 Fri Jun 20 15:58:21 2025, Wilfried, Konstantin, Simon, Laser, Laser stepwidth
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From previous Bi-Beamtimes, we expect the width of the transition to be >50GHz (FWHM). The current step width is 0.002nm which corresponds to 8GHz, so the
laser would be in resonance for 6 steps.
We should aim for at least 5 steps in resonance.
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Sat Jun 21 00:23:22 2025, Rodolfo, Laser, Dye 
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| I have prepared new (fresh) dye solutions of Fluorescein 27: 2 charges. They are in the Safety Cabinet (Sicherheitsschrank) in the ESR Laser lab |
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Sat Jun 21 02:32:24 2025, Alex, Anton, Rodolfo, Hiroshi, Carsten, Laser, Laser scanning setting
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This is the initial scanning range
[LIST]
[*] 3 Loops
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Sat Jun 21 03:06:19 2025, Rodolfo, Alex, Hiroshi, Anton, Laser, beam overlap with t-scrapers
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[TABLE border="1"]
motor|ion beam position (mm) from outside|ion beam position (mm) from inside
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Sat Jun 21 07:28:35 2025, Arya, Julien, Wilfried, Laser, Laser Timing
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We roughly adjusted the timing based on attachment 1, for ions to be in center of electron cooler (east arc), corrected for PMTs being 2.5m closer to the
north on the west arc
then did a new 30 injection accumulation (10.8k counts on particle detector) and readjusted the timing to fine tune this
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Mon Jun 23 10:52:34 2025, Julian, Lukas, Zsolt, Nadine, Konstantin, Laser, Frequency conversion unit
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We exchanged the old BBO of the Cobra's FCU with a new one. The output power of the Cobra was around 120mJ. In the end, we achieved a UV power of about
21mJ. In addition, we optimized the fiber-coupling to the wavemeter. |
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Wed Jun 25 05:53:54 2025, Rodolfo, Laser, FCU
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| Cobra's FCU was recalibrated. Table saved as FCU_547-554_RS_2024-06-25.fcu. |
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Fri Jun 27 06:55:45 2025, Esther. Konstantin, Laser, Laser-ion overlap
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We cross-checked the laser-ion superposition by using the T-scrapers. We did it only after the scans in order to do not change the duty cycle by much. Attachements
are in the order of the measurements compiled in the table.
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Sat Jun 21 11:42:50 2025, Arya, Julien, Wilfried, General, Test laser scan
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Test scan to see whether laser spot is moving while scanning
Aborted accumulation because SIS stopped. 12.9k counts
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Sun Jun 22 11:31:59 2025, Arya, Carsten, Julien, Konstantin, General, Summary morning shift
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1. UNILAC running again, so we resumed the beam tuning wherre we stopped yesterday at 14:00
2. Goals: Reduce intensity and lifetime of "antibunch" contamination while maximising intensity for main bunch/on PD
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Tue May 20 16:14:30 2025, Rodolfo, Simon, Detectors, PMT arrangement at ESR
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This is the arrangement of the photomultipiers at the optical detection region at ESR for Thorium 2025
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Mon Jun 2 16:36:57 2025, Carsten, Detectors, Mesycontrol
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ssh -Y litv-exp@x86l-204
'mesycontrol' |
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Wed Jun 4 16:17:47 2025, Simon, Detectors, Nitrogen
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| The nitrogen supply for the PMTs is turned [B]ON[/B]. |
 Wed Jun 4 16:18:57 2025, Rodolfo, Simon, Detectors, PMT dark count rates
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I adjusted the offsets of the amplifiers in the cave and measured the dark count rates :
[TABLE border="1"]
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Wed Jun 11 16:44:39 2025, Carsten, Jan, Detectors, Detector voltages and thresholds for DAQ2 (Mesycontrol)
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Voltages (2650v) for the small band 9423 is ok. Signals are nicely separated from background, thresholds can be easily set.
For the broadband 9422 the voltage is by far too low. Signals and BG are barely separated.
Increased voltage from 1500V to 1750V (according to datasheet Vmax = 2500V, 1500 V is the min voltage for gain 1e6...).
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Mon Jun 16 21:47:23 2025, Carsten, Wilfried, Simon , Detectors, New threshold values for PMTs
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We adjusted the thresholds for the PMTs and increased the voltage of PMT middle to 2.7kV
[TABLE border="1"]
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Sat Jun 21 03:13:02 2025, Alex, Anton, Rodolfo, Hiroshi, Detectors, Part Det South
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Bunch signal on Particle Detector South. On the
[LIST]
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Sat Jun 21 17:00:10 2025, Carsten, Peter, Danyal, Kristian, Marek, Detectors, PMT north exchanged
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We noted that the dark countrate of PMT north is about 20x higher than that of PMT middle.
We went into the ESR cave to look for stray light.
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Sat Jun 21 18:00:49 2025, Carsten, Peter, Danyal, Kristian, Marek , Detectors, PMT signals
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Carsten and Kristian changed (18:00) the thresholds of PMT north and PMT middle in the ESR cave.
See picture below. The effect is negligible.
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Sat Jun 21 21:55:18 2025, Peter, Danyal, Marek, Detectors, PMT rates
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We have made two foam rings (outer diameter ca. 70 mm with a thickness of 10 mm each and placed them successively underneath PMT north.
ring 1: ID = 55 mm
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