attched is more info about the T-scrapers (E-cooler) by Robert Boywitt (Tel: 2067 or 3357)

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

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.

Maximum XUV LED Voltage: 6.5V

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...

The simulated frequency is given in simulation_result.out. The yield is calculated by LISE file. The LISE file is attached here also.

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.

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.

Setup at ESR is carried on - stopped the long-time NTCAP run from overnight,

Lifetime still is short

If the laser controller is locked up again, the little display will show an error message after an attempted medusa scan.
To restart it, follow these steps:
1.) Unlock the beam stabilization.
2.) shut down medusa and the wavemeter software
3.) Turn off the 2 laser stages
4.) Close the shutter of the pumping laser
5.) Turn off and on the power button of the pulsed laser inside of the black box of the pump laser insertion.

To start again go back through the list.

When the ion pumps and vacuum gauges are switched off the scaler data of 
PMT_south, PMT_middle, PMT_north, PD_NO, PD_SO, PartDet North, PartDet South and (Channeltron) should be checked without voltages applied in dependence on the CFD thresholds to determine the "cable noise level" at which thre are NO entries other than 0 in hte spectra (minimum background).

Same for 2nd DAQ and Mesytec MSCF16

To realize the shortest bunches possible, we check the bunch length as a function of two different bunching amplitudes. With the bucket fill set to 1.0 we observe the spectra compiled in attachment 1. The second attachment is recorded with a bucket fill 0f 0.2.

For an RF amplitude of 0.2 we do not observe bunches any more but a coasting beam. In the shottky spectrum we can resolve a shift of the signal and thereby adjust the electron cooler voltage to the bunching frequency to within 1 V.

U_e-cooler = -104410 V
I_e-cooler = 80 mA

What is the ion beam lifetime, according to the DCCT and Schottky? 
Can somebody measure it, please? 
Yesterday we could not see a fast drop in the "main" beam. 

Because the lifetime that is mentioned here is the one based on the particle detector and on the PMT countrate. 
If what is seen now is "only" some fast decaying component inside the beam, we could simply wait for its decay and then continue with the real measurement. 

It seems to be that there are some problems with the injections in the ESR.
The last 2 accumulation cycles showed that wheter only a small amount of ions are injected into the ESR or the injection is missing.

Photos of the last 2 accumulation cycles are attached.

We ask if there are some problems with the ESR or with the SIS18, because the particle number in the SIS18 is also decreasing... 

data:
(env_OnlineDataAnalysisSystem) litv-exp@lxbk0497:/lustre/astrum/experiment_data/2024-05_E018/OnlineDataAnalysisSystem/data/iq/IQ_2024-06-
12_21-47-54$
The root file is at:
(env_OnlineDataAnalysisSystem) litv-exp@lxbk0497:/lustre/astrum/experiment_data/2024-05_E018/OnlineDataAnalysisSystem/data/iq/IQ_2024-06-
12_21-47-54$ root filtered_spectrum_670_750.root

The figure below shows the interface of the program "combine_injection". You can combine any tdms file with this program. To run this 
program, you need to log in to the server /luster/astrum/, and activate the conda environment. Then type the command "combine_injection" at 
the terminal. You will see the interface. 

• The UV LED does not give a useful signal for the small-band VUV PMTs.
  
• In general, (using the new cables?) it seems that the cable noise is very low and can be easily discriminated.
  
• PMT south (the broadband) sees a regular "strong" pulse-train/burst of photon signals. Therefore, the PMT was exchanged against a different one (SolarBlind ET Enterprises Model 9422, SN1042) - same result. New data sheet is attached.
  
• The channeltron has a rather broad pulse height distribution but very low background. CFD thresholds can easily be set. Very likely the best detector to adjust the laser timing?
  
• Channeltron Head : -2.5 kV , CFD threshold 8 mV.
  
• PD SO threshold needs to be checked (in Go4 the number of counts of PD SO is much lower than of PD NO). Present values: both 10 mV.
  
• Voltage PMT north / middle (both small-band) : -2600V, PMT south (replacement): -1500V. All thresholds: 15 mV
  
• CAEN CFD must be switched back to LOCK or it otherwise produces additional background
  

Fcenter - 244.6 MHz
BW - 10 MHz

We changed the dye at ~3pm.

After some fine adjustements of the laser we had to change the MRC settings, because the laser position changed.
Therefore we checked the position of the laser with the T-Scrapers with the settings from post 49 "First Scraper Scan".

New settings of MRC and screen pic is attached.
The position of the laser on the screen is now the 'same' as yesterday (see attachement).

----
The frequency of the primary beam 238U82+ at the injection:
Ucool = -360 V
Frev = 1.974647 MHz without bump
Frev=1.97387 MHz with bump
---
ID:
246 MHz + kHz (+/- intensity) ID
521 +++ 238/92+
565 +.    230/89+
595 +++ 235/91+
642 +.    227/88+
670 +.    232/90+ 
693 +++ 237/92+ (strongest line)
721 +.      224/87+
744 ++.   229/89+ (our Th line)
767 ++.   234/91+
822 +.     226/88+
845 +.     231/90+
867 +.     236/92+
901 -       223/87+
922 +.     228/89+
942 +.     233/91+
1001 +.    225/88+    
1020 ++.  230/90+
1039 +.    235/92+ 
1100 +.     227/89+
1211 + <- far off

The preliminary identification has been thoroughly checked using the RionID software. We have confirmed that the identification is accurate.

Attached can be found the simulation file with each of the expected ions, their revolutions frequencies in the 125th harmonic and expected yield from the LISE file attached.
Also attached are some figures from RionID that highlight the region of interest for the 124th and 125th harmonics. The center frequency of the 245 MHz resonator is closer to the 124th harmonic for 229Th+89 which is located at 244.769 MHz. 

If necessary, we can slightly shift the resonator curve to higher frequencies to fine-tune the signal-to-noise ratio for 229Th+89.

1.) If not already opened, open the Medusa Laser Control software, see picture:
2.) In the "view" submenu, choose "proteus status".
3.) At the bottom of the list, the K250 shows the scaled voltage.

Thanks Jan!

• Controlled automatically by the control system (sub chain patterns)
  
• Set to manual operation during setup or experiment.
  

All quadrupole and dipole magnets at SIS and ESR are out of order. Repairs can be expected earliest tomorrow evening. No shifts will take place before 6pm. Have a look at your mails for details.

Jan exchanged the Mesytec CFD/shper since it could not be "remote controlled" anymore. The new one has different shaping times and delays.
It is noted the threshold range is rather small. 
With the new  shaper only the x100 signals could meaningfully discriminated etc.
After start of the ESR (magnets etc.) the signals of the 10x channels see quite some noise that makes it more difficult to adjust the thresholds for the low signals.

Estimate of storage lifetime using my code 'hydrocal':

 ion mass in u ...................................: 229
 ion nuclear charge ..............................: 90
 ion charge state ................................: 89
 beam energy in MeV ..............................: 45501.1
 beam energy in MeV/u ............................: 198.695
 beam beta .......................................: 0.566309
 beam rigidity in T m.............................: 5.4944
 ring circumference in m .........................: 108.36
 ring acceptance in mrad .........................: 2
 ring temperature in °C ..........................: 25
 ring vacuum pressure in mbar ....................: 3e-11
 residual gas density in m^-3 ....................: 7.28767e+11
 residual gas composition 
  Z   %
  1  93.43
  6   2.23
  7   0.75
  8   3.29
 18    0.3
 cooler length in m ..............................: 2.5
 electron current in A ...........................: 0.2
 magnetic expansion factor .......................: 1
 electron-beam diameter in mm ....................: 50.8
 electron density in cm^-3 .......................: 3.62844e+06
 cooler cathode temperature in meV ...............: 110
 cooling energy in eV ............................: 109000
 space_charge (0th iteration) in eV ..............: 44.3477
 space_charge (1st iteration) in eV ..............: 44.341
 transverse temperature in meV ...................: 110
 longitudinal temperature in meV .................: 0.2
 RR nmin .........................................: 1
 RR lmin .........................................: 0
 RR nele [no. electrons in subshell (nmin,lmin)] .: 1
 RR nmax .........................................: 128
 RR enhancement factor ...........................: 2.5
 RR alpha in cm^3 s^-1 ...........................: 8.04602e-08

 beam lifetime due to multiple scattering in s ...: 1.86e+06
 beam lifetime due to single scattering in s .....: 7.51886e+07
 beam lifetime due to charge capture in s ........: 3.5516e+06
 beam lifetime due to stripping in s .............: 1e+99
 beam lifetime due to recombination in cooler in s: 148.466
 beam lifetime with electron cooling in s ........: 148.46
 beam lifetime without electron cooling in s .....: 1.20121e+06

 detector count rates for 1E6 stored ions and a residual gas pressure of 3e-11 mbar: 

       recombination detector from ecool (Hz) ....: 4575.41
     recombination detector from res.gas (Hz) ....: 0.0545666
    total rate on recombination detector (Hz) ....: 4575.46

        ionization detector from res.gas (Hz) ....: 1.93798e-94

No beam today.--.

Calculation from Helmut Weick (copied from E142)
Distance e-cooler to particle detectors chamber:
“This is half of ESR plus distance target - detector. This even is on the web page”
54.28 m + 21.64 m

Cooling Time in SC7 increased from 9s to 12s

On the CAEN V1290N TDC the piggy board for the lower 8 channels is not fixed well to the motherboard.
That prevented to the whole DAQ2 to trigger correctly or even crash every once in a while. Long attempt sot find the error in hard and in software.

I fixed/reattached the piggy board, but be careful with the attached Lemo cables. They might loose the board again (it used to fixed with hot glue).

DAQ2 now also seem to run smoothly.