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 :)

Settings für Ekühler an und aus in SC4 und 
5

Tab "Kühler Elektronenstrahl"
An Gerät schicken

H=2
H=7
H=10
H=20
H=30

We performed several scans:
Close to the bucket middle
Over the bucket
Over the bucket, jumped to the "red side" 
of the bucket and captured and cooled the 
beam again.

Laser settings:
7 times revolution frequency and 740ps 
pulses - - > 3.4 +/- 1.2 GHz

Still to do:
Switch to 240ps pulses - - > 5.8GHz 
+/-1.3 GHz

Maybe:
Switch to 117ps pulses - - > 11.0 +/- 0.8 GHz
BUT here we have less laser power (max. 50 mW right after BBO crystal, so maybe only 30 mW at the laser-ion overlap)
available. Maybe we are lucky and it is 
enough to cool also the ion beam. :) 

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

https://tu-darmstadt.zoom.us/j/4948400422?pwd=SEJaUzBuYXM0TTd6UWxoZTFlWEZxUT09

Meeting ID: 494 840 0422
Passcode:  215586

We changed the horizontal position of the laser beam a bit, so that we maximized the fluorescence signal on the XUV detector (coasting beam, scanning laser (0.03 Hz)).

Old parameters: OffsetM Ax 0.00; Bx 0.00; Ay -0.08; By -0.40
New parameters: OffsetM Ax 0.00; Bx 0.35; Ay -0.08; By -0.40

Optimizing the laser bunch timing.
h = 7 (9.0389145 MHz)
Reprate is already set to same frequency.


Results: For h=7:
4 ns delay results in a maximum fluorescence rate in the XUV detector
25 ns delay shows the highest intensity in the Schottky spectrum while the laser operates at 1028.940 nm.

1:25 a.m. huge drop in UV laser power
-> small crystal bump with both y screws of bbo oven

Laser specs:
pulse length -> 482ps

~75mW UV Power inside ESR (depending on laser wavelength)

we see laser cooling with 482ps pulse length

pulse length -> 285ps

minimum 62mW inside ESR (depending on laser wavelength)

we also see laser cooling with 285ps pulse length

We saw some indications of laser cooling @ 166ps pulse length

We shut the laser system down to prepare automated laser scans

The automated laser scans are working now.
We can now scan with the following functions: triangle, sawtooth, cosinus/sinus, arctan, min (linear scan, than stands still)

We are now testing these scan functions with coasting beams; ecooler 10 mA.