turn down the hv and pull out the detector.  

suggest by 
Hi everybody,

is there now much more rate on  the detectors?

Perhaps it helps to turn down the bias for a while and to take the detectors out of the beam, by pulling the pocket out?

And then see if the leakage current comes down again.
good luck, Thomas

***********************************************
Dr. Thomas Faestermann  |  Tel:  +49-89-2723868
Physik Department E12   |
Techn. Univ. Muenchen   |  Mob:  +49-1626193388

The limit of the leakage current for all Si pads was increased from 1500 nA to 5000nA and 
leakage current was recorded for different Bias Voltages (32V, 35V, 40V, 45V, 50V, 55V 
and 60V).
Since, I_leakage remains < 3 uA for 60 V, it is decided to increase the Bias Voltage for 
all the Si-pads from 32 V to 60 V.
For DSSD and CsI, bias voltages remains same (-50V and -160V respectively).

The detector cable was disconnected . We entered and reconnected the cable.

Attached is a list of all set values for the 5 MSCF shaper modules.
This was done prior to run0251, which served as a final benchmark for those settings.
See: https://elog.gsi.de/esr/E121/62
And https://elog.gsi.de/esr/E121/104

The det. to MSCF assignment is the following:
MSCF 1: Si-pad 1 + 2 p-side/strips (ch. 1-7 + ch. 9-15)
MSCF 2: Si-pad 3 + 4 p-side/strips (ch. 1-7 + ch. 9-15)
MSCF 3: Si-pad 5     p-side/strips (ch. 1-7)
MSCF 4: Si-pad 6     p-side/strips (ch. 1-7)
MSCF 5: DSSD (ch. 1 - 4); CsI (ch. 7 & 8); Si-pad n-sides (ch. 11 - 16)

Note that only the pre-amplification stage of the MSI-8 amplifiers were used for all channels.

attached is a document showing fotos of all involved amplifiers in the chain to document the manual settings active during the experiment.

Summary:
Si-pad n-sides [MSI-8 (1)] were set to 5 GeV      (expected E-deposition ~2 GeV)
Si-pad p-sides [MPR-32 (1 & 2)] were set to 1 GeV (expected E-deposition ~2 GeV)
DSSD channels  [MSI-8 (2)] were set to 5 GeV      (expected E-deposition ~1.2 GeV)
CsI channels   [MSI-8 (2)] were set to 4 GeV      (expected E-deposition  46 GeV)

It seems we got clipped signals from the Si-pad p-sides, because the MPR-32 were saturated due to a wrong gain setting. 
This might explain, why there was not real influence on the spectra when adjusting MSCF settings for those channels.
 
I cannot comment on the CsI gain setting, because i don't know whether the given GeV-range by MesyTec directly applies for CsI & photodiode.

However, for DSSD and Si-pad n-sides the settings look okay.

litv-exp@lxg___: E121_unpacker /path/to/file.lmd --ntuple=RAW,/path/to/new_file.root

1. slow control:
1.1. program file:
litv-exp@ringpi:~/epics/mrcc_ioc/db $ 
1.2 user interface:
litv-exp@lxg1298:~/E121/scripts/GUIe121_new

2. mbs:
2.1 user interface
litv-exp@lxg1298:~/E121/scripts$ ./e121_gui.py
2.2 source 
R4L-47 litv-exp > pwd                                                                                                                                                                                                                        
/esr/usr/litv-exp/2020_e121/                                                                                                                                                                                             
3. go4:
litv-exp@lxg1298:~/2019Munich-Det/Go4-Muenchen-3V785AH-1V830-simple$ go4
4. experimenal data:
litv-exp@lxg1298:/data.local1/E121

How to change scaling factor?
The parameters is in f_user.c file:
1. open the f_user.C with emacs :
R4L-47 litv-exp > emacs -nw f_user.c
2. change the parameters "MWPC_downscale". 
#define MWPC_downscale 0    // reduction = 2**MWPC_downscale                  
3.compile the program.
4. restart mbs.                                                                                                                                                               

Since last night, the signals from the p-side of all the Si pads were seen as negative on picoscope.
The signals from DSSSD, all n-sides of Si pads and CsI were positive which all are in MSCF-5.
Thus, I and RuiJiu, changed the polarity jumpers of MSCF 1,2,3 and 4(all the four jumpers inside the mentioned MSCF) and now hope to see positive signals from the p-side of all the Si pads.

go4 crush up. 
the problem is 
due to  mbs. 
restart mbs. 
see an error. 
restart again. 
the mbs and go4 
are working 
working. 

IQ_2020-03-29_13-05-
56
SC_2020-03-29_13-05-
56

1. stop run0272.lmd.
2. stop NTCAP. 
  NTCAp file:
  SC_2020-03-30_09-28-14
  IQ_2020-03-30_09-28-14
  (saved in drive: p)

We identified an issue with randomly missing adc channels in all lmd-files before run 0273.
This led to errors in the unpacking process. 

This issue is solved with the new config and mapping for the unpacker. 
The respective files are attached here. 
The unpacker is ready to use in /u/litv-exp/unpacker/unpackexps/E121

The adc issue is also understood. We deactivated the internal adc thresholds during the experiment, because we encountered the very same unpacker errors. This solved the problem for all later runs, but we forgot to think about a solution for the earlier runs. 
Mea culpa.

Jan 

Attached is the f_user.c and the mbslog.l files.
The readout function is for the following setup:
3x ADC CAEN V785 
1x SCA CAEN V830
1x TDC CAEN V1190
1x Vulom TRB5 (triggerbox)
1x Vulom4b PEV (priority encoder)
1x TRIVA7
1x RIO4 R4L-47