 Sat Apr 2 05:08:00 2022, Kristian, General, Morning shift
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I see no updates in the log. Is the morning shift taking place?
For now I will stay at home and be on call. I can be at GSI in 20 min. Please let me know the status.
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Tue Apr 5 13:24:40 2022, Kristian, Detectors, PMT Cu
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| HV cable was in wrong channel in power supply. Now it is back to the correct position. Checked connection at the PMT. |
Tue Apr 5 13:28:06 2022, Kristian, DAQ, Spikes in PMT signal 
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| Occasionally, we noticed a spike in the PMT signal. No ions in the ring and at PMT Cu was not even supplied with HV. Has to be some electronic pickup |
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Tue Apr 5 14:51:51 2022, Kristian, DAQ, dark counts
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We shielded the PMTs, i.e., the N2 tube, which improved the Cu PMT background rate.
Without beam and ESR lights off:
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Fri Apr 8 11:16:57 2022, Kristian, Laser, Wavemeter
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We changed the fiber to the wavemeter. The third fiber worked best and we could operate the WM at low exposure times, i.e., below the laser repetition rate.
We used the neutral density filter to adapt the laser power that only one laser pulse is measured by the WM each time (Exposure time =34ms)
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Fri Apr 8 14:14:28 2022, Kristian, DAQ, Delay of bunch RF
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The bunch HF is now fed through a delay to shift the stop trigger relative to the PMT signal. The delay generator is placed directly after the CFG and before
splitting the signal for the two DAQs. The relative timing of both DAQs was not changed. |
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Sat Apr 9 06:42:23 2022, Kristian, Laser, Laser step size
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| We changed the laser step size to 0.002 nm which corresponds to 5.75 GHz. |
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Mon Apr 11 12:50:22 2022, Kristian, Accelerator, Th lifetime
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We used the counter to measure the lifetime. During the 30 min scan time dropped only slowly.
During a longer break, e.g., when the laser flash lamps are changed, one could take data over a longer time. |
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Mon Apr 11 22:14:51 2022, Konstantin, Sarper, Laser, Changing of the wavelength range
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| It is planned to change the scan range of the laser wavelength from 322.41 - 322.0 nm to 322.01 - 321.6 nm @ 4 a.m. |
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Thu Apr 7 19:13:26 2022, Konstantin, Patrick, Calibration, How to find the correct laser position
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In order to achieve the correct laser ion beam superposition one needs to do the following steps:
[LIST=1]
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Sun Apr 3 18:41:11 2022, Konstantin and Rodolfo, Laser, Beam Position Stabilization
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We (Konstantin and I) have optimized the TEM "laser-beam position stabilization".
- I took some pictures (screenshots) about the current setting*.
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Thu Mar 31 11:49:54 2022, Konstantin, Detectors, HV-Supply of particle detectors
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We cross-checked the cabeling of the particle detectors north and south. Particle detector south is connected to channel [B]HV5[/B] at the yellow "ESR Messplatz
III" patch-panel. Particle detector north is connected to channel [B]K5[/B] at the green "ESR Messplatz II" patch-panel. Red high voltage power-supply
is used to control the voltage. |
 Thu Mar 31 15:53:50 2022, Konstantin, Detectors, Control software for XUV and copper mirror detector
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> Attached you find a manual for the software used to control the movement of the XUV detector and the copper mirror detector.
> The software is also used to set the electrode voltages and coil currents of the XUV detector.
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Thu Mar 31 17:56:32 2022, Konstantin, DAQ, Photodiode test signal
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We used a signal generator to provide a 4MHz dummy-RF signal. This was divided by a factor of 2 for laser-"bunch" synchronization and by a factor of 200
for to provide the stop-tigger attached to the DAQ. With this Dummy-RF we were able to measure the relative arrival times of the laser at the photodiodes
located in the laser towers. Note that the signal of the southern photodiode arrives first. This is because the scale of the time axis is given in (10/3ns)-bins |
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Fri Apr 1 22:01:14 2022, Konstantin, Detectors, PMT operating voltages
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> During the testing of the PMTs the following operating voltages were applied:
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> PMT Cu: -1300V
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Sun Apr 3 18:52:30 2022, Konstantin, Calibration, Laser ion beam overlap
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We measured vertical and horizontal ion beam positions. Unfortunately, the horizontal scraper positions can not be manipulated
by the "Device Control" software. Robert Boywitt has supported us a lot to get the drives moving by using the expert software on
a local control PC, which can only be remotely accessed from beapc032 with the usual experiment account "atplaser". In the first
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Thu Apr 7 16:50:22 2022, Konstantin, Calibration, Spacial laser-ion overlap
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Laser-ion-beam overlap was achieved after measuring the ion beam positions (compare [URL=https://elog.gsi.de/esr/E142/83]Entry 83[/URL]).
Screenshots are comprised in the following table.
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Fri Apr 8 17:44:25 2022, Konstantin, Calibration, Final Timing
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We measured the timing for the laser bunch synchronization. A summary is given below.
[TABLE border="1"]
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Fri Apr 8 17:57:45 2022, Konstantin, DAQ, Laser scanning
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[TABLE border="1"]
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Tue Apr 12 17:01:30 2022, Konstantin, Detectors, Voltage PMT North
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| Voltage of PMT North has been increased from 2500 V to 2600 V. Additionally the threshold was adapted from 25 mV to 12 mV. |