measurement with old tennelec specAmps, do not use for efficiency!

Detector: 145
Source: B133 high rate
Distance: 305mm
Start time: 15:10:15 15.03.2020
Stop time:  15:31:16 15.03.2020

file name: run035_xxxx.lmd
avrg. rate: 1kHz
dead-time:  12%

We are now using new SpecAmps for the x-ray detectors from ORTEC, they deliver much improved resolution but have other strange effects as discribed in the next entry.

We found a strange behaviour of our ADC gates for the x-ray detectors.
The setting as shown in the foto below corresponds to a delay of 5 us and a gate length of 15 us.
This is the only setting that produces nice spectra, even though the signals and gate are not aligned.
The setting is extremely sensitive to the delay 4 us still works but 3 or 7 us give already reduced energy values and beyond these values the spectra disapears.

For now it was decided to operate with this not-understood settings because the result is pretty good...
However, further investigation to understand whats happening would be desirable.

Additional note:
This effect appeared after using the new ortec SpecAmps. Before this we used old Tennelec Amps which delivered horrible resolution, but the gates and signals could be matched as expected at this time.

Detector: 90
Source: Am241 
Distance: 200mm
Start time: 17:15:12 15.03.2020
Stop time:  17:32:17 15.03.2020

file name: run036_xxxx.lmd
avrg. rate: 450Hz
dead-time:  5%

Detector: 90
Source: Am241 
Distance: 167.5mm
Start time: 17:40:00 15.03.2020
Stop time:  17:49:57 15.03.2020

file name: run037_xxxx.lmd
avrg. rate: 620Hz
dead-time:  7%

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

update at 05.05.2020: the cables were probably twisted between the 90 and the 145 angle detectors.

Detector: 90
Source: Ba133 - high rate
Distance: 167.5mm
Start time: 17:53:38 15.03.2020
Stop time: 18:05:41 15.03.2020

file name: run038_xxxx.lmd
avrg. rate: 2.6kHz
dead-time:  26%


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

update at 05.05.2020: the cables were probably twisted between the 90 and the 145 angle detectors.

Detector: 90
Source: Ba133
Distance: 167.5mm
Start time: 18:10:02 15.03.2020
Stop time:  18:47:36 15.03.2020

file name: run039_xxxx.lmd
avrg. rate: 150Hz
dead-time:  2%

Detector: 145
Source: Am241
Distance: 305mm
Start time: 18:53:16 15.03.2020
Stop time: 19:18:35 15.03.2020

file name: run040_xxxx.lmd
avrg. rate: 230Hz
dead-time:  3%


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

update at 05.05.2020: the cables were probably twisted between the 90 and the 145 angle detectors.

Detector: 145
Source: Ba133
Distance: 305mm
Start time: 19:22:34 15.03.2020
Stop time: 19:38:44 15.03.2020

file name: run041_xxxx.lmd
avrg. rate: 1kHz
dead-time:  11%


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

update at 05.05.2020: the cables were probably twisted between the 90 and the 145 angle detectors.

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%

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.

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)

Intensities for special gamma or x-ray lines needed for efficiency calibration can be found here:


ENSDF
https://www.nndc.bnl.gov/ensdf/#

NUDAT
https://www.nndc.bnl.gov/nudat2/

An old but still usefull data base:
http://nucleardata.nuclear.lu.se/toi/nucSearch.asp

measured beam diagnosis with 124Xe48+ at 326 MeV/u

beam: 118Te52+
energy: 7.4 MeV/u

purpose: data with TARGET ON

Detector position (Si): xxx mm

run start at 14:21 , first file: run0xx_0001.lmd
run stop  at 17:11 , last file:  run088_0178.lmd

_______________________________________________________________________________

time: 14:45

ON Rates
Si_X:       29 Hz
Si_Y:       31 Hz
Xray_35:   592 Hz
Xray_90:   168 Hz
Xray_145:   xx Hz
BaF_OR:    xx Hz

Si voltage:          x.x V  
Si leakage current:  x.x uA


SIS particles before:           5e9
ESR particles at injection:     1e6
ESR particles after decel.:     1e5
Target ON density:              5.5e13


copy and repeat the above (below the line) every 30 minutes

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

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). 

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)

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.

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)