 Tue May 4 17:54:08 2021, Helmut Weick, Simulations, updated LISE file 
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This file really has the optics like used in the last ESR experiments.
Now the transmission is also a little bit better. |
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Tue May 4 18:25:31 2021, Helmut Weick, Simulations, cutting of primary beam
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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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Tue May 4 21:49:04 2021, Helmut Weick, Simulations, cut Brho by scrapers
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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.
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Thu May 6 00:32:57 2021, Helmut Weick, Simulations, GICOSY file for TE beamline and ESR
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This file has several options:
start in SIS, at TE3UF target or inside ESR, choose with GOTO LABEL (G L)after start system (S S).
Depending on the choice select different start beam parameters at top of file, others comment out.
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Thu May 6 13:26:56 2021, Helmut Weick, Detectors, TE5 profile grids do not work
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There are several issues.
1. The stepper motor drive does not react from Device-Control, -> check controller in FRS Messhütte
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Thu May 6 14:28:32 2021, Helmut Weick, Calibration, Be target thickness calibration -> 1839 mg/cm^2
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Injection was optimized before with Cu-40 mg/cm^2 stripper.
This reduces energy of 78Kr from 370 MeV/u -> 386.52 MeV/u.
To keep the same ESR injetion the SIS energy was raised with Be 10mm tatget.
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Fri May 7 01:07:27 2021, Helmut Weick, Analysis, maybe frequency ID
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We think we see the frequency range of A/q=2.25 at 243.1 MHz.
This would correspond to L=108.2m and E=386.4 MeV/u (gamma_t = 1.3955) at h = 126.
Path length is a bit short, for L=108.4m it should be 370.6 MeV/u.
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Fri May 7 03:44:55 2021, Helmut Weick, Accelerator, scraper optimisation
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Opened TE4 slits again to +/-10mm.
Then we tried different scrapers:
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Sat May 8 01:33:25 2021, Helmut Weick, Simulations, frequency list for 70Se setting
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EXCEL table with all possible fragments injected into ESR.
The path length in ESR, gamma_t and harmonic are adjusted to the 72Ge data.
Some lifetimes are limited but all intense lines are >30s in lab system.
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Sat May 8 01:43:23 2021, Helmut Weick, Accelerator, 70Se setting
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If gamma_t = 1.3955 Tm stays, we will need Brho = 6.21902 Tm for 70Se.
The corresponding ESR Brho setting will be a bit shifted.
It then requires E-SIS = 446.55 MeV/u to get 70Se to this Brho and gamma_t.
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Sat May 8 16:08:58 2021, Helmut Weick, Accelerator, beam position of Kr before ESR
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Checked beam positions in beamline before ESR,
they all look the same as before, with direct Kr beam.
Compare with old elog entry #.
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Thu Jun 24 22:05:11 2021, Helmut Weick, Accelerator, LISE files for 72Ge, 70Se, 52Mn settings
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This is just a Brho selection by the ESR based on SIS-energy used,
energy-loss in target with calibrated thickness and momentum spread by the reaction (Goldhaber formula).
Production cross sections are by EPAX 3.1 |
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Sun May 9 01:19:47 2021, Helmut, Sergey, Accelerator, scraper optmisation for 72Ge
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To improve the isochronicity still in the 72Ge setting sextupoles and scrapers wer varies successfully.
1. E02DS_H -130 / 130mm - wide rect. peak
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Sat May 8 21:08:13 2021, Helmut, Sergey, Shahab, Wolfram, Yuri, Accelerator, optimisation of sextuples
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| The optimisation of sextuples is finished. Record a few files. |
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Sun May 9 01:49:25 2021, Helmut, Sergey, Yuri, Accelerator, change to 52Mn
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It was done in steps:
isochronous 52Mn should come at Brho = 6.28239 Tm (gamma_t = 1.3955).
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Tue Jun 29 20:13:58 2021, Helmut, Sergey, Yuri, Accelerator, change to predrilling an 72Ge
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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)
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Sun May 9 18:50:23 2021, Helmut, Wolfram, Yuri, Accelerator, changed to 70Se
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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
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Sun May 9 21:29:26 2021, Helmut, Wolfram, Yuri, Accelerator, target TE3UF shift
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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.
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Sun May 9 22:31:23 2021, Helmut, Wolfram, Yuri, Accelerator, change to 72Ge
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we change back to 72Ge
just change SIS-energy E = 441.0 MeV/u
beamline energy after target E = 392.9 MeV/u
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Sun May 9 23:24:49 2021, Helmut, Wolfram, Yuri, Accelerator, scraper optmisation for 72Ge
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We tried the scrapers a bit, because right of peak some background appeared.
The GE01DS_HI shows a strange effect,
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