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  Nuclear hyperfine mixing in 229Th89+ 2024, Page 1 of 4  Not logged in ELOG logo
ID Date Author Category Subjectdown
  22   Thu Jun 6 08:16:36 2024 DanyalAcceleratorscraper info by Robert Boywitt
attched is more info about the T-scrapers (E-cooler) by Robert Boywitt (Tel: 2067 or 3357)
  7   Fri May 31 15:53:06 2024 Ruijiu ChenDAQrun NTCAP system
NTCAP is working again. 
Connect the RF cable and the scaler cables to NTCAP system.
The map of signal is recorded in following link. 
https://elog.gsi.de/esr/E0018/2
Test it with IQ rate of 10 MSamples/s.
E0052/IQ_2024-05-31_15-04-34 
E0052/SC_2024-05-31_15-04-34
  Draft   Thu Jun 6 07:54:15 2024 DanyalGeneralpressure gauges and ion pumps
yesterday (05.06.2024), firstly, the two ion pumps (underneath the fluorescence chamber) were switched off by the vacuum group (Björn Mai, Tel: 3438). Secondly, the two pressure gauges (located near the target) were switched off.  The pressure gauge at the fluo chamber is called E02VM3x and the pressure was 5.5e-11 mbar.  The other gauge is called IG2 and located further south, it measured 3.7e-11 mbar.  That was when ion pumps were still switched on.  Since ~10:45 (05.06.2024), the two ion pumps and the two ion gauges are switched off. There was no measurable change in the pressure after switching off the ion pumps.
  32   Fri Jun 7 17:10:45 2024 SebastianGeneralXUV LED
Maximum XUV LED Voltage: 6.5V
  8   Fri May 31 16:49:52 2024 CarstenDAQWiring DAQ 1
Started to Check the wiring.

Status as of 2024-05-31

Inputs into 1. DAQ /TDC/Scaler - List according to file TLdaInputDescription.h in directory ~/go4/229Th

Cobra_Busy, // 0:
Next_Laserstep, // 1:
Laserscan_Complete, //2 :
{"PMT_South", 3, {3,11}},
{"PMT_Middle", 4, {4,11}},
{"PMT_North", 5, {5,11}},
{"Empty0", 6, {}},
{"ParDet_South", 7, {}},
{"ParDet_North", 8, {}},
{"QSwitch_500us", 9, {}}, // Important to mitigate missing Q-Switch
{"EmptyA", 10, {}},
{"Channeltron", 11, {9}}, //not yet wired
{"Bunch HF", 12, {}}, //not yet wired
{"PD_NorthEast", 13, {}},
{"PD_SouthEast", 14, {}},
QSwitch, //15
DC_Trafo, //16
{"Injection", 17, {}},
U_ECooler, // 18
I_ECooler, // 19
{"P_Gun", 20, {}},
{"P_Coll", 21, {}},
{"Common_Stop", 22, {}}, //? P_coll two times????
Clock_1MHz, // 23
{"Empty1", 24, {}},
{"Empty2", 25, {}},
{"Empty3", 26, {}},
{"Empty4", 27, {}},
{"Empty5", 28, {}},
{"Empty6", 29, {}},
{"Empty7", 30, {}},
{"Empty8", 31, {}},

Checked also the connections from the CFD to DAQ 1 (ok)
input connections to CFD are as labelled on the black laser Messhütte panel

CFD channels:

0: PMT south
1: PMT niddle
2: PMT north
3: PMT copper (not used)
4: PD NO
5: PD SO
6: Part Det South
7: Part Det North
8: empty
9: XUV front (not used)
10: XUV back (not used)
11:
12: Master Osci Bunchng HF (Süd)
13: empty
14: empty
15: Master Osci Bunchng HF (Nord)

PD_NO and PD_SO are terminated with 50 Ohm at input (conflicts with 50 Ohm input termination of CFD)
  43   Tue Jun 11 21:38:35 2024 Julian, Imke, RodolfoLaserWavemeter HeNe long time stability
The HeNe was running over night and the measured laser frequency of the wavemeter was logged, see picture.
A significant drift of around 300 MHz is visible during the night.
It is possible, that the laser lab got too cold during the night, as the pulsed laser was not running.
For now, we put the wavemeter in a thermoinsulator box...
  29   Fri Jun 7 09:15:31 2024 CarstenDAQUpdated Channel List
  39   Mon Jun 10 09:17:38 2024 CarstenDAQUpdated Channel List
  30   Fri Jun 7 11:14:04 2024 RodolfoLaserTrigger-signal for MRC
We are using a 2-Channel Function Generator (from Textronik) to generate the trigger signal for the MRC Beam Stabilization.

The triggers are (according to the MRC nomenclature):
- Tmin = 500 us.
- T1 = 40 us.
- T2 = 460 us.
  51   Wed Jun 12 17:12:13 2024 Julian, Danyal, RodolfoLaserTiming für 229Th89+
We did the timing Ion-Beam Laser-beam time overlap.

The ion revolution frequency (and therefore the bunching frequency) is: 1.5429 MHz.
  24   Thu Jun 6 09:23:53 2024 Konstantin MohrDAQTiming
The best way to adjust the bunch-laser timing is to start go4 (mbs must be running) from atppc023. Therefore use x2goclient and use the predefined session to access LXG1297. Start go4 as usual (Entry 10 + Entry 11).

With this preparation one can directly observe changes in the relative time between the common stop trigger and the photodiode signals (see Screenshot 3) when rotating the upper channel's fine adjustment wheel of the right dual timer above the laser table (see Screenshot 2, Don't touch the coarse adjustment wheel directly above!!!).

To ensure proper operation of Go4 make sure that it is closed in the ssh-session after the correct timing has been set!!!
  40   Mon Jun 10 11:59:12 2024 Ruijiu ChenAnalysisThe ion identification of spectrum recorded on 2022
The simulated frequency is given in simulation_result.out. The yield is calculated by LISE file. The LISE file is attached here also.
  71   Thu Jun 13 18:48:26 2024 Ruijiu Chen, David, Shahab, YuriAnalysisThe ion identification of 229Th is correct.
Harmonic: 124.0 , Bp: 7.796046 [Tm]
ion            fre[Hz]                       yield [pps]    
------------------------------------------------------------
237U+92        243732740.7822311819          8.6164e+03     
237Np+92       243732858.1891748905          1.9672e+02     

224Ac+87       243759120.6575988531          1.7025e+03     

229Pa+89       243784072.1343108118          2.5529e+03     
229Th+89       243784111.0000000000          3.3883e+03   
  
234Pa+91       243807737.9699291289          2.4721e+03     
234Np+91       243807852.4158236086          1.7745e+01     

The strongest line is 229Th+89/229Pa+89. The yield and frequency of 229Pa+89 and 229Th+89 are very close to each other.  We needed to 
install Al target to suppress Pa as much as possible. Al gives a better ratio of h-like to he-like than Be. Two peaks at left 
side are 237U+92/237Np+92 and 224Ac+87. One peak at right side is 
234Pa+91/234Np+91. 

Note added 2024-06-14 (Carsten): a) We will not produce Np, this is an artifact of Lise, b) relative intensities are for injection only. Line intensities for  237U/224Ac/234Pa are substantially lower after cooling/HF/deceleration.
  47   Wed Jun 12 09:17:43 2024 Carsten Tests of background with ionization pumps on (from monday)
On monday the ionization pumps were switch on to test the background, and if it is possible to run with the pumps switched on.
Results and comments, see below:

Later some data were recorded with DAQ1 to allow for a more thorough analysis - beam is 238U38+ at 401 MeV/u - file 0013
Please note the data of this file was recorded after the figures below were taken.

In short, we have switched off the the ionization pumps because the conclusion is somehow ambiguous. Background rates from real photons are considerably low at ~5Hz and 10Hz for the small-band PMTs (see figure), Yet, PMT south goes up to 350 Hz and sees a lot of photons from the plasma discharge. The few Hz of the small-band detector would be suppressed by the length of the ion bunch / full lenght of the ring. But what is not known is how much it would actually influence the local vacuum of the ring.

Semjon Strohmenger also checked that the valve to the turbos in front and behind the gas-jet is open (--yes). They are running the whole beam time.
I exchanged the prepump at a pocket located between gas-jet and VUV detection set-up. Here after baking a leak was found, and the pocket was pumped with an "old" prepump.
Vacumm in the pocket was ~1mBar. Installed a more powerful Edwards XDS i10. When we left ESR the pressure in the pocket was already at low 10^-2 mbar and still decreasing.
May be this helps to improve local pressure.
  33   Sat Jun 8 12:02:20 2024 CarstenDetectorsTest Particle Detectors - Det South not working
With the test beam from ESR I started to have a look at the PartDets.:
North outside: Works properly with a voltage of 1450 V
South outside (behind cooler) : no signal.

Later (when Danyal is here) we will check detectors cables etc., and if required put the north detector to position south and mount the untested (newly made, but with "old" material and PMT) spare detecotr to poistion north.
  34   Sat Jun 8 12:45:05 2024 CarstenDAQTemporary change of RF signal
The setting was 1.540974 MHz and division factor 68 (for a 200 MeV/u) beam, and the signal was taken from a signal generator.
I now switch to the "real" RF signal from the accelerator (~400MeV/u), that is 1.9693 MHz and the factor is set to 88.
This should be set back for laser tests or adjusted when we have the real decellerated beam.
  20   Thu Jun 6 07:12:49 2024 Konstantin MohrLaserT-Scraper
The T-Scrapers can be driven by DeviceControl, which must be started from a console. To do so, first open the app-launcher and then select "Device Control", which is found under "Betrieb & Steuerung". Then select the appropriate context (should be the name of the experiment). After a short time the device icons will be present. The scrapers can be found in the last four columns and the second last row (see screenshot 1). By default, they should be colored like the following: DS1VU: green, DS1HA: yellow, DS2VU: green, DS2HA: yellow.

To test the scrapers, I made a measurement of the current laser position.

motor laser position (mm) screenshot
DS1VU (GECEDS1VU) 0 2
DS1HA (GECEDS1HA) -10 3
DS2VU (GECEDS2VU) 2 4
DS2HA (GECEDS2HA) -8 5


Note that the interlock of DS2VU is overridden when DS2HA is at 3mm. The interlock of DS1VU is overridden when DS1HA is at -4mm. The horizontal scrapers can only be moved when the corresponding vertical motors have reached their inner end positions.

Compared to the last position of Bi the horizontal and vertical positions deviate by approximately 5mm at all axes. However, since the electron cooler was completely dis- and reassembled in the meantime, it seems to be a reasonable starting point.
  58   Thu Jun 13 10:06:35 2024 Constantine, Peter, Lukas, Jonas, Dounia, CarstenAcceleratorSuspected Beam Troubles (is it really 229-Thorium?)
From experience, the lifetime of the beam in the storage ring should be on the order of magnitude of hours, however, we observer beam lifetimes of the order of 10ish minutes. This suggests either a beam loss mechanism, a totally wrong species or a combination of both.

Yesterday (Elog entry 46) it was verified that the main beam is indeed 229-Thorium in the ESR.

2024-06-13: After discussion (phone) with Markus the lifetimes are reasonable and are dominated by recombination in the cooler.
  31   Fri Jun 7 15:29:50 2024 RodolfoDetectorsStored beam @ ESR
One of the first PMT signals from the stored-ion beam @ ESR
  48   Wed Jun 12 09:43:57 2024 CarstenAcceleratorStopped NTCAP at 9:43
Setup at ESR is carried on - stopped the long-time NTCAP run from overnight,
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