HOME ESR EXPERIMENTS LABS etc
E121 E127 E132 E125 E143 laser_cooling_2021 E142 Ê128 E146 E0052 E0018 E0028 E0038 E0075 E0203_E0018 E0052_2025
  Nuclear hyperfine mixing in 229Th89+ 2025, Page 1 of 4  Not logged in ELOG logo
Entry  Sat Jun 28 06:29:58 2025, Stefan, Simon, Runs, Morning shift 28.06. 
6:30 Problem with ion source, on-call service is called
7:30 There is a short in the ion source and it needs to be changed. Expected down time about 2h
10:30 Ion source was successfully changed, but while ramping up the source a power supply failed. Next on-call service is on their way to GSI.

Time Part. Det. Int SIS-intensity accumulations in ESR cooler-HV PTB K250 cooler-HV PTB red cooler-HV orange LMD-DAQ1 Files LMD-DAQ2 Files scan range(nm) number of positions dwell time (laser shots) n loops checked laser position mesytec rate ok comments
22:08 17000 2.5e9 30 104524 104527 104528 205 233 551.91 - 549.41 501 15 1 yes yes -
Entry  Fri Jun 27 22:14:35 2025, Anton, Finn, Carsten, Runs, Runs night shift 27.06. 28.06 
22:10 SIS Trafo GS09DT scale was changed to 4e8 (not just the lassie monitor)
23:50 Ausfall ESR: GE01 KP01 bis KP05 und KP22 bis KP24; Korrekturelement: GE02KX6 und GE01KX2; beam loss during measurement
01:45 reser press air Scrapers: GE02DD2_G (sc8,11); GE02DS03HG(sc7,8,11); GE01DD2IG(was sc7,10,11)(now7,8,11)
Time Part. Det. Int SIS-intensity accumulations in ESR cooler-HV PTB K250 cooler-HV PTB red cooler-HV orange LMD-DAQ1 Files LMD-DAQ2 Files scan range(nm) number of positions dwell time (laser shots) n loops checked laser position mesytec rate ok comments
22:08 17000 2.5e9 30 104524 104527 104528 205 233 551.91 - 549.41 501 15 1 yes yes TE slits -6 +6
22:27 7200 4e8 30 104524 104527 104528 206 234 551.91 - 549.41 501 15 1 yes yes TE slits -6 +6 ! small peak on right side, not good scraped
23:19 6000 2.5e9 30 104524 104527 104528 207 235 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7
23:35 15000 2.3e9 30 104524 104527 104528 208 236 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7
23:47 00 2.3e9 30 104524 104527 104528 209 237 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \ scan not compete, beam loss during measurement
00:17 6200 2.7e9 30 104524 104527 104528 210 238 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7
00:45 6400 2.6e9 30 104524 104527 104528 211 239 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \small peak on right side, badly scraped
01:00 5100 2.75e9 30 104524 104527 104528 212 240 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \small peak on right side, badly scraped
01:15 5200 2.6e9 30 104524 104527 104528 213 241 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \small peak on right side, badly scraped
01:45 4900 2.3e9 30 104524 104527 104528 214 242 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \bigger peak on right side, badly scraped
01:58 12600 2.25e9 30 104524 104527 104528 215 243 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \small peak on right side, badly scraped
02:13 12000 2.4e9 30 104524 104527 104528 216 244 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \small peak on right side, badly scraped
02:28 13900 2.45e9 30 104524 104527 104528 217 245 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \small peak on right side, badly scraped
02:48 17000 2.45e9 30 104524 104527 104528 218 246 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7
02:58 13500 2.45e9 30 104524 104527 104528 219 247 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7
03:13 14900 2.5e9 30 104524 104527 104528 220 248 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \badly scraped
03:27 5200 2.5e9 30 104524 104527 104528 221 249 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \badly scraped
03:42 13000 2.5e9 30 104524 104527 104528 222 250 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \badly scraped
04:08 14300 2.9e9 30 104524 104527 104528 223 251 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7
04:23 15400 2.9e9 30 104524 104527 104528 224 252 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7
04:38 13800 2.9e9 30 104524 104527 104528 225 253 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \badly scraped
05:03 12800 2.5e9 30 104524 104527 104528 226 254 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \badly scraped
05:23 3900 2.6e9 30 104524 104527 104528 227 255 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \badly scraped
05:38 11200 3.e9 30 104524 104527 104528 228 256 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7
05:53 3900 2.5e9 30 104524 104527 104528 229 257 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \badly scraped
06:08 11700 low.intensity 30 104524 104527 104528 230 258 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7 \badly scraped

During whole night shift scraping right peak did not work consistently. Remaining intensity varied from similar peak height compared to torium down to about 20%.
Entry  Fri Jun 27 14:23:39 2025, Nils, Wilfried, Carsten, Julian, Runs, Runs afternoon shift 27.06. 
15:30 We have a break due to an issue at UNILAC (quadrupole failed). Also radiation safety interlock was triggered at the fragment separator. This also pushed a faradaycup into the ESR (GE01DC3VP).
Just before the issue during the last bunching, the peak was misaligned to the marker in the Schottky. The marker was sitting on the right flank. So the electron-cooled 229Th did not match with the bunching frequency anymore. We are preparing to adjust the cooler voltage to fix this. For some reason the frequency recovered and is back to its original position. However, our accumulations do not seem to work as well as before, we stagnate much earlier and at a much lower level.

15:50 Beam is back, Carsten is still investigating the drop in intensity we saw before the UNILAC failure.

17:15 TE slits were on -8 and +8, opening to -11 and +11, no change to acquisition pattern, something is still wrong

18:00 We were locked out by HHT people for 30+ mins

18:27 We had to call in ESR support

Time Part. Det. Int SIS-intensity accumulations in ESR cooler-HV PTB K250 cooler-HV PTB red cooler-HV orange LMD-DAQ1 Files LMD-DAQ2 Files scan range(nm) number of positions dwell time (laser shots) n loops checked laser position mesytec rate ok comments
14:24 15800 2.74 e9 30 104524 104527 104528 196 224 551.91 - 549.41 501 15 1 yes yes Carsten optimizing beam at HKR with ESR colleagues
14:24 6800 1.16 e9 30 104524 104527 104528 197 225 551.91 - 549.41 501 15 1 yes yes Carsten is back in measurement hut
16:30 1100 1.1 e9 40 104524 104527 104528 198 226 551.91 - 549.41 501 15 1 yes yes Searching for reason for small particle number
17:00 1200 0.5 e9 30 104524 104527 104528 199 227 551.91 - 549.41 501 15 1 yes yes
19:57 7800 1e9 30 104524 104527 104528 200 228 551.91 - 549.41 501 15 1 yes yes Restarting some things at ESR
20:16 6800 1.5e9 30 104524 104527 104528 201 229 551.91 - 549.41 501 15 1 yes yes Restarting some things at ESR
20:41 7200 1.5e9 30 104524 104527 104528 202 230 551.91 - 549.41 501 15 1 yes yes Restarting some things at ESR
21:28 6000 2.65e9 30 104524 104527 104528 203 231 551.91 - 549.41 501 15 1 yes yes
21:47 6600 2.7e9 30 104524 104527 104528 204 232 551.91 - 549.41 501 15 1 yes yes
22:08 17000 2.5e9 30 104524 104527 104528 205 233 551.91 - 549.41 501 15 1 yes yes TE slits -7 +7
Entry  Fri Jun 27 11:21:25 2025, Esther, Konstantin, DAQ, Timing 
We cross-checked the timing. Laser pulse is detected at bins 136 (PD-North) and 171 (PD-south), respectively. Therefore, the laser puls is in the electron cooler at 153.5. The revolution period corresponds to 3e8Hz / 1.54315MHz = 194. 
The ion bunch must travel 2.5m more than the half of the circumference (108.3m). Taking this into account, the ion bunch must be detected (0.5 + 2.5 / 108.3) * 194 = 101.5 bins later (meaning less) than 153.5.
Finally, we are happy that the timing is still perfect, since the ion bunch arrives at 52. 
Entry  Fri Jun 27 06:55:45 2025, Esther. Konstantin, Laser, Laser-ion overlap 2025-06-27_06-52-01-807.png2025-06-27_07-12-27-135.png2025-06-27_07-32-28-599.png2025-06-27_07-51-52-620.png
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.

motorion beam position (mm) from inside
GECEDS1VU -0,5
GECEDS1HA -4
GECEDS2VU 0.9
GECEDS2VU 0


Still looks fine to us.
Entry  Fri Jun 27 06:13:02 2025, Esther, Konstantin, Runs, Early shift - data taking 
Notes:
1. TE slits at -10 and +10
2. SIS intensity unstable until about 9:00 after that it became much more stable
3. brief interruption between 09:30 and 10:03 due to interlock issue at SIS

Time Part. Det. Int SIS-intensity accumulations in ESR cooler-HV PTB K250 cooler-HV PTB red cooler-HV orange LMD-DAQ1 Files LMD-DAQ2 Files scan range(nm) number of positions dwell time (laser shots) n loops checked laser position mesytec rate ok comments
06:15 16300 1.5-3.5 e9 30 104522 104526 104526 172 199 551.91 - 549.41 501 15 1 yes yes
06:30 13500 1.5-3.5 e9 30 104522 104526 104526 173 200 551.91 - 549.41 501 15 1 yes yes
06:44 4000 1.5-2 e9 30 104522 104526 104526 174 201 551.91 - 549.41 501 15 1 yes yes beam scraped vertically with scraper 1 after end of laser scan (see entry 66), scraper left in but tilted to allow for injection
07:05 14800 2-3.5 e9 30 104522 104526 104526 175 202 551.91 - 549.41 501 15 1 yes yes beam scraped horizontally with scraper 1 after end of laser scan (see entry 66), scraper 1 moved back out
07:25 14000 1.1-2.6 e9 30 104522 104526 104526 176 203 551.91 - 549.41 501 15 1 yes yes beam scraped horizontally with scraper 2 after end of laser scan (see entry 66), scraper 2 left in but tilted to allow for injection
07:44 4200 1-2.5 e9 30 104522 104526 104526 177 204 551.91 - 549.41 501 15 1 yes yes beam scraped horizontally with scraper 2 after end of laser scan (see entry 66), scraper 2 moved back out
08:12 5700 1-2.5 e9 30 104522 104526 104526 178 205 551.91 - 549.41 501 15 1 yes yes !!file in DAQ1 not closed after end of scan!!; ~5 injections missing because nothing came from SIS
08:27 16000 1.5-3 e9 30 104522 104526 104526 178 206 551.91 - 549.41 501 15 1 yes yes !!file in DAQ1 still open from last scan!!
08:44 11700 1.5-3 e9 30 104522 104526 104526 179 207 551.91 - 549.41 501 15 1 yes yes
09:00 15600 2.6-3 e9 30 104522 104526 104526 180 208 551.91 - 549.41 501 15 1 yes yes
09:24 6500 2.8 e9 30 104522 104526 104526 181 209 551.91 - 549.41 501 15 1 yes yes
10:13 14600 2.2 e9 30 104522 104526 104526 182 210 551.91 - 549.41 501 15 1 yes yes
10:31 183 211 BAD FILES: ESR not stopped in SC9, injection during laser scan
10:39 14500 2.6 e9 30 104522 104526 104526 184 212 551.91 - 549.41 501 15 1 yes yes
10:55 15400 2.3 e9 30 104522 104526 104526 185 213 551.91 - 549.41 501 15 1 yes yes
11:11 15500 2.6 e9 30 104522 104526 104526 186 214 551.91 - 549.41 501 15 1 yes yes
11:27 15800 2.5 e9 30 104522 104526 104526 187 215 551.91 - 549.41 501 15 1 yes yes
11:41 5200 1.4-2.6 e9 30 104522 104526 104526 188 216 551.91 - 549.41 501 15 1 yes yes
11:56 16500 2.6 e9 30 104522 104526 104526 189 217 551.91 - 549.41 501 15 1 yes yes
12:12 15000 2.9 e9 30 104522 104526 104526 190 218 551.91 - 549.41 501 15 1 yes yes
12:27 15000 2.8 e9 30 104522 104526 104526 191 219 551.91 - 549.41 501 15 1 yes yes
12:44 15800 2.9 e9 30 104522 104526 104526 192 220 551.91 - 549.41 501 15 1 yes yes
13:21 5400 2.3 e9 30 104522 104526 104526 193 221 551.91 - 549.41 501 15 1 yes yes
13:42 4800 2.6 e9 30 104522 104526 104526 194 222 551.91 - 549.41 501 15 1 yes yes
13:59 6200 2.6 e9 30 104522 104526 104526 195 223 551.91 - 549.41 501 15 1 yes yes
Entry  Thu Jun 26 22:51:04 2025, Hendrik, Finn, Runs, Nightshift data runs 
After the scan at 22:04 teh FCU new was new calibrated. For this MEdusa was stopped and reopened in the laser lab. This stops the Labview server, and as a consequence the the connection to the MBS was lsot. Then, MBS needs to be restarted and the online data is cleared. Such an intervention should avoided as good as possible.
A pratical solution for beamtimes with such long data taking is still pending.
When trying to restart MBS MBS completlz hung up also resl etc did not work. Crate powered down and restarted.

23:10 Quadrupole magnet stopped working, lost beam in ESR. Contacted on-call ESR service

Time Part. Det. Int SIS-intensity accumulations in ESR cooler-HV PTB K250 cooler-HV PTB red cooler-HV orange LMD-DAQ1 Files LMD-DAQ2 Files scan range(nm) number of positions dwell time (laser shots) n loops checked laser position mesytec rate ok comments
0:15 8000 1.5-3.5 e9 30 104522 104526 104526 150 177 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
0:28 20900 1.5-3.5 e9 30 104522 104526 104526 151 178 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
0:59 19000 2.3-2.7 e9 30 104522 104526 104526 152 179 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
1:14 14500 1.5-3.5 e9 30 104522 104526 104526 153 180 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
1:30 19800 1.5-3.5 e9 30 104522 104526 104526 154 181 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
1:45 18000 1.5-3.5 e9 30 104522 104526 104526 155 182 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
2:01 6600 1.5-3.5 e9 30 104522 104526 104526 156 183 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
2:18 14500 1.5-3.5 e9 30 104522 104526 104526 157 184 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
2:36 14700 1.5-3.5 e9 30 104522 104526 104526 158 185 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
2:45 6000 1.5-3.5 e9 30 104522 104526 104526 159 186 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
3:00 5500 1.5-3.5 e9 30 104522 104526 104526 160 187 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
3:17 5200 1.5-3.5 e9 30 104522 104526 104526 161 188 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
3:34 14300 1.5-3.5 e9 30 104522 104526 104526 162 189 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
3:50 17200 1.5-3.5 e9 30 104522 104526 104526 163 190 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
4:07 5000 1.5-3.5 e9 30 104522 104526 104526 164 191 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
4:22 16500 1.5-3.5 e9 30 104522 104526 104526 165 192 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
4:39 14000 1.5-3.5 e9 30 104522 104526 104526 166 193 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
4:55 17000 1.5-3.5 e9 30 104522 104526 104526 167 194 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
5:12 16500 1.5-3.5 e9 30 104522 104526 104526 168 195 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
5:26 14000 1.5-3.5 e9 30 104522 104526 104526 169 196 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
5:43 13100 1.5-3.5 e9 30 104522 104526 104526 170 197 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
5:56 16500 1.5-3.5 e9 30 104522 104526 104526 171 198 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
Entry  Thu Jun 26 21:27:34 2025, Carsten, Jan, Simon, Calibration, Timing Bildschirmfoto_timing_new_2025-06-26_19-00-04.png
We checked the timing (before the start of the measurement cycle documented below).
Timing and measurement window are attached.
Entry  Thu Jun 26 19:01:46 2025, Carsten, Jan, Simon, Runs, Late shift 26.06. 

Scan parameters:
scan range551.91 - 549.41
positions501
step width0.005nm
advance after15 rising edges
iterations1
rev. frequency 1.54315e6




Time Part. Det. Int SIS-intensity accumulations in ESR cooler-HV PTB K250 cooler-HV PTB red cooler-HV orange LMD-DAQ1 Files LMD-DAQ2 Files scan range(nm) number of positions dwell time (laser shots) n loops checked laser position mesytec rate ok comments
19:15 23000 1.5-3.5 e9 33 104522 104526 104526 142 170 551.91 - 549.41 501 15 1 yes yes TE slits at -10 and +10, SIS intensity unstable
19:41 19000 3.3e9 30 104522 104526 104526 143 171 551.91 - 549.41 501 15 1 yes yes TE slits at -7 and +7
20:08 17500 3.3e9 25 104522 104526 104526 144 172 551.91 - 549.41 501 15 1 yes yes -
20:24 7000 3.3e9 25 104522 104526 104526 145 173 551.91 - 549.41 501 15 1 yes yes low Part. Det. Int maybe due to wrond position of part. det.
21:19 7000 3.5e9 25 104522 104526 104526 146 174 551.91 - 549.41 501 15 1 yes yes TE slits at -8 and +8
21:40 14000 3.3e9 25 104522 104526 104526 147 175 551.91 - 549.41 501 15 1 yes yes adjusted particle detector position
22:04 19500 3.3e9 40 104522 104526 104526 148 176 551.91 - 549.41 501 15 1 yes yes


After the scan at 22:04 teh FCU new was new calibrated. For this MEdusa was stopped and reopened in the laser lab. This stops the Labview server, and as a consequence the the connection to the MBS was lsot. Then, MBS needs to be restarted and the online data is cleared. Such an intervention should avoided as good as possible.
A pratical solution for beamtimes with such long data taking is still pending.
When trying to restart MBS MBS completlz hung up also resl etc did not work. Crate powered down and restarted.
Entry  Thu Jun 26 18:13:17 2025, Jan, Carsten, Detectors, PMT voltages & thresholds 
current settings of PMT voltages and thresholds at the CAEN CFD:

PMT South   [HV ch2: 2700V]  [CFD ch0: 8]

PMT Middle  [HV ch1: 2850V]  [CFD ch1: 8]

PMT Nord    [HV ch3: 2850V]  [CFD ch2: 9]
Entry  Wed Jun 25 05:53:54 2025, Rodolfo, Laser, FCU 
Cobra's FCU was recalibrated. Table saved as FCU_547-554_RS_2024-06-25.fcu.
Entry  Tue Jun 24 22:24:36 2025, Carsten, Finn, Hiroshi, Esther, Rodolfo, Runs, Data taking (night shift 24.06.) 

Scan parameters:
scan range551.91 - 549.41
positions501
step width0.005nm
advance after15 rising edges
iterations1
rev. frequency 1.54315e6


Notes:
1. NTCAP was only started after the fourth scan. The file timestamp is '2025-06-25_00-02-08'.
2. Beam was lost at 03:45 and could not be recovered by the operators. On-call service was called but they have to replace a part, current estimate is 2-3 hours.

Time Part. Det. Int SIS-intensity accumulations in ESR cooler-HV PTB K250 cooler-HV PTB red cooler-HV orange LMD-DAQ1 Files LMD-DAQ2 Files scan range(nm) number of positions dwell time (laser shots) n loops checked laser position comments
22:39 13500 2.4e9 60 104510 104514 104514 128 157 551.91 - 549.41 501 15 1 yes 60 injections, cooling time (SC 7) 28s -> 32s
23:00 11500 2.4e9 45 104510 104514 104514 129 158 551.91 - 549.41 501 15 1 yes 45 injections
23:20 10500 2.4e9 45 104510 104514 104514 130 159 551.91 - 549.41 501 15 1 yes
23:44 9100 2.4e9 45 104510 104514 104514 131 160 551.91 - 549.41 501 15 1 yes
00:05 14000 2.4e9 60 104510 104514 104514 132 161 551.91 - 549.41 501 15 1 yes back to 60 injections
00:28 14300 2.4e9 75 104510 104514 104514 133 162 551.91 - 549.41 501 15 1 yes 75 injections, mesytec channel threshold 0-3 set 255
01:26 13200 2.4e9 75 104510 104514 104514 134 163 551.91 - 549.41 501 15 1 yes there was an interruption at the source, took some time to get the beam back
01:48 10500 2.3e9 75 104510 104514 104514 135 164 551.91 - 549.41 501 15 1 yes
02:10 12400 2.3e9 75 104510 104514 104514 136 165 551.91 - 549.41 501 15 1 yes
02:33 9600 2.4e9 75 104510 104514 104514 137 166 551.91 - 549.41 501 15 1 yes
02:55 10000 2.4e9 75 104510 104514 104514 138 167 551.91 - 549.41 501 15 1 yes
03:18 9600 2.4e9 75 104510 104514 104514 139 168 551.91 - 549.41 501 15 1 yes
Entry  Tue Jun 24 18:49:18 2025, Carsten, Rima, Nils, Simon, Runs, Second attempt (Late shift 24.06.) 

Scan parameters:
scan range551.91 - 549.41
positions501
step width0.005nm
advance after15 rising edges
iterations1
rev. frequency 1.54315e6



Time Part. Det. Int SIS-intensity accumulations in ESR cooler-HV PTB K250 cooler-HV PTB red cooler-HV orange LMD-DAQ1 Files LMD-DAQ2 Files scan range(nm) number of positions dwell time (laser shots) n loops checked laser position comments
19:03 14800 2.7e9 60 104510 104514 104514 118 147 551.91 - 549.41 501 15 1 yes TE beamline slits -30 +30
19:22 14900 2.7e9 60 104510 104514 104514 119 148 551.91 - 549.41 501 15 1 yes -
19:40 14500 2.7e9 60 104510 104514 104514 120 149 551.91 - 549.41 501 15 1 yes TE beamline slits -20 +20
19:58 13800 2.0e9 60 104510 104514 104514 121 150 551.91 - 549.41 501 15 1 yes -
20:18 10800 2.1e9 60 104510 104514 104514 122 151 551.91 - 549.41 501 15 1 yes -
20:37 10100 2.1e9 60 104510 104514 104514 123 152 551.91 - 549.41 501 15 1 yes -
20:56 10500 2.1e9 60 104510 104514 104514 124 153 551.91 - 549.41 501 15 1 yes -
21:15 9000 2.2e9 60 104510 104514 104514 125 154 551.91 - 549.41 501 15 1 yes after this we change to 45 injections to give more cave access to HHT
21:37 11500 2.3e9 45 104510 104514 104514 126 155 551.91 - 549.41 501 15 1 yes small pause for HHT
22:13 13400 2.5e9 45 104510 104514 104514 127 156 551.91 - 549.41 501 15 1 yes small pause for HHT, cooling time in SC7 increased from 20s to 28 s
Entry  Tue Jun 24 12:25:34 2025, Carsten, Detectors, PMT behaviour - noise / PMT voltages / CFD Threshholds / CAEN Power supply (broken channel resetted) 
In position North there is still the "old" 9423B PMT that draws quite some current.
On this detector threre is also some quite substantial noise. Very likely the base is not ok any more. Noise was much lesss for the other two PMTs.
Since position NORTH is the position with the largest sold angle, if there is another break from the accelerator we should exchange it against SOUTH.
It was also difficult to ramp up PMT north ; and I thought that againa channel broke (showing UnV not OVC (Overcurrent)). However, the PS is resetted if
you switch of the whole crate (aka switch the PS off). Before doing so, please ramp down the other channels slowly as intended.


Please leave the PMTs (besides you go in to exhchange the PMTs).
If you ramp pt PMT North (or the same detector at a different position), start with 2400 V and then slowly increase by steps of 50V.

Checked theresholds (but during injections, so in presence of electronic noise from injection). A further adjusted might be done later when we have measurement conditions.
(Or if we have time to exchange the PMTs).


Presently we have the following settings for CAEN:


CH1: Middle 2750 V, Thr 9
CH2: South 2700 V, Thr 7
CH3: North 2800 V, Thr 9
    Reply  Tue Jun 24 17:39:13 2025, Carsten, Stefan, Simon, Rima, Nils, Detectors, PMT behaviour - noise / PMT voltages / CFD Threshholds / CAEN Power supply (broken channel resetted) 
PMT North and South have been changed:

CFD CH0: Middle Thr 7 / CAEN HV Ch1: 2750 V
CFD CH1: South Thr 8 / CAEN HV Ch2: 2700 V
CFD CH2: North Thr 8 / CAEN HV CH3: 2800 V

MESY CFD Ch4: Thr.17
MESY CFD Ch5: Thr.16
MESY CFD Ch6: Thr.20


Quote:
In position North there is still the "old" 9423B PMT that draws quite some current.
On this detector threre is also some quite substantial noise. Very likely the base is not ok any more. Noise was much lesss for the other two PMTs.
Since position NORTH is the position with the largest sold angle, if there is another break from the accelerator we should exchange it against SOUTH.
It was also difficult to ramp up PMT north ; and I thought that againa channel broke (showing UnV not OVC (Overcurrent)). However, the PS is resetted if
you switch of the whole crate (aka switch the PS off). Before doing so, please ramp down the other channels slowly as intended.


Please leave the PMTs (besides you go in to exhchange the PMTs).
If you ramp pt PMT North (or the same detector at a different position), start with 2400 V and then slowly increase by steps of 50V.

Checked theresholds (but during injections, so in presence of electronic noise from injection). A further adjusted might be done later when we have measurement conditions.
(Or if we have time to exchange the PMTs).


Presently we have the following settings for CAEN:


CH1: Middle 2750 V, Thr 9
CH2: South 2700 V, Thr 7
CH3: North 2800 V, Thr 9
Entry  Tue Jun 24 15:44:06 2025, Konstantin, DAQ, Phase shift in DAQ1 
In the SetParameters.C file is a parameter called fPar->piPhaseOffset. It was shifted from 100 to 50 in order to see ion bunches in the pmt signal and laser pulses in the photodiode signal during the same revolution in the TDC spectrum. Note that this parameter must be taken 
into account when setting the window conditions of the arrival time in the SetConditions.C file. 
Entry  Mon Jun 23 18:36:39 2025, Wilfried, Simon, Detectors, PMT test with LED 
We tested the PMTs again, this time with an UV LED that is mounted at a window close to the XUV detector.
PMT south showed a very clear increase in count rate from about 1 to 50 Hz.
PMT mid also showed a small increase by a few Hz.
For PMT north there was no great change between LED off and on, but we think that the count rate also very slightly increased. Note, that PMT north is also the furthest away from the LED.

Also we saw a difference between single- and multi-photon events at PMT south.
Entry  Mon Jun 23 10:59:36 2025, Julian, Lukas, Zsolt, Nadine, Konstantin, Runs, Scan routine 
-Start new injection
->wait for 60 injections to be complete
->note down SIS intensity (at extraction)
->observe Schottky to ensure proper bunching
->check laser position (should be well-centered)
-open file, start Go4
->do '@openfile' in both mbs windows
->start acquisition (green arrow) in both Go4 instances (check indicator 'Current Ev/s' at the bottom, should be green, not red)
->start laser scan
->reset Ch3 of the particle detector (in the electronics hut)
->check laser position (disappears at start of scan then drifts through the image from the left)
-when laser scan is finished:
->stop Go4 acquisition (big red 'STOP' button in the top row)
->do '@closefile' in both mbs windows
->check counts on particle detector
-update elog
-repeat
Entry  Mon Jun 23 10:52:34 2025, Julian, Lukas, Zsolt, Nadine, Konstantin, Laser, Frequency conversion unit 
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. 
Entry  Mon Jun 23 01:01:17 2025, Carsten, Detectors, CAEN PMT Power supply 
Since yesterday, channel 0 of the CAEN PS is dead (no voltage even without cable).
Changed detector south to channel 3.
Entry  Sun Jun 22 23:48:35 2025, Carsten, Accelerator, Summary of todays settings and tests  
Scraping, beam intesnity optimizations and nuching were set up and optimized during the day.

Initial findings

  • Very long cooling times are needed after deceleration to cool the decelerated beam.
  • Electron energy and decelerated beam are not well matched.
  • 229Th is cooled even later after the other ions
  • Even after scraping some contaminats remained that were either rebunched and show side bands. or move around as a "cloud".
  • This can be seen on the detectors (e.g. particle dector, but also PMTS) as a flat bump in the folded "accu" spectra. the signal decreases with time. I.e., It moves around the ring with a frequency matching the one of the wanted species but with some "phase offset" of about half a ESR revolution. The signal is ratger stron but vanishes ("decays") after some time. Probably finally scraped og
  • It is very tigth to set the scrapers correctly (and the particke detector).
  • Fortunately the ion beam optical setting is such that the scraper in the south is in optimal position just at its "Endlage inne" (values see below)
  • SIS intensiteis have increased but are still on average a factor 3-4 lower than one year ago.
  • As a sidenode: For optimal scraping, the beam decelerated, debunched, cooled, scraped and rebunhced. Thus, one can see if there are contaminants, and, in consequence clean the beam better from unwanted species.
  • The bunches are still quite long given the number of ions, increasing of the bucket fill from 1.0 to values large than 1.4 gives problems such as phase shifts , ande changes even inbetween a waiting/measurement time. to be discussed with the specialists on monday

Mitigation Solution

  • The cooling energy is set 100V higher - which also matches better to a recalculated scanning range; ( PTB 104513 V, Ohmlabs 1040509 V). This better matching improves cooling times but is till not optimal. It is noted, tha tthe cooling times are long since a broad cloud of ions is decelerated, and the electron current is low (was 50 mA, now 60 mA).
  • Electron current increased 50 mA -> 60 mA.
  • Scrapers are moved in in two steps with an intermediate posiions to mitigate the problem of overshoots when driving. Before rebunching they are slightly moved out to make room for the slightly larger
    bunched beam.
  • Due to the change of the voltage the bunching frequency has changed (see post of the start of the test measurements); electron cooled DC beam and bunched beam are (alomost) matched using the RSA in 100kHz scale. The new reference frequency on the RSA are (old: 243.750625MHz, rev. frequency 1.542728 MHz, 158 harm - new: 243.815 MHz, 1.54313 MHz).
    [New settings for timing and scraper position will be attached as fotos; an emergency backup of the settings are stored in an earlier post).
  • The cooler actually drags the ion very slowly to its final position after ~30 s just before rebunichng (visible by the shift of the peak relative to the marker just before rebunching). This is interpreted as and effet of the power supplies only very slowly reaching a final value to within a few kHz.
ELOG V3.1.5-fc6679b