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

The source moved during the calibration, measurement stopped at half time.

Detector: 145
Source: B133 high rate
Distance: 305mm
Start time: 14:54:47 15.03.2020
Stop time:  15:06:53 15.03.2020

file name: run034_xxxx.lmd
avrg. rate: 1kHz
dead-time:  11%

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%

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

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)

I introduced a downscaling by a factor of 2^5=32 for the BaF2 during target OFF.
The reason is, that we get a lot reasonable x-ray counts (K-alpha, K-REC) outside target ON phase.
So i want to minimize our deadtime during target OFF, to be able to use the data efficiently if needed.
BaF2 is not really needed in target OFF.

We found that Xray2 and Xray3 the cabling is not consistent:

90 degree detector 
> E_Xray2 for energy
> t_Xray3 for times

145 degree detector
> E_Xray3 for energy
> t_Xray2 for timing

35 degree detector
> E_Xray1
> t_Xray1

We can run like this, but should be aware of it!

-- E calibration seems to have changed! ---

This calibration is based on the source data taken before the experiment:

Xray1: E [keV] = ch*0.01582-1.963
Xray2: E [keV] = ch*0.01799-1.803
Xray3: E [keV] = ch*0.01941-2.618

BaF2 detectors are deactivated nor for the following runs.

in run 66 or 67 we had a single ESR cycle for which the target didn't switch off for new injection and deceleration etc.
Very likely the DAQ also didn't get an OFF signal and collected OFF data to the TRIGGER=1 (ON data) branch.
As a consequence we collected about ~100 counts on the Si in one shot, which was about ~20 counts before this shot.

attached:
1.picture of the target density and beam current at this time.

After run 67 and before run 68, the BaF detectors have been removed in order to reduce the Compton background in the x-ray detectors.

The attached spectrum is for the 90 degree X-ray detector taken for about 3 hours with 118Te52+.
We see two peaks at ~29 keV (K-alpha) and 44 keV (K-REC).

The resolution is about 1.5 keV, and the signal-to-background ratio is also really bad.

The increase of background events at higher E might be induced by Compton scattering of a high E gamma ray from the BaF detectors, which are active and sit close by (not anymore).

With scraper, we have roughly 150-200 (p,g) counts now.

X-rays look fine!

Without scraper, we have very few (p,g) counts, hard to get numbers quickly, maybe ~50.

X-rays look fine!

This is the documentation of the source tests with the 2nd micron DSSSD of 2nd generation (label 3288-17, thickness 529um)

The detector is put into vacuum (~5e-6 mbar) in our test chamber. The source is positioned a few cm above (see fotos).
The Bayard-Alpert Sensor in the chamber has to be deactivated, otherwise the light emission will increase the noise on the DSSSD strongly and reduce its performance.

Additionally the current and voltage from the CAEN HV is monitored with the vulom scalers: ch.13(Icool) = current; ch.14(Ucool) = voltage. 


Source: mixes alpha [239Pu, 241Am, 244Cm]

File directory: lxg1275:/data.local3/test_data_2020/
QuickTest files: si2_test_mixed_source[X].root
lmd files:  Si2_run[XXX].lmd

DAQ Settings:
MADC gate   : 0 delay, 5000ns width
MSCF shaping: 2 us 
trlo config : e127.trlo (trigger=1/tpat=1 for Si, trigger=11 for vulom_scaler)


LMD runs:
-----------------------------
Si2_run001.lmd
Start: Fri 23.10.2020 16:19
Stop:  Mon 26.10.2020  8:36

File-Size: 20GB
Events:   ~53M
comment: 
source roughly centered
CAEN HV scalers not connected

-----------------------------
Si2_run002.lmd
Start: Tue 27.10.2020 16:01
Stop:  Wed 28.10.2020 13:26

File-Size: 12GB
Events:   ~32M
comment: 
source in one corner (x1, y1, see foto)
scalers should be connected now
current monitor range set to LOW
@start det_current=140nA det_voltage=90V
@end det_current=143nA det_voltage=90V

-----------------------------
Si2_run003.lmd
Start: Wed 28.10.2020 13:30
Stop:  Wed 28.10.2020 13:31

File-Size: 
Events:   
comment: 
ramping of det. voltage for scaler/U-F-Converter test
source in one corner (see foto)
scalers should be connected now
current monitor range set to LOW
@start det_current=140nA det_voltage=90V

-----------------------------
Si2_run004.lmd
Start: Tue 24.11.2020 12:50
Stop:  Tue 24.11.2020 

File-Size: 
Events:   
comment: 
source in one corner (x16, y16, see foto)
@start det_current=138nA det_voltage=90V
@end det_current=nA det_voltage=90V

-----------------------------
Si2_run005.lmd
Start: Tue 24.11.2020 14:57
Stop:  Tue 24.11.2020 15:11

File-Size: 
Events:   
comment: 
source in one corner (x1, y16, see foto)
@start det_current=144nA det_voltage=90V
@end det_current=nA det_voltage=90V

-----------------------------
Si2_run006.lmd
Start: Tue 24.11.2020 15:24
Stop:  Tue 24.11.2020 

File-Size: 
Events:   
comment: 
source in one corner (x1, y16, see foto)
Si_X & Si_Y cabling to MADC_0 and TDC_0 exchanged to get right order of channels/orientation
@start det_current=144nA det_voltage=90V
@end det_current=nA det_voltage=90V

Here is the analysis of the test runs with the 2nd DSSD (gen2) using the quick_si_plots.c script attached.

All 32 Si channels are working with acceptable performance. 

In run001, there are some additional low energy peaks in nearly all x-strips, which I do not understand yet. They are around 3 MeV and are not visible in the y-strips. It doesn't look like an electronic problem, because there are at least 4 
peaks, so not a low amplitude copy of the 3 major alpha peaks between 5 - 5.8 MeV.

However, in run002, the peaks have mostly disappeared, only in x6,x7,x8,x9 is a broad structure at somewhat similar energy... maybe this has to do with the small incident angle of the alphas?

Another run to confirm and double check this would be nice.