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  Laser Cooling Experiment 2021, Page 3 of 5  Not logged in ELOG logo
Entry  Sun May 16 02:18:53 2021, Sebastian, General, UV Drop 
1:25 a.m. huge drop in UV laser power
-> small crystal bump with both y screws of bbo oven
Entry  Sun May 16 02:20:58 2021, Sebastian, General, "Der Laser ist (wieder) ok" 
 
Entry  Sun May 16 02:22:19 2021, Sebastian, General, "Der Laser ist ok" 
 
Entry  Fri May 14 09:35:20 2021, Nightshift, Runs, Coasting beam, scanning laser, ecooler on IMG-20210514-WA0018.jpg
 
Entry  Fri May 14 09:38:04 2021, Nightshift, Runs, Coasting beam, scanning laser, ecooler on IMG-20210514-WA0018.jpg
 
Entry  Fri May 14 09:38:43 2021, Nightshift, Runs, Coasting beam, ecooler on, scanning laser IMG-20210514-WA0019.jpg
 
Entry  Fri May 14 09:40:04 2021, Nightshift, Runs, Ecooling vs laser wavelength shift, coasting beam, laser stronger than Ecooling IMG-20210514-WA0017.jpg
Last three pictures where taken after 
first laser ion beam overlap adjustments

It seems to be that the interactions are 
better. We also see the laser earlier and 
stronger in the schottky 
Entry  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 :)
Entry  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
    Reply  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. 
Entry  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.
    Reply  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...
Entry  Wed May 12 09:05:48 2021, Keysight Settings, DAQ,  
 
Entry  Tue May 11 16:33:31 2021, Ken Ueberholz, Detectors, Detector control manual Manual.pdf
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.
Entry  Wed May 12 18:59:15 2021, Ken Ueberholz, General, Power is back 
Power is back and most things are running again
Entry  Wed May 12 22:28:55 2021, Ken Ueberholz, General, Bunching succesfull 
Bunching with 2 and 10 bunches succesfull
Entry  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 
Entry  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.
Entry  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
Entry  Thu May 13 23:42:37 2021, Ken Ueberholz, General, What was done Schottky1.jpegSchottky2.jpegSchottky3.jpegSchottky4.jpeg
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.
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