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  nuclear two-photon decay, Page 9 of 12  Not logged in ELOG logo
ID Date Author Category Subjectup
  35   Fri May 7 07:52:12 2021 Ragan, AndrewGeneralTo change trigger position
Xiangcheng suggested to change the trigger position in order to start the file with the injection. Nothing is changed at the moment. Maybe Shahab or Yuri can do it when they arrive.
  37   Fri May 7 08:55:33 2021 Ragan, Andrew, YuriGeneralTrigger changed
Trigger for both the spectrum analyzers is changed from 50% to 1% by Yuri.
For this, the ESR pattern was stopped at 08:50 and was started back at 08:53.
  98   Sun May 9 06:15:09 2021 Iris, Chris G., Jacobus, MicheleRunsTriplet: zoom in
Zoom into the triplet: the satellite peaks on the right are clearly visible.
This is just one file but one *might* see some substructure. Yuri mentioned a 318 ms isomer in 45Sc at 12 keV but that cannot be resolved.

Maybe someone can look at the added-up ROOT files if that looks better or is just statistics?

> Short update from Yuri: these are not our isomers. These are 45Sc (left, 12 keV isomer not resolvable) and 75Br (center), and the right-most peak of the triplet is a satellite (has a different line shape, much narrower).
> 
  56   Fri May 7 19:56:10 2021 Kanika, Michael, ShahabRunsZOOM session restart
restart zoom session
  69   Sat May 8 07:34:08 2021 Akash, Nic, Jelena, ZsoltGeneralZoom has its own mind
Zoom kicked us all out... we managed to get back in...screen sharing is back on.
  125   Mon May 10 01:34:37 2021 Chris CGeneralZoom screenshot
How things look currently in Zoom-world.
  167   Thu Jul 1 14:47:15 2021 Yury, HelmutAcceleratoradded high Brho scrapers
So far only scrapers for low Brho were used:
  GE01DS_HI = -58mm (arc from inside) and
  GEEXDS2HA = -11.2 (straight from outside)
We also want a cut on high Brho to avoid possible strange lines.

GE01DS_HA is limited in motion, at the maximum inside position (0.0 mm) there is no effect.

Next EEXDS1HG (aperture for ToF-detctor) in mm
120 -  completely out
 60 - no effect full beam
 45 -   "
 30 -   "
 20 -   "
 10 - very little beam remaining
  5 - gone
 12 - little beam
 14 - narow but little
 16 - narrow with small tail in left side
 20 - again like full
100 - full (as reference for the eye)

Then similar with E02DSHG in arc dipole in mm
 -130 - full
  -60 - full
  -40 - gone
  -45 - very tiny
  -55 - full
  -50 - less beam
  -52 - similar
  -53 - no difference
  -58 - looks like full

Now add EEXDS1HG again with -16mm, no difference, so keep both in.
==> we cut in arc from both sides and on straight secton from both sides
    Intensity does not look different to scrapers out. 
    It looks like a bit less 70Se in ESR then 1h before, but maybe other reason.
  58   Fri May 7 20:34:27 2021 Kanika, Michael, ShahabRunsback to 15 sec recording
now we are going back to 15 sec operation. Cave M (bio) operation is over
  145   Wed Jun 30 01:38:20 2021 ShahabRunsbeam is back from Linac but not in the ESR
  76   Sat May 8 16:08:58 2021 Helmut WeickAcceleratorbeam position of Kr before ESR
Checked beam positions in beamline before ESR,
they all look the same as before, with direct Kr beam.
Compare with old elog entry #.
Also on Leuchttarget it is in the center like before.
  18   Thu May 6 21:45:30 2021 HelmutDetectorsbeam position on TE5 grids
The two grids do not work very well, one x position is opposite to the other.
But at least a guidance for the future, this was good injection of 78Kr with a thick Be target.
  59   Fri May 7 22:00:36 2021 ChrisAcceleratorbrief beam loss
Brief interruption in beam, ~21:42-21:51.
  55   Fri May 7 18:43:13 2021 Kanika, Michael, ShahabRunscave M experiment needs more spills
our pattern causes beam loss while scanning the biological probes in the Cave M bio experiment. They loose every other spill due to high request rate from ESR.

For the next 2 hours, the operators have changed the spill pattern that as long as they are scanning , we get only every 1 minute, otherwise we get our 15 seconds as usual.

after two hours this situation should be tuned back to the original spill pattern.
  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
  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
  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.
  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.
  137   Tue Jun 29 10:32:10 2021 Sergey, HelmutAcceleratorcooler curves for tuning of isochronicity
Variation of quadrupole E01QS03D to change gamma_t in isoc. mode
measured with 78Kr at 368.5 MeV/u on 28.06.2021 evening.
The shape of the three curves looks very similar they would only require a different beam velocity.
But I suppose we stay with the value close to the old one (gamma_t ~ 1.3956).
  6   Tue May 4 21:49:04 2021 Helmut WeickSimulationscut Brho by scrapers
The dispersion from the production target into the ESR is not matched.
This is not good for momentum acceptance, but we anyway want to cut the acceptance.
Dispersion will oscillate with the tune of ESR. After 3 turns we expect a maximum dispersion. 
The picture shows in red the dispersion curve for dp/p=0.1% and beam envelopes of 10 mm mrad.
So we can use scrapers in north or south arc to cut Brho. It should be done from both sides.
How much? Watch the intensity drop.
Best positions look at plot. Straight section outside for low Brho, arc outside for high Brho.
Could be EEXDS2HA and E02DSH (outside).
  5   Tue May 4 18:25:31 2021 Helmut WeickSimulationscutting of primary beam
The slits at TE4 and TE5 can be used to cut away the unwanted 78Kr beam (see pictures).
We do not want activation of the beamline. 78Kr35+ even has a chance of being injected.
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