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  nuclear two-photon decay, Page 9 of 12  Not logged in ELOG logo
ID Date Authordown Category Subject
  186   Thu Jul 1 23:46:17 2021 IrisGeneralLess beam after gas bottle change?
Looks like there is a bit less beam now in the ring. I just looked at one spectra from before the gas bottle change and after...
  187   Thu Jul 1 23:54:43 2021 IrisGeneralLess beam after gas bottle change?
No, everything okay! Must have had a very good earlier run to compare.

> Looks like there is a bit less beam now in the ring. I just looked at one spectra from before the gas bottle change and after...
  188   Fri Jul 2 00:08:22 2021 IK, KanikaDAQNTCAP status
The latest recorded tdms files:
 p:\E143\sc\SC_2021-06-30_23-27-45\0000338
 p:\E143\iq\IQ_2021-06-30_23-27-34\0001651
2. The rest space on the drive "p:\" : 28,4TByte
  197   Fri Jul 2 04:58:39 2021 IK, KanikaDAQNTCAP status
The latest recorded tdms files:
 p:\E143\sc\SC_2021-06-30_23-27-45\0000405
 p:\E143\iq\IQ_2021-06-30_23-27-34\0001978
2. The rest space on the drive "p:\" : 27.1TByte
  184   Thu Jul 1 23:07:47 2021 IK, KKRunssource
The change of the source happens now
  185   Thu Jul 1 23:38:55 2021 IK, KKRunsChange of gas bottle
The gas bottle has been changed and the beam is back.
  191   Fri Jul 2 01:39:51 2021 IK, KKRunsdrop of intensity
We see a drop in beam intensity from 7E9 to 2E8 between 01:30 and 01:43
  192   Fri Jul 2 01:43:56 2021 IK, KKDAQNTCAP status
The latest recorded tdms files:
 p:\E143\sc\SC_2021-06-30_23-27-45\0000360
 p:\E143\iq\IQ_2021-06-30_23-27-34\0001759
2. The rest space on the drive "p:\" : 28TByte
  194   Fri Jul 2 03:10:03 2021 IK, KKRunsdrop of intensity
We see that intensity stabalized at 9E8 which is smaller then before. 
We neticed this at 2:50, keep observing.
  195   Fri Jul 2 03:19:49 2021 IK, KKRunsdrop of intensity
And the intensity is back again to 5E9 at 03:20
  205   Fri Jul 2 11:44:25 2021 Helmut, YuriAcceleratormove scrapers to see effect on unknown lines
We close the arc inside and straight section inside scrapers to narrow and cut the 70Se line.
Then look what the other lines left of 70Se will do.

1st series with E01DS_HI
 -58  - intensity as before
 -52  - still as before
 -50  - still full
 -45  - less intensity but about same width
 -40  - almost gone 
   0  - gone
 -58  - back to old position

2nd series with EEXDS1HG
 16.0 - full
 15.0 - full
 12.5 - less
 10.5 - less intensity
  9.7 - appears only sometimes
  8.2 - gone
 10.8 - middle intensity and more narrow, measure for a while
  110   Sun May 9 18:50:23 2021 Helmut, Wolfram, YuriAcceleratorchanged to 70Se
18:45  changed SIS, ESR setting for 70Se without predrilling blind change.
E-SIS =  446.55 MeV/u, is centerd as before on TE3UF target grid.
set beamline after taret as 78Kr 36+ E = 337.375 MeV/u
set ESR to A = 70, Z=34 at isochronous E/m + 0.8 MeV/u = 369.2 MeV/u
kicker delay unchanged

4 quadrupoles failed during the change, skip cycle and reset, they work again, (GE01QS0D, GE01QS1F, GE01QS2F, GE01QS4F)

Now many lines in Schottky.

also 2 corrector coils were off, on again, now good resolution.
  114   Sun May 9 21:29:26 2021 Helmut, Wolfram, YuriAcceleratortarget TE3UF shift
We see a very strong line at the left end of spectrum, stronger than all other lines.
When we shift the target TE3UF_H from -35mm to -37mm it gete weaker, but -37mm is the end of drive.
In the other direction it becomes worse. At -25mm completely new peaks.
Also scan in Y direction TE3UF_V +25mm and +40mm give other fragments even very intense, while the old lines vanish.
So production happens in target frame. 
Use -37mm, +37mm as best target position.

We run with TCap only for some time hoping there is somewhere a peak of 70Se
running from about 9:15 to about 22:00
We set scrapers in the previous optimum position
  115   Sun May 9 22:31:23 2021 Helmut, Wolfram, YuriAcceleratorchange to 72Ge
we change back to 72Ge
just change SIS-energy       E = 441.0 MeV/u
beamline energy after target E = 392.9 MeV/u
set ESR to A=72, Z=32 (72Ge)
--> good injection and resolution in ESR, at old frequencies
  116   Sun May 9 23:24:49 2021 Helmut, Wolfram, YuriAcceleratorscraper optmisation for 72Ge
We tried the scrapers a bit, because right of peak some background appeared.

The GE01DS_HI shows a strange effect,
normal -65mm gives good resolution, -30mm kills the beam, but even more in at -15 there is beam again.
We suppose the scraper is not massive but has an empty space behind it.
GE01DS_HA has no effect even at +0V.
Therefore, put I to -100mm and also use GE01DS3HG (from outside),set to -55mm.
Then also the straight section EEXDS2HA from + 8mm to +10mm (a bit more closed).
  86   Sun May 9 01:49:25 2021 Helmut, Sergey, YuriAcceleratorchange to 52Mn
It was done in steps:
isochronous 52Mn should come at Brho = 6.28239 Tm (gamma_t = 1.3955).
set ESR to m/q and E for 52Mn, 368.41 MeV/u

1.) predrilling 1st try
- set beamline to E, q for 52Mn and m = 51.9319 u by trim
- E-SIS = 422.1 MeV/u
but then not centred on profile grids, with thick Be target in 
-15mm on TE4DGC also not on Lecuhttarget, not good


2.) pre-predrilling 2nd try
don't set beamline for 52Mn but define it as 78Kr, in trim mass back to 77.92 u.
insert Cu-40 mg/cm² and inject, just use dE = 1.5 MeV/u in stripper for SIS-energy (343.353 + 1.5) MeV/u 
optimise a bit, then keep beamline energy set as 78Kr36+ beam the same. 

3.) pre-drilling 422.1 MeV/u in SIS
insert Be target and optimise with kicker and septum angle,
energy also tried but back to old value, reache 6 - 7 % transmission

4.) change E-SIS to 440.7 MeV/u to get 52Mn in ESR at gamma_t
  138   Tue Jun 29 20:13:58 2021 Helmut, Sergey, YuriAcceleratorchange to predrilling an 72Ge
After optimisation of sextupoles we found a scraper position which makes a narrow peak and keeps 20% of the injected beam.
  GEEXDS2HA = +2.0 mm (out is +130mm)
  GE01DS_HI = -75 mm  (out is -130mm)
removed scrapers again for predrilling.

We agree on gamma_t = 1.3956, E/m = 368.50 MeV/u.
Then for 78Kr at Brho = 6.79675 Tm of isoc 72Ge 
E-SIS = 466.63 MeV/u, assume target of 1815 mg/cm² Be
after target E/m = 393.024 MeV/u
In ESR-Modi set for same E/m but different m/q (m=72, Z=q=32)

Injection looks good like before with isochronous 78Kr we go directly to the next step
72Ge with E-SIS = 440.16 MeV/u to get 72Ge at gamma_t.
  80   Sat May 8 21:08:13 2021 Helmut, Sergey, Shahab, Wolfram, YuriAcceleratoroptimisation of sextuples
The optimisation of sextuples is finished. Record a few files.
  85   Sun May 9 01:19:47 2021 Helmut, SergeyAcceleratorscraper optmisation for 72Ge
To improve the isochronicity still in the 72Ge setting sextupoles and scrapers wer varies successfully.

1. E02DS_H -130 / 130mm  - wide rect. peak
            -30 / 130    - nothing 
            -35 / 130    - weak but broad
            -70 / 130    - wider rect peak
            -70 / 30     - two peaks
            -70 / 10     - peak + small peak
            -70 / 0      - peak  + tiny peak
   cannot move more than 0, back to 
            -70 / 50

2. E01DS_H: -130/130    -   wide rectangular distribution
             -40/130    -   wide double structure
             -35/130    -   very weak, still double structure
 some sectupole tuning
             -40/0      - nothing
             -50 / 0    - peak with right tail
  cannot close outside more than 0 so try next scraper

3. E01DS3HG
  -130  - peak with long right tail
   -30  - nothing
   -50  - peak with long right tail
   -40  - weak peak with long right tail
  ==> no good scraper do not use

4. EEXDS2HA
   -120   - peak with long right tail
    -20   - peak with long right tail
      0   - peak with less right tail
     10   - small peak, no right tail
      5   - smaller peak, no right tail
      3   - smaller peak, with small right tail
      8   - small peak no tail
  ==> good scraper use it (+8mm)

5. Try a bit more on E01DS_H
  -55 / 0  - small peak no tail
  -55 / 50 - same no loss in resolution
  -55 /130 - same no loss in resolution
  -65 /130 - same good peak, but higher intensity
  -75 /130 - same good peak, but left tail
  -65 /130 - same good peak, no tail

6. open E02DS_H to -130 / 130 no difference 

7. again E01DS_H
 -125 /130 - very wide left tail
  -68 /130 - one peak
  -72 /130 - one peak, samll left tail
  -66 /130 - one peak, no tail
 ==> good scraper use it (-66mm)

8. check all other scrapers they are all open
   also open TE4 slits to +/-20mm, no difference, back to +/-10 mm

9. bit more sextupole variation on the narrow line

===>  only two scrapers used 

   

picture shows result afterropimisation, the markers indicate the lines,
the left marker is for a +691 keV isomer.








 
  2   Wed Apr 28 09:36:39 2021 Helmut WeickSimulationsLISE file for fragments from TE3UF into ESR
Uncooled beam on target at TE3UF with dispersion and slit in TE beamlne and realistic injection into ESR.
Now tuned for 72Ge but can easily be modified to other fragment settings. 
The target thickness may need adjustemet after measurement.
The attched powerpoint file explains the settup a bit more.
ELOG V3.1.5-fc6679b