HOME ESR EXPERIMENTS LABS etc
E121 E127 E132 E125 E143 laser_cooling_2021 E142 Ê128 E146 E0052 E0018 E0028 E0038
  Laser Cooling Experiment 2021, Page 2 of 5  Not logged in ELOG logo
ID Date Authordown Category Subject
  63   Sat May 15 09:22:41 2021 Sebastian AcceleratorEkühler
Settings für Ekühler an und aus in SC4 und 
5
  3   Tue May 11 16:07:59 2021 SebastianDAQDAQ Manual
Attached you'll find a short manual for operating the whole DAQ system
  11   Wed May 12 08:32:04 2021 SebastianAnalysisfluorescence & energetic overlap
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.
  12   Wed May 12 08:41:36 2021 SebastianAnalysisLaser stability
During night shift the laser was very stable! Only minor fluctuations occured in the UV
  13   Wed May 12 08:42:49 2021 SebastianAnalysisLaser scans / coastig beam / no ecooler
Attached you'll see a first laser scan of ~100GHz in the UV.
  14   Wed May 12 09:04:48 2021 SebastianDAQKeysight AUtoCal
  16   Wed May 12 09:09:15 2021 SebastianDAQFluorescence
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
  23   Wed May 12 19:48:24 2021 SebastianGeneralDSG821 Network
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"
  26   Wed May 12 22:48:25 2021 SebastianGeneralDSG 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
  27   Wed May 12 22:57:41 2021 SebastianGeneralLaser Reprate
laser reprate is seven times the revoolution frequency: 9.038283 MHz
pulse length: 735ps
  33   Thu May 13 01:13:06 2021 SebastianGeneralBunching 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
  34   Thu May 13 01:21:30 2021 SebastianGeneralCurrent 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...
  35   Thu May 13 01:55:15 2021 SebastianGeneralESR amplifier reset / laser check
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!
  36   Thu May 13 02:42:58 2021 SebastianGeneralLasershutter ESR Entrance?!
attached should be the name of the entrance laser shutter. just in case somebody will close it ;)
  37   Thu May 13 02:45:29 2021 SebastianAnalysisESR pressure
  43   Fri May 14 01:28:04 2021 SebastianGeneral"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
  50   Fri May 14 08:55:53 2021 SebastianGeneralToDO 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
  51   Fri May 14 09:00:55 2021 SebastianGeneralUNILAC Problems
~30 min downtime

--> LASER ADJUSTEMENTS!
  58   Fri May 14 21:43:40 2021 SebastianGeneral"problems accelerator"
There are cooling problems of some accelerator devices
short break, hopefully :)
Laser is switched of for some rest
  64   Sat May 15 09:23:52 2021 SebastianAcceleratorEkühler
Tab "Kühler Elektronenstrahl"
An Gerät schicken
ELOG V3.1.5-fc6679b