ID |
Date |
Author |
Category |
Subject |
84
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Mon May 17 21:43:56 2021 |
Danyal | General | The test beamtime was a success. |
Dear all,
The test beamtime is now over.
We had 6 days of Li-like carbon in the ESR (122 MeV/u).
Effectively, we could measure almost 5 days continuously.
There were only a few interruptions, one of which was a longer power failure.
The vacuum in the ESR was not optimal, which strongly reduced the lifetime of the stored ion beam (~30 s)
and the electron cooler showed weird instabilities, which need to be clarified still.
Still, we were able to cover all aspects of the program.
Essentially everything we tried worked.
Therefore, I conclude that it was a great success.
Many thanks to all who have contributed to it!
Special thanks to Sebastian and Benedikt - who worked really hard during the last months - for prepapring the laser system and the data acquisition system.
Also special thanks to Volker and Ken for preparing the XUV detector system.
We will start sorting/ordering & filtering the data soon and will invite for a meeting where we present the raw data so that we can discuss it.
Then we will also discuss the next big step: data analysis.
Of course it is our next objective (with high priority) to publish the analyzed data in foreseeable time.
I hope to see you soon.
Until then, take care and stay healthy,
Danyal |
Draft
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Wed May 12 02:16:25 2021 |
Danyal, Lars | Accelerator | Ion beam position |
Laser Position with scrapers verified.
1HA: impossible to scratch laser beam, still there at -1.0 mm
2HA: +3mm --> half the laser power on detector; +4.5mm --> gone
2VO: interlock, impossible to move (beam diagnostics is informed and will check)
1VO: +0.2mm --> half laser power, +1.2: laser gone (-1.0mm: also gone)
Ion beam adapted to measured laser beam, Target bump position: -22mm (was -18mm before)
Ion beam position verified with scrapers:
1HA: -1.0mm --> still there
2HA: +4.0mm --> beam gone
Target bump angle: unchanged (+1.2 mrad) |
66
|
Sat May 15 09:57:24 2021 |
Dayshift | Runs | Currently on schedule |
Enhance fluorescence rate and perform
laser bunch timing
Right now: Performing several detector tests with scanning laser (triangle) between 1028.930 and 1028.950 nm. Eccoler current @ 10 mA |
85
|
Tue May 31 07:29:11 2022 |
Ken | Detectors | XUV-Detektor |
Rate was very low: ~ 100Hz
Adjusted Walk level and Threshold, new rate: 5kHz
Additionally, parameters of the detector were varied for optimization but were returned to default afterwards. |
4
|
Tue May 11 16:33:31 2021 |
Ken Ueberholz | Detectors | Detector control manual |
Attached to this elog entry is a short manual for the xuv-detector control. If anything is missing or not understandable I can change anything. |
Attachment 1: Manual.pdf
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22
|
Wed May 12 18:59:15 2021 |
Ken Ueberholz | General | Power is back |
Power is back and most things are running again |
24
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Wed May 12 22:28:55 2021 |
Ken Ueberholz | General | Bunching succesfull |
Bunching with 2 and 10 bunches succesfull |
28
|
Wed May 12 23:36:18 2021 |
Ken Ueberholz | DAQ | VI change |
carbon main vi - kopie is now in operation
here, in keysight.vi the input settings for the new impedence for the multimeter are now hopefully correct --> THIS SHOULD BE CHECKED IF THE RING IS OPEN |
29
|
Wed May 12 23:45:23 2021 |
Ken Ueberholz | General | Laser does not reach the exit window |
High rates on the detector at 50mm positions, laser does not seem to reach the exit window. |
39
|
Thu May 13 18:34:54 2021 |
Ken Ueberholz | General | What happened scince shift change at 4pm |
Ion frequency shifts with laser, both manually and scanned, without bunches: successful
Bunching with 7 and 20 bunches: successful
Tried laser scans with bunches: unsuccessful
Manual laser scans with bunches: successful |
42
|
Thu May 13 23:42:37 2021 |
Ken Ueberholz | General | What was done |
In this shift a number of successful Schottky measurements were done:
With fixed laser wavelength, while varying the wavelength, with different bunching and more (see logfile 1 for more info: line 53 to at least 107).
The detector software sometimes files to change the current of the power supplies, if this happens a simple restart of the GUI fixes the problem.
Once in this shift the Mesytek in the laser lab turned itself (?) off and the background rate increased. Hopefully this was a single event. |
Attachment 1: Schottky1.jpeg
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Attachment 2: Schottky2.jpeg
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Attachment 3: Schottky3.jpeg
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Attachment 4: Schottky4.jpeg
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Draft
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Wed May 12 09:05:48 2021 |
Keysight Settings | DAQ | |
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10
|
Wed May 12 08:10:17 2021 |
Lars | General | instabilities in ion frequency |
looks like the E-Cooler is responsible for this. If one turns off the electron current, the beam stays stable.
M.Steck is informed.
> The ion beam moves around, pretty arbitrary. See picture.
> ESR crew believes that it is not due to fluctuations in the HV of the E-Cooler. |
18
|
Wed May 12 10:14:18 2021 |
Lars | Accelerator | E-Cooler |
M.Steck et al. discussed about the E-Cooler and found a possible issue. They asked for enterance to the ESR. Since nobody else was in the HKR and anyway nothing was running because of some other issues, I told, the experiment would not be disturbed and they could enter and do things. (Sth. like putting some repeller electrodes onto hand and other magical things).
It should take about 10 Minutes and might be already finished by now. |
38
|
Thu May 13 03:35:25 2021 |
Lars | General | Status: Current schedule ... so far |
1.) so far:
h = 2, 4, 6, 7, 8, 10, 12, 14, 16, 18, 20, 30
Amplitudes: (10, 50, 100, 150, 200, 250) mV
now we will try to use the laser-toy ;-)
> 1.) check h=2,4,6,7,8,10 .... bunching frequencies with different amplitudes (signalgenerator), Ecooler ON, Laser OFF --> record schottky and "normal" DAQ
>
> 2.) Ecooler ON, Bunching ON, Laser ON (wavelength fixed and/or scanned)
>
> 2.1) Do we see the laser in the Schottky? (The laser has to be on the right side of the bunches and act as a barrier to damp the oscillation of the ions inside the buckets.)
> If not change laser wavelength until we see the laser in the schottky
>
> 2.2) Do we see fluorescence in the XUV Detector signal? Weak fluorescence signal --> check laser-bunch timing by varying the lead delay until we see the highest fluorescence signal.
> If we see no fluorescence signal change laser wavelength until we see fluorescence from the xuv anode signal.
>
> 3.) Do we see that some sidebands vanish in the schottky? Does the lifetime of the ion beam increase?
> 3.1.) If not "play" with Laserparameters, scans, delays, etc... |
62
|
Sat May 15 06:51:16 2021 |
Night Shift Sebastian/Max/Noah | General | Different Laserscantypes |
We use different scan types (manual scan) or constant laser wavelengths to check the effects of laser cooling in the Schottky diagrams (fluorescence can not be seen in the detector), for different bunching amplitudes and frequencies:
- Scan from 1028.950 -> 1028.940, stepsize 0.001 every 10 sec
- Scan from 1028.950 -> 1028.930, stepsize 0.001 every 5 sec
- Scan from 1028.950 -> 1028.940 -> 1029.950, stepsize 0.001 every 5 sec
- Scan from 1028.950 -> 1028.940, stepsize 0.0005 "as fast as possible"
- constant wavelengths around 1028.940
- Scan to wavelengths < 1028.940 (heating) -> Jump to 1028.945 and fast scan back to 1028.940 (-> cooling)
The cooling effects of the laser can be observed well in the Schottky spectra :) |
79
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Sun May 16 07:18:56 2021 |
Night Shift Sebastian/Max/Noah | General | Preparation for automated laser scans |
We shut the laser system down to prepare automated laser scans |
Draft
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Fri May 14 09:35:20 2021 |
Nightshift | Runs | Coasting beam, scanning laser, ecooler on |
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Attachment 1: IMG-20210514-WA0018.jpg
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53
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Fri May 14 09:38:04 2021 |
Nightshift | Runs | Coasting beam, scanning laser, ecooler on |
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Attachment 1: IMG-20210514-WA0018.jpg
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54
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Fri May 14 09:38:43 2021 |
Nightshift | Runs | Coasting beam, ecooler on, scanning laser |
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Attachment 1: IMG-20210514-WA0019.jpg
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