| ID |
Date |
Author |
Category |
Subject |
|
102
|
Tue Apr 5 20:58:53 2022 |
Wilfried | Laser | Trigger for Laser |
Electronic for the timing of the laser puls optimized. The problem with the broad photodiode histograms is solved.
The photo of the oscilloscope picture shows in magenta the pulses from the (discriminated RF)/2, in yellow the pulses that are generated to open the Q-Switch. The latter are generated by the coincidence of the 30-Hz trigger (2 microsec long) to
allow for the Q-Switch to be fired. Within this period are usually 2 pulses from the RF and both generate a 100 ns long coincidence puls. The first one of those creates a 50 microsec long window (light blue) that is send to the Q-switch. The length
and the delay of this pulse can be changed. While the length is kept fixed, the delay can be changed in order to shift the arrival time of the laser pulse at the electron cooler to coincide with the ion bunch.
The problem of the wide photodiode histograms and the background was caused by a too large pulsewidth of the discriminated RF. The magenta pulses were about 100 ns long. Any pulse that arrives within a timespan between 99 and 0 ns before the 30-Hz
trigger of the Q-switch "allowance" will trigger a laser pulse immediately at the start of this trigger and therefore a jitter of up to 100 ns can occur. Therefore it is important that the CFD pulses are as short as possible, we set them to 20 ns
and the width of the photodiode histogram was just 3 bins wide (at the foot maybe 5 bins).
I (Rodolfo) just added the picture with the cabling configuration. The colors of cables match together with the colors show in the oscilloscope. |
| Attachment 1: TriggerForLaser_05-04-2022.PNG
|
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| Attachment 2: TriggerLaser_Cabling.jpg
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148
|
Fri Apr 8 02:14:05 2022 |
Wilfried | Laser | Laser timings adjusted |
Since we use the middle window as a reference for the laser pulse timing, the fact that the window is 2.25 m behind the target has to be taken into account. From here the ions have 10 ns less time of flight to the middle of the electron cooler than they need for half a revolution. The signals were still symmetrically aligned around the reference bunch as it was done yesterday. Therefore, the delay of the laser pulse was reduced by 10-ns on the oscilloscope, which led both photodiode histograms move 3 bins further to the right (towards larger times till common stop, since the pulse arrives earlier).
Since the RF frequency is turned down from ~ 1 MHz to ~ 400 kHz during injection/preparation, the laser does not fire reliably and the beam stabilization does not work very well during this period. This was solved by increasing the window in which the Q-Switch signal is accepted from 2 microseconds to 5 microsececonds. The laser is now firing regularly and with high power also during the preparation time and the beam position stabilization works very well. |
|
164
|
Fri Apr 8 14:43:50 2022 |
Wilfried | DAQ | laser timing - Q-switch start |
below are my notes concerning laser timing / Q-switch start |
| Attachment 1: IMG_20220408_143753_resized_20220408_023840170.jpg
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168
|
Fri Apr 8 15:45:24 2022 |
YL | | Spectrum manipulation 5 |
See attached |
| Attachment 1: IMG_3027.JPG
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68
|
Sat Apr 2 18:17:31 2022 |
Yuri | Accelerator | Photo-Identification |
Just a photo of the ID |
| Attachment 1: 9FFA52AA-1F75-470E-AD1B-E1A612A3F7D6.jpeg
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69
|
Sat Apr 2 18:19:47 2022 |
Yuri | Accelerator | Scraping |
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| Attachment 1: trim.3539D818-8003-4093-866E-2C4F619E614F.MOV
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167
|
Fri Apr 8 15:42:20 2022 |
Yuri | Accelerator | Slits in the TE line |
At around 15:00, The slits in the TE line were changed to :
TE4DS5HL -12 mm -> -20 mm
TE5DSAH 0 mm -> +15 mm |
|
131
|
Thu Apr 7 08:14:03 2022 |
Yuri & Danyal | General | 229Th89+ line in Schottky |
GLOBAL calculations for the "content" of the Th line in the Schottky spectrum
(380 MeV/u exit energy, equilibrium charge state distribution)
Actinium 9.9% - bare
Thorium 42.4% - H-like
Protactinium 44.8% - He-like
Uranium 2.7% - Li-like |
|
74
|
Sun Apr 3 10:28:25 2022 |
Yuri (Helmut Weick) | Accelerator | Distance cooler - detector |
Calculation from Helmut Weick
Distance e-cooler to particle detectors chamber:
“This is half of ESR plus distance target - detector. This even is on the web page”
54.28 m + 21.64 m |
|
75
|
Sun Apr 3 10:35:20 2022 |
Yuri (Sergey) | Accelerator | Dipole correction |
The ramp for moving the beam to the central orbit
To be inserted into manipulation, GE01MU1 (SC 5): 1.05969755 rad
This can be done only when one stays in the manipulation 5
Afterwards “Manipulieren” and not “An Geräte schicken” |
|
166
|
Fri Apr 8 15:39:36 2022 |
all | Runs | first data after timing set up |
started taking data again
started at 15:40
h=1
file names
229Th7821 DAQ 1 607 MB
229Th0082 DAQ 2 820 MB
stopped at 16:25
The laser was not really properly scanned.
This was mainly a test run to see if everything was working. |
|
121
|
Thu Apr 7 02:32:29 2022 |
all on shift | Runs | First Scans 322-320nm |
Laser scanning from 322-320 steps 0.01nm/s
DAQ1: lxg1927:/data.local2/BeamTimeTh22/
DAQ2: lxg0155:/data.local2/E142/
LMD file name DAQ1:229Thor
LMD file name DAQ2:229Th
|
Time | SIS-intensity | cooler-HV | LMD-DAQ1 | LMD-DAQ2
| |
02.30 | ? | ? | Th227781-Th227784 | 0027-0028
| |
03.03 | 1.75e9 | 209648 | 7785-7787 | 0029-0030
| |
03:28 | 1.7e9 | 209648 | 7788 | 0031 (stopped during scan)
| |
Break - fixing cables, Elog ID: 125
| |
04:00 - problems with UNILAC, stopping for now.
| |
Apparently not so bad problems. we can continue.
| |
Mesytek PS of xuv-detector crashed, can only be restarted from inside the ESR by turning the crate on and off.
| |
05.20 | 1.23e9 | 209646 | 7791-7794 | 0035-0038
| |
05.52 | 1.5e9 | 209648 | 7795-7797 | 0039-0042
| |
06.24 | 1.5e9 | 209642 | 7798-7800 | 0043-0046 | 1 sec waiting at each laser frequency (dwell time 30)
| |
07.36 | xx e9 | 209 xx | 7803-7804 | 0047-0050 | problems with DAQ 1 and DAQ2
| |
07.52 | xx e9 | 209646 | 7805-7809 | 0051-0055 | DAQs started again | 5 sec waiting at each laser frequency (dwell time 150)
| |
08.30 | e9 | 209 xx | 7810-78 | 0056-00 | DAQs started again | 5 sec waiting at each laser frequency (dwell time 150)
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162
|
Fri Apr 8 14:12:57 2022 |
morning shift | DAQ | timing for h=1 |
The timing for h=1 has been set up
The time window is now twice as large as before!
This means that we see the same ion bunch twice.
(150 bins = 1 turn in the ESR)
The PMT signal is exactly in between two cycles + the extra flight time (3 bins = 10 ns) from target to PMT north. |
| Attachment 1: 2022-04-08_timing_h1_final.png
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