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  proton-capture on 118Te, Page 16 of 29  Not logged in ELOG logo
ID Date Author Categorydown Subject Year
  Draft   Fri Jun 28 14:06:28 2019 JanGeneralCAD of (p,g) setup 
  23   Wed Sep 25 13:58:24 2019 LaszloGeneralGamow window energies for 118Te(p,g) 
# Z   A   Iso Re Rc   T9 upper width mxpos  shift
 52 118 te118 pg 20  0.5  1.39  0.58  1.06  -0.01
 52 118 te118 pg 20  1.0  2.27  1.04  1.69  -0.01
 52 118 te118 pg 20  1.5  3.04  1.46  2.21  -0.01
 52 118 te118 pg 20  2.0  3.71  1.82  2.68  -0.01
 52 118 te118 pg 20  2.5  4.32  2.16  3.10  -0.02
 52 118 te118 pg 20  3.0  4.85  2.44  3.47  -0.06
 52 118 te118 pg 20  3.5  5.35  2.73  3.79  -0.12
 52 118 te118 pg 20  4.0  5.79  2.97  4.08  -0.19
 52 118 te118 pg 20  5.0  6.55  3.38  4.61  -0.35

source: https://journals.aps.org/prc/supplemental/10.1103/PhysRevC.81.045807
  35   Fri Feb 21 11:29:02 2020 LaszloGeneralShift plan 
https://docs.google.com/spreadsheets/d/14m8WcCq1erx6HqWJRK7TLbCx121IkjqGa5l-frf4YjI/edit#gid=0
  40   Wed Mar 11 14:33:44 2020 LaszloGeneralbeam time manual 
Here you can find the digital version of the E127 beam time manual.
  60   Tue Mar 17 08:15:49 2020 JanGeneralcurrent grids & screen in TE  
measured beam diagnosis with 124Xe48+ at 326 MeV/u
  62   Wed Mar 18 09:53:28 2020 Laszlo, JanGeneralvacuum after opening gate valve 
Gate valve to DSSSD setup was opened on Tue 17.03. ~9:00

The vacuum on Wed 18.03. ~9:00 was
1.6e-10 mbar at DSSSD setup
1.0e-11 mbar at ESR dipole
  63   Thu Mar 19 09:43:28 2020 LaszloGeneralStatus of the ESR 
After two days of tuning the beam, yesterday evening (~8pm), it was found out that within one ESR pattern using the new control system the harmonics of the cavities cannot be changed. This gives us a fatal limitation, that we cannot go lower 
than 10MeV/u with the beam energy.
-As a first attempt we try to reach this 10MeV/u with two steps deceleration (first to 30MeV/u). At this 10MeV/u we have the p,n channel opened as well, which based on TALYS gives significant, weird shaped background in the spot of the p,g 
peak both in xy and xE histos.
-A second option would be that we inject the beam to ESR roughly at 330MeV/u. Then we can decelerate until 5MeV/u, but there is no stochastic, neither e-cooling available. This result to a "hot" decelerated beam with intensity factor 5 less 
(in optimistic scenario). But for this the whole tuning phase (the first two days of the beam time) must be remade, we have to start basically from scratch. 




It is "funny" that we have a very limited 5 days of beam time which is spent estimately >99% with, from the physics point of view, completely useless beam manipulation issues, which in a normal world must be done already in the engineering 
beam time... 
It is quite challenging to stay positive at the current status (not positive in the sense of the growing Corona-virus). 
  64   Thu Mar 19 15:09:29 2020 JanGeneralstarting off with DSSSD 
here is my short guide how to start with the measurement as soon as we have a beam available.

0. ESR timing in DAQ (maybe Uwe can also assist here)
    - when the cycle is running already, even for tuning, you can try to make the cabling for ESR timing (jet ON/OFF)
    - replace the gate generator signals by the ESR timing signals in the Messhütte and check UDP reader (E127_rates)
    - the settings for ESR timing (event & machine) depend on the cycle, talk to Sergey or so, its the same settings as for the target in HKR
    - with the current cycle this would be: ON-{machine 11, event 55}, OFF-{machine 13, event 55}
    - the event for end of this process is alway 55
    - if it works all tpat rates should be switching from upper to lower panel with the ESR cycle in the rate monitor (as they do now with the gate generator)

Once the tuning is finished:

1. optimize target ON/measurement time
    - switch target to event and use the same machines/events as above
    - check number of ions in ESR at ON and OFF and lifetime of beam
    - we should measure for a drop of a factor of 3-4 roughly i would say
    - e.g. start with 2e5 and stop with 5e4
   - if we start with more, we can measure longer

1. without target,  put in Si detector (GE01DD4AS in device controle) to max-in position
    - see if it disturbs the ESR cycle (discuss optimization with ESR guys if necessary)
    - we should also check vacuum in ring (i think this can be done remotely, ask Markus, Sergey or so)

2. make Si settings with beam (call me i can do things remotely)
    - voltage to 60 volts, use E127_epics (i would expect the current at ~1uA, if no light source is close by)
    - check picoscope for signals during entire cycle
    - picoscope: (ch1: E_x ,ch2: Ex, ch4: gate)
    - select central strip in y and 1st or 2nd x-strip as monitor output with epics (E127_epics > MSCF Si 1 & 2)
    - if you don't get any at all, switch on target in measurement cycle (or permantely)
    - still no nice signals? -> polarity is probably wrong, we need to switch MSCF of X and Y
    - during our measurement period, the signals should be well below 10V (goal for reaction ions ~6V)
    - adjust shaping time, gain, pole zero, threshold (epics) and Si-gate delay and length (e127.trlo) until you get nice histos
    - if you see large rates at injection or decelleration, we should try to shield detector with the scraper
    - put it as close as possible without disturbing the cycle, i.e. loosing more beam than without scraper
    - we can also move it by event (e.g. move in or out on start or end of machines 4,6,11,12,13) depending on when it disturbs

3. find beam position at detector
    - stop the cycle in SC 11
    - try to scrape it away by moving the detector our with small steps
    - you will need several injections, because if the short liftime, can get tedious
    - follow instructions and numbers here: https://elog.gsi.de/esr/E127/37

4. last things
    - ignore BaF for now
    - check that x-rays are working, spectra okay? resolution?
    - check rates during ON (x-rays: some 100 Hz each, Si: low, probably below 100Hz) and OFF (below 100Hz for all but BaF)
    - check deadtime, do we need downscaling for any detector? (i would not expect this, BaF is downscaled already, don't worry)

5. first runs
     - measure with and without scraper to confirm that Rutherford is under controle
     - how long? > depends on the statistics
     - try to see a clean effect of scraping, e.g. by the Si-plot E_ion vs x_position (Laszlo)
  65   Thu Mar 19 19:14:40 2020 LaszloGeneralprimary beam measurement 
Now our aim is to decelerate the primary beam (naked 124Xe) down to 10MeV/u. At this energy we can test our detectors and that how the scraping works. In addition, in the E108b experiment, 124Xe(p,g), there is no measurement point at 10MeV/u.
  66   Thu Mar 19 23:48:56 2020 LaszloGeneral124Xe primary beam at 10Mev TargetOFF 
Beam lifetime is estimated to be 11sec at least (hard to.see with the cursor the corrct values on the shottky monitor) 
but Yury says it is even 
~20sec. The particle njmbers are on the attached picture, however at 10Mev the cirrent measurement is not.really 
teustable (too low beam current)
  67   Fri Mar 20 01:11:58 2020 LaszloGeneralTarget - beam jntersection 
We have managed to find the target position with the beam by looking at the xray spectra. The trick was that at 10mev we 
only have a low increase in the xray rates, so.we went for 400Mev/u where the rate change was dramatic (see in the 
picture)
  68   Fri Mar 20 01:21:00 2020 LaszloGeneraltarget is switched on event based 
  70   Fri Mar 20 01:36:48 2020 LaszloGeneral124Xe primary beam at 10Mev TargetON 
We didmt see any effect on the lifetime if the target is switched on. It is because we use only hydrogen target (but why 
is.it so?)
  84   Fri Mar 20 16:48:00 2020 LaszloGeneralflipped Si shaper output in x and y 
Yesterday evening we have found out that the energy signals from the silicon are negative --> wrong polarity of the shapers was chosen while using the jumpers.
Cables coming from the preamp are switched now. --> in the recorded data the X and Y coordinates of the Si strip detector is the other way around!
Hopefully, the left and right side we can judge well...
  89   Fri Mar 20 22:51:36 2020 LaszloGeneralTarget on signal change 
From the previous settings:
JetOn
  mashine number 11
  Event number 55
JetOff
  Machine number 13
  Event number 55

The new settings for our daq:
Jeton
  Machine number 12
  Event nr. 32
Jetoff
  Machine njmber 13
 Event number 55
  90   Fri Mar 20 22:54:30 2020 LaszloGeneralFirst view of the beam 
Intensity from Sis 1.7E9
The intensity is too.low at ESR to be visible. However we could.catch it somehow with Shottky (picture below)
  91   Fri Mar 20 23:43:26 2020 LaszloGeneralVacuum while moving in the detector at yesterday evening 
Vacuum before DSSSD movement: 1.5844E-11
Top value after movement: 3.64378E-11

This oscillating effect is due to magnets?
  92   Sat Mar 21 01:25:07 2020 LaszloGeneralVacuum while moving in the detector for fragment measurement 
Stayed below E-10
Start:2.42E-11
Top after moving: 4.144E-11
  93   Sat Mar 21 01:44:57 2020 LaszloGeneral  
from the SIS side they could optimize the intensity. we gained a factor ~3. Now the SIS intensity is at 
  97   Sat Mar 21 02:36:44 2020 LaszloGeneraldetector and scraper position 
For the 124Xe primary beam measurement:
-with the DSSSD we scraped the beam at position -40
-position of the detector is set to -25. (1.5cm away from the beam)
-with the scraper (at Eggelhof 1 position) we scraped the beam at ~(-15)-(-13)
-position of the scraper is set to +20 (3.5cm away from beam axis (sollbahn))

For the 118Te fragment measurement:
-with the DSSSD we scraped the beam at position -39
-position of the detector is set to -24 (1.5cm away from the beam)
-with the scraper (at Eggelhof 1 position) we scraped the beam at ~ -14
-position of the scraper is set to +19 (3.5cm away from beam axis (sollbahn))
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