2023-03-20
Machine Status
Vacuum is 2.3e-7 Pa (Friday was 3.8e-7).
TORA signal is greater than around ±80 mV at injection. Similar to Friday.
FAB signal is much larger, and requires 1 V/div for the bunched region.
Equipment
We have added the ability to remotely control the horizontal scale of the scope. This works by setting the horizontal time/ division and then setting the maximum sample rate to fill the scope's memory. We tested this a few times before we started any measurements and found no problems.
Measurements and Today's Plots
Measurements will have the same case description as on Friday (see image below).
For all cases we will (at least) acquire at:
Flat-top during debunch
Coasting
Flat-top during recapture
We will acquire:
5 Beam-on datasets
2 Beam-off datasets
The primary aim of today is to take measurements with a range of beam energy gaps, which refers to the gaps between the centres of the Schottky peaks.
Measurement 1 - Case 1 - Repeat of Friday (Old RF Pattern)
The AWGScript's have a 1 ms flat-top at ~10.9 ms. The two combined AWGScripts for this experiment are shown below. 175 keV separation with 0.9 kV RF.
General Scope Settings:
50 ms total time window (5 ms/div)
500 MSa/s
50 mV/ div for coasting
1 V/ div for bunched
1 MOhm Termination on FAB Amp
50 Ohm Termination on RF Amp
Debunch
Recapture
File 0 contains an error, as the second injected beam was still being injected, but wasn't captured.
File 1 is the first beam-on dataset with a delay of 25 ms.
The second datasets were with 121 ms delay. At this point, we verified that the Schottky signal was still there. It was clearly visible above the beam-off noise, and a similar height to Friday.
The third datasets were with 272 ms delay for a later coast.
The fourth datasets were with 360 ms delay for the recapture. The beam went off unexpectedly, so several beam-on datasets had a no-beam signal. All datasets for this delay time were repeated (all 5 beam-on and 2 beam-off).
Figure: 121 ms delay
Measurement 2 - Case 4 New RF Pattern (6.98 ms) - 165 keV Gap
Debunch
Recapture
The first group of datasets have delay set to 25 ms.
The second group of datasets have delay set to 122 ms. This has moved by 1ms compared to the previous measurement because the flat-top on this script is 1 ms, whilst it was 2 ms on the previous files.
The third group of datasets have a delay setting of 273 ms. The beam went off unexpectedly, so several beam-on datasets had a no-beam signal. All datasets for this delay time were repeated (all 5 beam-on and 2 beam-off).
The fourth group of datasets have a delay setting of 360 ms.
The fifth group is an extra set of data acquired with a delay of 200 ms. We did this to have an extra point to verify that the lifetime is decreasing slowly throughout the coasting time.
Figure: 122ms delay
Measurement 3 - Case 4 New RF Pattern (7.00 ms) - 95 keV Gap
Debunch
Recapture
First group of datasets with 25 ms delay (1 V/div)
Second group of datasets with 122 ms delay (50 mV/ div)
Third group of datasets with 200 ms delay (50 mV/div)
Fourth group of datasets 273 ms delay (50 mV/div)
Fifth group of datasets 360 ms delay (1 V/ div)
Figure: 122 ms delay
Measurement 4 - Case 4 New RF Pattern (7.02 ms) - 24 keV Gap
Debunch
Recapture
First group of datasets with 25 ms delay (1 V/div)
Second group of datasets with 122 ms delay (50 mV/ div)
Third group of datasets with 200 ms delay (50 mV/div)
Fourth group of datasets 273 ms delay (50 mV/div)
Fifth group of datasets 360 ms delay (1 V/ div)
Measurement 5 - Case 4 New RF Pattern (6.99 ms) - 130 keV Gap
Debunching
Recapture
First group of datasets with 25 ms delay (1 V/div)
Second group of datasets with 122 ms delay (50 mV/ div)
Third group of datasets with 200 ms delay (50 mV/div)
Fourth group of datasets 273 ms delay (50 mV/div)
Fifth group of datasets 360 ms delay (1 V/ div)
Measurement 6 - Case 4 New RF Pattern (6.96 ms) - 235 keV Gap
First group of datasets with 25 ms delay (1 V/div)
Second group of datasets with 128 ms delay (50 mV/ div)
There was a problem with this data. When the scope was set to 100 mV/div we saw a periodic drop of the signal originating from the time around injection, which sometimes meant that the signal clipped. A screenshot of the drop is below. The signal only appeared when the beam was on. The signal also only appeared when the scope vertical vision was set to 200 mV/divison, so we went to the accelerator hall and rebooted the scope. This did not seem to fix the problem, so we just changed the delay of this dataset.
Third group of datasets with 200 ms delay (50 mV/div)
Fourth group of datasets 273 ms delay (50 mV/div)
Fifth group of datasets 360 ms delay (1 V/ div)
Debunch
Rebunch
Measurement 7 - Case 4 New RF Pattern (6.97 ms) - 200.6 keV Gap
First group of datasets with 25 ms delay (1 V/div)
Second group of datasets with 128 ms delay (50 mV/ div)
Delay is different to earlier measurements. See Measurement 6 for reason.
Third group of datasets with 200 ms delay (50 mV/div)
Fourth group of datasets 273 ms delay (50 mV/div)
Fifth group of datasets 360 ms delay (1 V/ div)
Debunch
Recapture
Measurement 8 - Case 4 New RF Pattern (6.975 ms) - 182.5 keV Gap
First group of datasets with 25 ms delay (1 V/div)
Second group of datasets with 128 ms delay (50 mV/ div)
Delay is different to earlier measurements. See Measurement 6 for reason.
Third group of datasets with 200 ms delay (50 mV/div)
Fourth group of datasets 273 ms delay (50 mV/div)
Fifth group of datasets 360 ms delay (1 V/ div)
Debunch
Recapture
Summary Plot
