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  Laser Cooling Experiment 2021, Page 2 of 5  Not logged in ELOG logo
Entry  Sat May 15 09:22:41 2021, Sebastian , Accelerator, Ekühler  IMG-20210515-WA0000.jpgB5FE1031-7FFD-44D3-92B0-75E0784718D9.jpeg
Settings für Ekühler an und aus in SC4 und 
5
Entry  Tue May 11 16:07:59 2021, Sebastian, DAQ, DAQ Manual DAQ_Manual.pdf
Attached you'll find a short manual for operating the whole DAQ system
Entry  Wed May 12 08:32:04 2021, Sebastian, Analysis, fluorescence & energetic overlap Screenshot_(154).png
During the night shift we saw several rises of the fluorescence (see another entry) and also energetic overlap in coasting beam modus.
Here the laser wavelength was stabilized @ 1028,967nm and electron cooler was switched off because of some fluctuations which we saw in the schottky.
Left part of the schottky picture shows the c3+ beam, the right part is the o4+ contamination.
Entry  Wed May 12 08:41:36 2021, Sebastian, Analysis, Laser stability 
During night shift the laser was very stable! Only minor fluctuations occured in the UV
Entry  Wed May 12 08:42:49 2021, Sebastian, Analysis, Laser scans / coastig beam / no ecooler Screenshot_(156).png
Attached you'll see a first laser scan of ~100GHz in the UV.
Entry  Wed May 12 09:04:48 2021, Sebastian, DAQ, Keysight AUtoCal IMG_20210510_143940_resized_20210512_090353546.jpg
 
Entry  Wed May 12 09:09:15 2021, Sebastian, DAQ, Fluorescence 1029967nm.png
fluorescence with detector in parking position
fixed laser wavelength
electron cooling ON, 
BUT we saw strange drifts in the Schottky spectra. It seems to be that these drifts come from the electron cooler! are the drift tubes grounded?

the drifts shift the ion beam over the transition which result in an increase of the XUV anode signal
Entry  Wed May 12 19:48:24 2021, Sebastian, General, DSG821 Network IMG_20210512_195329_resized_20210512_075346417.jpg
To implement the bunch Signal Generator (DSG821 inside ESR) you have to:

1. unplug the Ethernet cable
2. under System / io config set the ip address
3. set Sub mask
4. set DNS
5. very important: than press Apply!
6. plug in Ethernet cable
7. than a message like "successfully connected to network" should show up
8. you can crosscheck the Settings by pressing the "eye symbol"
Entry  Wed May 12 22:48:25 2021, Sebastian, General, DSG Control SCPI Commands 
Open Ultra Sigma
Press LAN
Press Search, after a while the whole rigol devices are shown. Press ok
Than you see the DSG821 (140.181.104.108) as online
right click -> open SCPI Command Terminal


*IDN?                 check for remote control
:FREQ 1.291MHz        set the RF Frequency to 1.291MHz
:FREQ?                return current frequency
:LEV 0.2V             set the amplitude to 200mV
:LEV?                 return current amplitude
:OUTP ON / OFF        set RF output ON or OFF
:OUTP?                returns 0 if output is OFF, returns 1 if output is ON

after some time there is an automatic logout of the scpi command panel. Close the panel and reopen the SCPI Command Terminal again to reconnect to DSG821 Signalgenerator. 
If this does not work, close the whole ultra sigma program, also in the taskbar (right click -> exit) and execute Ultra Sigma Program again
Entry  Wed May 12 22:57:41 2021, Sebastian, General, Laser Reprate 
laser reprate is seven times the revoolution frequency: 9.038283 MHz
pulse length: 735ps
Entry  Thu May 13 01:13:06 2021, Sebastian, General, Bunching frequencies 
relating to Danyals ID 25 post are the current bunching frequencies:

h=2      -->     2,5823668 MHz
h=4      -->     5,1647336 MHz
h=6      -->     7,7471004 MHz
h=7      -->     9,0382838 MHz
h=8      -->     10,3294672 MHz
h=10     -->     12,911834 MHz
h=12     -->     15,4942008 MHz
h=14     -->     18,0765676 MHz
h=16     -->     20,6589344 MHz
h=18     -->     23,2413012 MHz
h=20     -->     25,823668 MHz
h=30     -->     38,735502 MHz
Entry  Thu May 13 01:21:30 2021, Sebastian, General, Current schedule ... so far 
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  Thu May 13 01:55:15 2021, Sebastian, General, ESR amplifier reset / laser check IMG_20210513_014345_resized_20210513_015540959.jpgIMG_20210513_014353_resized_20210513_015541291.jpg
we had to go into the ESR because the amplifiers hooked up. both amplifiers were resetted!

we also checked why we didnt see the laser at the exit window.
Laser Shutter @ the exit is closed......................... E02VVLF2t needs to be opened!
Entry  Thu May 13 02:42:58 2021, Sebastian, General, Lasershutter ESR Entrance?! IMG_20210513_020027_resized_20210513_024049198.jpg
attached should be the name of the entrance laser shutter. just in case somebody will close it ;)
Entry  Thu May 13 02:45:29 2021, Sebastian, Analysis, ESR pressure 8x
 
Entry  Fri May 14 01:28:04 2021, Sebastian, General, "new" laser wavelength 
Minor changes in electron cooler voltage (~+13V, now 66903V measured by DMM) leads to that we had to shift the laser wavelength to:

1028,965nm 

to see an increase of the countrate of the XUV ANODE Signal.

electron cooler ON
electron cooler current (SET 120mA, HKR "measured" 102mA)
bunched beam, h=20
Entry  Fri May 14 08:55:53 2021, Sebastian, General, ToDO 14.5 ...so far 
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
Entry  Fri May 14 09:00:55 2021, Sebastian, General, UNILAC Problems 
~30 min downtime

--> LASER ADJUSTEMENTS!
Entry  Fri May 14 21:43:40 2021, Sebastian, General, "problems accelerator" 
There are cooling problems of some accelerator devices
short break, hopefully :)
Laser is switched of for some rest
Entry  Sat May 15 09:23:52 2021, Sebastian, Accelerator, Ekühler 
Tab "Kühler Elektronenstrahl"
An Gerät schicken
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