To reduce the load on the VUPROM TDC, we unplugged the TDC inputs for the front and back signals of the MCP of the XUV detector.
The Anode signal is still plugged in and should be sufficient for the analysis.

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

~30 min downtime

--> LASER ADJUSTEMENTS!

1.) ion lasser overlap and scraper test

2.) change bunching frequency to middle of ecooled coasting beam

3.) long time measurements see labbook HKR
3.1) try ecooler on/off ; bunch on / off ; laser fixed on / off ; laser scanning on / off ; try different bunching amplitudes (MAX :LEV 0.25V) ; try other h = 10, 7, etc...
3.2) Dont forget to plug in the schottky trigger -> maybe change acquisition and analysis time if needed

4.) XUV detector tests
4.1.) laser - bunch timing by checking xuv anode signal

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 

Telephone numbers:

ESR laser lab: +49 (0)6159 71 - 2882
ESR measurement hut: +49 (0)6159 71 - 2880
HKR (main control room): +49 (0)6159 71 - 2317 or 2245

here is the zoom information:

https://tu-darmstadt.zoom.us/j/2183997317?pwd=WGc2TEkxYlEyNFhMWm02bFhqRnRVUT09

Meeting-ID: 218 399 7317
Passwort: 481607

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

pulse length -> 285ps

minimum 62mW inside ESR (depending on laser wavelength)

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...

Right now, we have to adjust the ion beam a bit to overlap better with the laser beam.
We keep the laser wavelength at resonance with the ions and try to optimize the fluorescence signal on the XUV detector while moving the ion beam.

laser is 4-6mm below the ion beam.
It could be that the interaction between both beams came only from the interaction between the laser halo with the ion beam ?!

We shut the laser system down to prepare automated laser scans

Power is back and most things are running again

The lasersystem now operates at a reparte of 9.038946 MHz. This is 7 times f_rev (see previous post).

In the future, the laser-bunch-timing can be adjusted.

The ions were changed to a different speed today at 2 PM. The new revolution frequency is now 1.291278 MHz.

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

Meeting ID: 494 840 0422
Passcode:  215586

attached should be the name of the entrance laser shutter. just in case somebody will close it ;)

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.