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  proton-capture on 118Te, Page 15 of 29  Not logged in ELOG logo
ID Date Authordown Category Subject Year
  55   Sun Mar 15 19:46:34 2020 LaszloCalibrationrun042 - Xray35 calib Ba133 - high rate 
Detector: 35
Source: Ba133, strong source
Distance: 334mm
Start time: 19:46:54 15.03.2020
Stop time:  20:20:14 15.03.2020

file name: run042_xxxx.lmd
avrg. rate: 60Hz
dead-time:  1%
  56   Sun Mar 15 20:26:08 2020 LaszloCalibrationrun043 - Xray35 calib Am241 
Detector: 35
Source: Am241
Distance: 334mm
Start time: 20:25:48 15.03.2020
Stop time:  20:56:56 15.03.2020

file name: run043_xxxx.lmd
avrg. rate: 20Hz
dead-time:  ~0%


--------------------

update at 05.05.2020: the cables were probably twisted between the 90 and the 145 angle detectors.
  58   Sun Mar 15 21:01:23 2020 LaszloCalibrationrun044 - Xray35 calib Ba133 - a night long run  
Detector: 35
Source: Ba133
Distance: 334mm
Start time: 21:01:26 15.03.2020
Stop time:  7:11:07 16.03.2020

file name: run044_xxxx.lmd
avrg. rate: 60Hz
dead-time:  1-2%


--------------------

update at 05.04.2020: the cables were probably twisted between the 90 and the 145 angle detectors. However, the id of the detector doesnt change, since there were no simultanious measurements (one source used with one detector a detector at a time)
  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). 
  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))
  118   Sat Mar 21 11:25:47 2020 Laszlo possible misalignement between target and fragment beam 
after 9hours of measurement we see only 19 counts on our targetON silicon detector histo. this low count rate can indicate two scenarios:
-we have a mismatch between the beam and the target (not much if any overlap)
-mabye the very low intersity of the beam (we cannot really monitor this, there are only estimates...)

Which tells us that we dont intersect with the target, that on the Xray spectras we dont see any peaks at 90 and 145 angles. There are two peaks in 35 angle, but they are maybe only from Pb conversion 75keV, etc...
  119   Sat Mar 21 11:30:04 2020 LaszloGeneralMWPC movement 
now we try to move the capture detector (MWPC in the 1. dipol before our Si setup) inside the ring while the DAQ was ON

we tried to move it as close as possible to the beam

On the picture below you can see that we had some increased current while moving the MWPC --> scattering from the beam while scraping it
  123   Sat Mar 21 12:06:50 2020 LaszloGeneralrun61 - SCRAPER moved out 
we want to see any change on the Silicon count rate, because we will have now also Rutherford scattering. 
  125   Sat Mar 21 12:32:00 2020 LaszloGeneralEstimated target thickness 
Target thickness must be like 5mm (was measured with a moving thin wire)
The beam thickness is small because of the low intensity
Maybe we hit the target a bit offset --> less rate?

We might have the option to increase the target 1magnitude more, but this might not help because we can kill the beam 
with this.

I have the impression we just simply have less number of stored ions like 10^4 or evem less...

Yury: "we are unsure about the settings and desperately seek for any means of additional diagnostics"
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