan at Horizontal Centre" date="1360260676" name="20130208_0253_lws_xy_fit_plot.png" path="20130208_0253_lws_xy_fit_plot.png" size="56875" stream="20130208_0253_lws_xy_fit_plot.png" user="Public.LaurieNevay" version="1"
META FILEATTACHMENT attachment="20130208_0149_lws_xy_errbar_plot.png" attr="" comment="Vertical Alignment" date="1360260718" name="20130208_0149_lws_xy_errbar_plot.png" path="20130208_0149_lws_xy_errbar_plot.png" size="31061" stream="20130208_0149_lws_xy_errbar_plot.png" user="Public.LaurieNevay" version="1"
META FILEATTACHMENT attachment="20130208_0243_lws_xy_fit_plot.png" attr="" comment="LW Horizontal Scan" date="1360260930" name="20130208_0243_lws_xy_fit_plot.png" path="20130208_0243_lws_xy_fit_plot.png" size="56868" stream="20130208_0243_lws_xy_fit_plot.png" user="Public.LaurieNevay" version="1"
Added:
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META FILEATTACHMENT attachment="quad_scan_1.eps" attr="" comment="" date="1360458032" name="quad_scan_1.eps" path="quad_scan_1.eps" size="67108" stream="quad_scan_1.eps" user="Public.KonstantinKruchinin" version="1"
META FILEATTACHMENT attachment="quad_LW.png" attr="" comment="" date="1360458322" name="quad_LW.png" path="quad_LW.png" size="31397" stream="quad_LW.png" user="Public.KonstantinKruchinin" version="1"
META FILEATTACHMENT attachment="quad_OTR.png" attr="" comment="" date="1360458470" name="quad_OTR.png" path="quad_OTR.png" size="44308" stream="quad_OTR.png" user="Public.KonstantinKruchinin" version="1"

Revision 608 Feb 2013 - LaurieNevay

Line: 1 to 1
 
META TOPICPARENT name="Atf2LwLogBook"
Line: 131 to 131
 

01:30 LW

  • Positions saved after OTR and before LW alignment - 20130208_0126_pos.dat
Added:
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>

02:00 Alignment

  • Set manipulator to 8820 (where laser was before)
  • Vertical & Horizontal scans with chamber -> look at wire-scanner detector
  • Set V:185, H:250
  • Timing ok - Set voltage to 5.0V
 
Added:
>
>
Horizontal Alignment Vertical Alignment
20130208_0158_lws_xy_errbar_plot.png 20130208_0149_lws_xy_errbar_plot.png
 
Added:
>
>
Phase Scan
 
Added:
>
>
  • Initial scan - collisions!
  • Within 20um of aligned position.
  • Signal:Background ~ 1:8 so not great, but visible
  • Laser energy downstairs is estimated to be 33mJ post-ip although this is a slight underestimate
  • Comparing to previous shift, signal to background is approximately the same accounting for lower laser energy
 
Added:
>
>
20130208_0224_lws_xy_fit_plot.png
 
Added:
>
>
Laser-wire Vertical Scan
 
Changed:
<
<

Laser-wire Startup

Data Synchronicity

Laser-wire Angular Dependence

Scans

The Almighty LW Quad Scan

The Almighty OTR Quad Scan

>
>
20130208_0253_lws_xy_fit_plot.png

Laser-wire Horizontal Scan

20130208_0243_lws_xy_fit_plot.png

Laser-wire Phase Scan

20130208_0303_lws_xy_fit_plot.png

Phase scan suggested a voltage of 4.47V and we set to that. Then repeated vertical scan, but signal vastly reduced. Setting back to original 5.0V and rescanning vertical.

  • Charge dropping off - Mod #2 very sensitive. Alex retuning linac
  • Signal was dropping off despite returning to same position - not clear what's happening
  • Laser energy the same both before and after LWIP (photodiode & laseren)

  • Phase, Horizontal, Vertical again...

  • Phase set to 4.74V, Horizontal set to 62. Vertical scan nonlinear about chaver:151, 60 points, 20 samples
  • Vertical scan quite good!!! Shows 1.7 +- 0.23um. Larger size before must have been due to horizontal offset.
  • Amplitude 0.72 vs background 4.2

Horizontal Slicing

 
Added:
>
>
  • Centre is chahor:62
  • Using cherenkovcnbgslen
 
Added:
>
>
ChaHor Filename Size
62 (centre) 20130208_0418_lws 1.71 +- 0.26um
72 20130208_0437_lws 0.73 +- 0.23um
82 20130208_0453_lws 1.73 +- 0.25um
92 20130208_0504_lws 1.23 +- 0.18um

* Not showing clear dependence -> step size too small. Also better to take a few scans at each location.

* 62, +-50, +-100 -> 3 scans as each location

ChaHor Filename Size
62 20130208_0418_lws 1.71 +- 0.26um
62 20130208_0517_lws 2.35 +- 0.16um
62 20130208_0527_lws 2.63 +- 0.18um
72 20130208_0536_lws 1.50 +- 0.2um  

*set file: set13feb080608.dat

LW Quad Scan

  • Vertical Linear - 20 steps - 10 samples - +-20um
  • Horizontal Linear - 30 steps - 20 samples - +-700um
  • Vertical Nonlinear - 50 steps - 20 samples - default range

  • Repeat above pattern for each quad setting.
  • After each scan, set that axis to its centre
  • Do quads in order to avoid hysteresis or beam wander effects

QM14FF FilenameV FileNameH FileNameNL Size
80 20130208_0614_lws 20130208_0618_lws 20130208_0631_lws
84 20130208_0639_lws 20130208_0643_lws 20130208_0653_lws
86 20130208_0701_lws 20130208_0712_lws 20130208_0723_lws
88 20130208_0730_lws 20130208_0732_lws 20130208_0742_lws
89 20130208_0750_lws 20130208_0752_lws 20130208_0802_lws
90 20130208_0810_lws 20130208_0812_lws 20130208_0822_lws
91 20130208_0829_lws 20130208_0832_lws 20130208_0842_lws
92 20130208_0849_lws 20130208_0852_lws 20130208_0902_lws
94 20130208_0910_lws 20130208_0913_lws 20130208_0923_lws
96 20130208_0930_lws 20130208_0939_lws 20130208_1010_lws
100 20130208_1019_lws 20130208_1021_lws 20130208_1031_lws

  • Log on collisions with charge varied
  • Log on collisions with laser energy varied
  • Log with no laser for background

OTR Quad Scan

Corresponding OTR quad scan to LW scan. Three samples at each point. Repeat in same order as laser-wire.

  • Laser-wire optics saved - set13feb08_1102.dat
  • Restored previous ATF2 optics set13feb07_19
 

Deleted:
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META FILEATTACHMENT attachment="focus.jpg" attr="" comment="OTR Focus Scan" date="1360255375" name="focus.jpg" path="focus.jpg" size="713590" stream="focus.jpg" user="Public.KonstantinKruchinin" version="1"
META FILEATTACHMENT attachment="quad.jpg" attr="" comment="" date="1360255502" name="quad.jpg" path="quad.jpg" size="644260" stream="quad.jpg" user="Public.KonstantinKruchinin" version="1"
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META FILEATTACHMENT attachment="20130208_0158_lws_xy_errbar_plot.png" attr="" comment="Horizontal Alignment" date="1360259924" name="20130208_0158_lws_xy_errbar_plot.png" path="20130208_0158_lws_xy_errbar_plot.png" size="30039" stream="20130208_0158_lws_xy_errbar_plot.png" user="Public.LaurieNevay" version="1"
META FILEATTACHMENT attachment="20130208_0224_lws_xy_fit_plot.png" attr="" comment="Phase Scan in APD" date="1360260048" name="20130208_0224_lws_xy_fit_plot.png" path="20130208_0224_lws_xy_fit_plot.png" size="50830" stream="20130208_0224_lws_xy_fit_plot.png" user="Public.LaurieNevay" version="1"
META FILEATTACHMENT attachment="20130208_0303_lws_xy_fit_plot.png" attr="" comment="LW Phase Scan" date="1360260635" name="20130208_0303_lws_xy_fit_plot.png" path="20130208_0303_lws_xy_fit_plot.png" size="52676" stream="20130208_0303_lws_xy_fit_plot.png" user="Public.LaurieNevay" version="1"
META FILEATTACHMENT attachment="20130208_0253_lws_xy_fit_plot.png" attr="" comment="Vertical Scan at Horizontal Centre" date="1360260676" name="20130208_0253_lws_xy_fit_plot.png" path="20130208_0253_lws_xy_fit_plot.png" size="56875" stream="20130208_0253_lws_xy_fit_plot.png" user="Public.LaurieNevay" version="1"
META FILEATTACHMENT attachment="20130208_0149_lws_xy_errbar_plot.png" attr="" comment="Vertical Alignment" date="1360260718" name="20130208_0149_lws_xy_errbar_plot.png" path="20130208_0149_lws_xy_errbar_plot.png" size="31061" stream="20130208_0149_lws_xy_errbar_plot.png" user="Public.LaurieNevay" version="1"
META FILEATTACHMENT attachment="20130208_0243_lws_xy_fit_plot.png" attr="" comment="LW Horizontal Scan" date="1360260930" name="20130208_0243_lws_xy_fit_plot.png" path="20130208_0243_lws_xy_fit_plot.png" size="56868" stream="20130208_0243_lws_xy_fit_plot.png" user="Public.LaurieNevay" version="1"

Revision 507 Feb 2013 - KonstantinKruchinin

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META TOPICPARENT name="Atf2LwLogBook"
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  • Horizontal (otr switch) scan with focus scan at each location
  • Focus Scan
initial position ip:otrlens:z 14.25000, scan range: 12.4 - 14.4, step: 0.1 mm, best position - 13.4000
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  • OTR Focus Scan:
    focus.jpg
 
  • Quad Scan
scan range QM14FF: -80 - -100 A, step 2.5 A, best position: -89.37171
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  • quad.jpg:
    quad.jpg
 
QM14FF Current
-80.0
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META FILEATTACHMENT attachment="focus.jpg" attr="" comment="OTR Focus Scan" date="1360255375" name="focus.jpg" path="focus.jpg" size="713590" stream="focus.jpg" user="Public.KonstantinKruchinin" version="1"
META FILEATTACHMENT attachment="quad.jpg" attr="" comment="" date="1360255502" name="quad.jpg" path="quad.jpg" size="644260" stream="quad.jpg" user="Public.KonstantinKruchinin" version="1"

Revision 407 Feb 2013 - LaurieNevay

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META TOPICPARENT name="Atf2LwLogBook"
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  • Laser-wire signal attenuation was 9dB last week to take best advantage of ADC range. Typical background level was 8800 ADC counts.
  • Changed attenuation to 14dB - aim for 5000 ADC counts background with this attenuation or lower.
Deleted:
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OTR

Added:
>
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  • Horizontal (otr switch) scan with focus scan at each location
  • Focus Scan
initial position ip:otrlens:z 14.25000, scan range: 12.4 - 14.4, step: 0.1 mm, best position - 13.4000
  • Quad Scan
scan range QM14FF: -80 - -100 A, step 2.5 A, best position: -89.37171

QM14FF Current
-80.0

01:30 LW

  • Positions saved after OTR and before LW alignment - 20130208_0126_pos.dat

 

Laser-wire Startup

Data Synchronicity

Laser-wire Angular Dependence

Revision 307 Feb 2013 - LaurieNevay

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On Shift

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The Best Laid Plans...

Laser build up time had increased yesterday, but not significantly. I have avoided using the laser due to damage on the etalon and this only gets worse with use. Today, the build up time was much longer again. The maximum output from the regen is 4mJ, which is very low. Slight tweaks really didn't improve it at all. Tried various pockel's cells timing, but no improvement. Removed etalon and unseeded regen output is 17mJ, which is down from last week's 24mJ. So, likely cavity is also degrading, but still expect around 12/24mJ (with etalon / without etalon - last week) out, which would be around 8.5mJ with etalon.

Further damage is evident on the etalon in the new position and there isn't much space to move the laser beam anywhere else.

So, current regen output around 4.2mJ. Maximum output from laser around 70mJ upstairs.

Took access and checked alignment downstairs - corrected slightly. Tweaked green upstairs on energy meter.

 

Optics

Changed:
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PLIC Detector

>
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Loading set file ***.dat. Changing magnets QM15,14,13,12FF.

  • Laser-wire signal attenuation was 9dB last week to take best advantage of ADC range. Typical background level was 8800 ADC counts.
  • Changed attenuation to 14dB - aim for 5000 ADC counts background with this attenuation or lower.
 

OTR

Laser-wire Startup

Data Synchronicity

Revision 207 Feb 2013 - LaurieNevay

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META TOPICPARENT name="Atf2LwLogBook"
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20130207 Shift

Plans

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Accelerator

  • SAVE OPTICS!!!!
  • Increase charge to ideally between 0.7 and 1.0
  • Spend a little time to optimise linac / transport for higher charge and stability

Optics

  • Load Lw optics
  • Upstream steering to minimise background (before FF)
  • Vertical Dispersion measurement / correction at LWIP - using Glen's FS tool. Measure after correction as well to verify - sometimes takes more than once
  • Coupling correction - using upstream OTRs?
  • Steer to centre of QM16FF
  • BBA QM16,15,14,13 and 12FF - manual or using Glen's FS tool
  • Most importantly 14, then 15, but ideally both.
  • Reduce ipangle to < 100urad in both dimensions
  • Check background

OTR

  • Verify vertical beam size
  • Quick quad scan to optimise QM14FF strength
  • Update horizontal size in EDM

CBPM Resolution Logs

  • Move chamber until MFB2FF not saturated - ie at minimum ADC counts - use CBPM panel
  • Log 5 sets of CBPM data using CBPM EDM - 500 pulses per set - for resolution measurements
  • Vertical Dispersion measurement / correction at LWIP - using Glen's FS tool. Measure after correction as well to verify - sometimes takes more than once

Laser-wire Startup

  • Spatial Alignment
  • Temporal Alignment
  • Optimise, Vertical, Phase, Horizontal; repeat.

  • Charge ramp - Log 1000 pulses on collisions
  • Laser ramp - Log 1000 pulses on collisions
  • Charge ramp - Log 1000 pulses off collisions (ie laser off but same position)
 

PLIC Detector

  • Turn up vertical scale on PLIC and compare laser on laser off on collisions - anything at all?
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Data Synchronicity

  • While on collisions, block laser beam upstairs for a couple of pulses; repeat about 10 times in 500 pulse log
  • Use single shot mode of accelerator to fire one electron bunch during say 500 pulse log; repeat about 10 times
  • Check syncrhonicity of refc1amp, cherenkov, laserenergy, photodiode

Laser-wire Angular Dependence

  • Back on collisions
  • Move QM14FF on movers slightly to affect angle at LWIP - need to make large steps in angle +- 200urad in angle
  • Compare laser on, laser off signal to background ratio at each point with two separate logs

Scans

  • check optimisation of laser-wire via
  • Phase scan
  • Long range horizontal -2200 -> +2200 chahor, 80 steps, 15 samples at each
  • Vertical scan - usual - 70 points, 20 samples
  • Vertical scans at +- 25um, 50um, 75um, 100um horizontally - may need to use linear scan for larger ones at sides as nonlinear too narrow

MFB2FF Alignment

  • Save positions for optimal laser-wire position - 100 pulse log (for bpm information)
  • Move chamber for best MFB2FF position
  • Save positions here - 100 Pulse Log

The Almighty LW Quad Scan

  • NOTE quad scan should go in order - NOT middle first, then out, to avoid hysteresis or drift of accelerator effects in results
  • Save accelerator set file at beginning!!! for e beam modelling purposes!
  • 11 point quad scan
  • Centre +- 1,2,3,5,7A on QM14FF
  • At each point:
  • Horizontal scan -2000 -> + 2000, 50 points, 10 samples -> move to centre at end
  • Small linear vertical scan to centre properly
  • Nonlinear vertical scan - 70 points, 15 samples

The Almighty OTR Quad Scan

  • Repeat above quad scan, but with OTR images
  • 3 samples at each magnet current

RELOAD OPTICS

  • Save our optics!
  • Quads
  • Steering
  • Optics save again

On Shift

Optics

PLIC Detector

OTR

Laser-wire Startup

Data Synchronicity

Laser-wire Angular Dependence

Scans

The Almighty LW Quad Scan

The Almighty OTR Quad Scan

 
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Settings just to customise this page

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Revision 105 Feb 2013 - LaurieNevay

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META TOPICPARENT name="Atf2LwLogBook"

20130207 Shift

Plans

PLIC Detector

  • Turn up vertical scale on PLIC and compare laser on laser off on collisions - anything at all?
 
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