Brief interruption in beam, ~21:42-21:51.

The beam was lost for a few minutes from 23:01 to 23:06. It is back now.

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.

For pre-drilling with 78Kr beam at same Brho use 416.70 MeV/u.
But we could also make a quick try without tuning before, just change all energies.

08.43am: Beam stopped. HKR looking into it. Reason: they mentioned they don't know yet!

10.10am: SIS resumed operations. However, there are some issues with magnet power supplies for ESR and hence we still don't have beam. HKR member went to look for power supply expert.

10.15am: There were some random triggers coming from ESR, which resulted in files being written. To avoid this, the scope trig (both scopes) were taken out. As soon as the beam comes in 'properly', I will reconnect the trig in to the scopes (-akash).

10.40am: They sent something to ESR but it does not make sense...so HKR has called an ESR expert (Sergey).

11.30am: Yuri is here and trying to sort out the issue- no data being written yet.

EO1KP03 was on = -44.9 A
E01KP05 was off, now is on = 3.67 A
The beam is on the right frequency, but the width is still very broad.

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.

The optimisation of sextuples is finished. Record a few files.

Details will follow
E(Mn) = 368.41 MeV/u

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.








 

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

We accept larger m/q values than we like to. m/q(low) cut ~ 2.08. Decrease ESR energy from 369.2 -> 368.4 MeV/u
frequencies shifted by -37.5 kHz (at 60 MHz)

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.

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

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

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).

Here are parammodi saves for TE-line and ESR for all four fragment settings:
For the first run of 72Ge (7.May) I do not have files.

2021-05-09_11-22-51_SIS18_FAST_20210506_ESR_78KR32.C1.txt:# Context: SIS18_FAST_20210506_ESR_78KR32.C1 E143 52Mn
2021-05-09_11-23-12_ESR_EXP21_06_ISO_78Kr_05May21.C1.txt:# Context: ESR_EXP21_06_ISO_78Kr_05May21.C1 E143 52Mn
2021-05-09_15-46-52_ESR_EXP21_06_ISO_78Kr_05May21.C1.txt:# Context: ESR_EXP21_06_ISO_78Kr_05May21.C1 E143 52Mn-2
2021-05-09_15-47-16_SIS18_FAST_20210506_ESR_78KR32.C1.txt:# Context: SIS18_FAST_20210506_ESR_78KR32.C1 E143 52Mn-2
2021-05-09_19-43-28_ESR_EXP21_06_ISO_78Kr_05May21.C1.txt:# Context: ESR_EXP21_06_ISO_78Kr_05May21.C1 E143 70Se
2021-05-09_19-43-45_SIS18_FAST_20210506_ESR_78KR32.C1.txt:# Context: SIS18_FAST_20210506_ESR_78KR32.C1 E143 70Se
2021-05-09_22-23-23_ESR_EXP21_06_ISO_78Kr_05May21.C1.txt:# Context: ESR_EXP21_06_ISO_78Kr_05May21.C1 E143 72Ge
2021-05-09_22-23-37_SIS18_FAST_20210506_ESR_78KR32.C1.txt:# Context: SIS18_FAST_20210506_ESR_78KR32.C1 E143 72Ge

Beam gone ~0:34.
Working on getting it back.
Back in business ~0:57.

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

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).

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.