19/Jul/2016
Scanning of the efficiency as a function of longitudinal position

File:160719_BRIKEN_252Cf_XXmm_*.dlt
Online:160719_BRIKEN_252Cf_XXmm.root
Run: 011-025
Distances: -275,-175,-125,-75,-50.-25,+25,+50,+75,+125,+175,+225,+275,+375mm

Measurement with the source at the center

Listmode: 160719_BRIKEN_252Cf_009.dlt
Online: 160719_BRIKEN_252Cf.root

BRIKEN: 1.03697E7
Pulser: 5985

Rate: 17326 n/s

18/07/2016 
First background measurement overnight.


START: 23:37
File: 160718_FullBrikenFirstData_bkg_*.dlt Run:003-006
Online: 160718_FullBrikenFirstData_bkg.root

Attached screenshots of raw data for every digitizer. 

The problem of some of the PA is visible in the background
spectra. 

In addition one can see in some of the channels signals
distributed over all the region up to the pulser and beyond.
This we found to be related to a too low threshold
but can be eliminated with a better adjustment.

First measurement with full 140 tube version 
of the BRIKEN neutron detector

Directory: /data/160716Test01/
Configuration: 160718Conf_BrikenFull.xlsx
File: 160718_FullBrikenFirstData_252Cf_002.dlt
Online: 160718_FullBrikenFirstData_252Cf.root

All tubes and channels working!

Sample of screenshots included.

Pulser settings

We use two pulsers, Pulser1 for RIKEN, ORNL1 and ORNL2 tubes (7 PA)
and Pulser2 for UPC tubes due to the different gains (3 PA)

10HzClock->G&DG->Pulser->LinearFI/FO

Pulser1: BNC BH-1: trise=1us, tfall=1ms, amp=670mV(scope), NEG
Pulser2: BNC PB-5: tfall=1ms, amp=0.180mV(setting), 90mV(scope), NEG 

Later on we found out that Pulser1 is compatible also for 
the CLOVER detectors (8PA). This will require an additional LinearFI/FO

Distribution of connections of tubes in preamplifiers and digitizers



Because of the need to use 10 PAs instead of 9 PAs we had to redistribute
the signal connections. Now: 
PA1(RIKEN), PA2(RIKEN), PA3(UPC), PA4(UPC), PA5(UPC) -> V1A1-V1A4  
PA6(ORNL1) -> V1A5
PA7(ORNL2) -> V1A6
PA8(ORNL2) -> V2A1,V2A2
PA9(ORNL2) -> V2A3,V2A4
PA10(ORNL2) -> V2A5,V2A6

So V1A1 to V1A4 contain now signals from 2 PAs.
We also redistributed the tubes within the PAs
We also changed the numbering or RIKEN Tubes. Tube 1 to 12 are now 
those on the AIDA side (PA1 attached to the PE block)

A figure showing the distribution of tubes an numbering is included.
Tube 1 is behind tube 19 and so forth.

Attached also is an excel file with tube-channel distribution

 We have carried out a scanning of the neutron efficiency with respect to the position along the Z-axis (AIDA and BEAM hole) of a 252Cf neutron source. A preliminary analysis is presented based on data from the online. A plot with the comparison of the simulations and experimental data is attached. The experimental results are in good agreement with the GEANT4 simulations of the studies for design of the neutron detector. The simulations for the design of the hybrid mode were calculated using 148 3He counters. The  version of the hybrid detector assembled during the current campaign (July-2016)  is using 140 3He counters. The missing counters correspond to tubes located on the outer part of PE, thus the effect of these counters on the total neutron efficiency is minimal. 

RIKEN tubes on the AIDA side with the SHV right angle connector will protrude
by ~95mm in the HYBRID configuration (with CLOVERS). 
In the current AIDA DSSD configuration there are six detectors occupying 45-50mm 
at a distance to center of the stack from the black plastic support of ~430mm.
The hole for the CLOVER is 110mm. The center of the hole is at 375mm from the
PE end. 
This means that the center of the current stack is only ~15mm beyond the PE
in the CLOVER hole, so 1 or 2 of the DSSD will be partially shadowed
from the CLOVER detectors. 
(This do not represent any problem from the neutron detector point of view)

Racks, crates, rear part of the preamps and matrix with all tubes.

The photo of great moment

Preamplifier and signal cable testing

We check all signal cables,the flat cable connector to BNC 
from ORNL/UTK and they are OK.

While checking the preamplifiers (PA) we realized that on the oscilloscope
some of the channels shown pulses without a load when HV is on.
After some checks, we come to the conclusion that is a kind of discharge
on the HV part of the preamp (which appears as positive pulse or negative pulses)
and induce pulses of opposite sign in one or mos neighbouring channels.
After systematically investigating them in the scope, we plug them in the DACQ
to record the spectra. For this we include an additional digitizer SIS3316
to connect al1 channel preamps
PA1(D):UPC:SN-0808223 -> V1A1
PA2(D):GSI:SN-1112572 -> V1A2
PA3(D):UPC:SN-0310315 -> V1A3
PA4(D):UPC:SN-0808220 -> V1A4
PA5(U):UTK: ? -> V1A5
PA6(U):UTK:SN-0808218 -> V1A6
PA7(U):UTK:SN-0713586 -> V1A7
PA8(U):UTK:SN-0808221 -> V2A1, V2A2
PA9(U):UTK:SN-0808215 -> V2A3, V2A4
PA10(U):UTK:SN-0808217 -> V2A5, V2A6

We measure first with a tube of each type connected to Ch#1 of each PA
to adjust parameters of digitizers and range
List-mode: 160717_preampCheck_000.dlt
On-line: 160717_preampCheck.root

Then we remove the tube from Ch#1 to see the effect in this channel:
List-mode: 160717_preampCheck_noTubes_001.dlt
On-line: 160717_preampCheck_noTubes.root

We attach screenshots for both as compressed files (.zip)
and the root files

Adjustment of HV and PA gain

We adjust the HV for each tube type and the gain of the preamplifier (PA) in order
to have a similar signal amplitude for the 764keV peak in all of them.
Because of the very different gain between tubes we are not able to combine in the same
PA tubes from RIKEN and UPC, thus we have to go for 10 PA instead of 9:

Settings: Preamp (type), Tube type, HV, Gain, height or 764keV pulse, pulse polarity
PA1 (D), RIKEN, 1450V, LowGain, ~400mV, POS
PA2 (D), RIKEN, 1450V, LowGain, ~400mV, POS
PA3 (D), UPC, 1550V, HighGain, ~400mV, POS
PA4 (D), UPC, 1550V, HighGain, ~400mV, POS
PA5 (U), UPC, 1550V, HighGain, ~600mV, NEG
PA6 (U), ORNL1, 1200V, LowGain, ~400mV, NEG
PA7 (U), ORNL2, 1750V, LowGain, ~400mV, NEG
PA8 (U), ORNL2, 1750V, LowGain, ~400mV, NEG
PA9 (U), ORNL2, 1750V, LowGain, ~400mV, NEG
PA10 (U), ORNL2, 1750V, LowGain, ~400mV, NEG
 
We need  to use two different pulse generators to adjust differently the pulse height
of UPC tubes

Test of individual 3He tubes

The tests were done using the ATOMKI MCA and
HV: ISEG NH204M
Preamp: Mesytec MHV-16 (Unipolar IFIC) 
Amp: ORTEC671 (Gain=5x0.5,SHP=6us)
Pulser: 10Hz-Clock + TC410A G&DG + BH-1 (tr=1us,tf=1ms,amp=0.7)
Spectra measured with 1024 channels
Counting time:   100s (UPC, RIKEN and ORNL 1")
                 120s (ORNL 2")
Neutron source:   252Cf
PE setup: 1 inches tubes were tested on the BELEN-20 PE matrix, while for 2 inches tubes a moderator was prepared 
using existing material (see attached figures). 

Attached a figure with a sample spectrum for each tube type
and a  compressed file with all the measured spectra in ASCII format.

All the tubes performed correctly. The neutron signal is well separated from the noise. 
The RIKEN tubes have the highest gain. Gain in the UPC tubes is the lowest.
 

You can start applying HVs on the detectors using macro on the control-computer.

If you have already signed in the computer that controls mpod,

1. Type http://192.168.13.239/  to monitor the status of HV.

2. Go to the directory : /home/pixie16/DAQ_1/include and open the config file : hvmon.conf

Type      IP address          channel      slot  name   voltage   Current   RampUp  RampDn    Switch On/Off/RESET
                                                            V         A       V/s      V/s            1 / 0 / 10
------    ---------------     ---------    -----  ----   -------   -------   ------  ------    -------------
 0        192.168.13.239         0           0     PA1     1450     0.0001       50      10            0
 0        192.168.13.239         1           0     PA2     1450     0.0001       50      10            0
 0        192.168.13.239         2           0     PA3     1550     0.0001       50      10            0
 0        192.168.13.239         3           0     PA4     1550     0.0001       50      10            0
 0        192.168.13.239         4           0     PA5     1550     0.0001       50      10            0
 0        192.168.13.239         5           0     OFF       0      0.0001       50      10            10
 0        192.168.13.239         6           0     OFF       0      0.0001       50      10            10
 0        192.168.13.239         7           0     OFF       0      0.0001       50      10            10
 0        192.168.13.239         0           1     PA6      1200    0.0001       50      10            0
 0        192.168.13.239         1           1     PA7      1750    0.0001       50      10            0
 0        192.168.13.239         2           1     PA8      1750    0.0001       50      10            0
 0        192.168.13.239         3           1     PA9      1750    0.0001       50      10            0
 0        192.168.13.239         4           1     PA10     1750    0.0001       50      10            0
 0        192.168.13.239         5           1     OFF       0      0.0001       50      10            10
 0        192.168.13.239         6           1     OFF       0      0.0001       50      10            10
 0        192.168.13.239         7           1     OFF       0      0.0001       50      10            10
 0        192.168.13.239         0           3     D40      3000    0.0001       2       5             0
 0        192.168.13.239         1           3     D41      3000    0.0001       2       5             0
 0        192.168.13.239         2           3     D42      3000    0.0001       2       5             0
 0        192.168.13.239         3           3     D43      3000    0.0001       2       5             0
 0        192.168.13.239         4           3     G70      2500    0.0001       2       5             0
 0        192.168.13.239         5           3     G71      3000    0.0001       2       5             0
 0        192.168.13.239         6           3     G72      2500    0.0001       2       5             0
 0        192.168.13.239         7           3     G73      2500    0.0001       2       5             0

When you want to start HVs, you may have to change the last bit to be 1.

Then go to the following path /home/pixie16//DAQ_1/hv-mpod and execute the command ./hvmon (The process should start),

When you want to down HVs, you may have to change the last bit to be 1.

Sometime you may get error messages colored red on the status monitor when you down the HVs, then you have to change the config file (hvmon.conf) and set the last bit to be 10 to clear the error messages.

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

The IP adress of the computer is currently 192.168.13.250. The user name : pixie16, password: ask Nathan or Shintaro

For now, slot names PA should be He3 and DXX and GXX should be clovers.

You can also change the HV values by changing hvmon.conf

Today several tests (3) were done with the germanium detectors with the voltage configuration listed in the previous entry.

The tests were as follows:

Tests with 60Co+137Cs sources

1. Initial evaluation of calibration and resolution (Calibration60Co137Cs_energySignal.root)

2. Cable changes to optimize resolution for detector D4 (Calibration60Co137Cs_timingSignal.root)

Test with 152Eu

3. Final (proposed) configuration of filter parameters, voltages, and cable connections. (Calibration152Eu.root)

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

At the time of this log the evaluation of resolution and calibration based on Eu data is to be completed.

The configuration file for the Ge is listed in FirsttestGe.xlsx .

The details of the tests can be found in the attached .pdf pictures or in the .root files.

You may notice that 2/4 of each clover count less than the other 2 and this is due to source position.

For the runs on Co and Cs It was seen that D4 had considerable tailing in channels 1 and 3 (black and green leaves, respectively) and D4 has worse resolution. Channel 3 (green) also requires a non-linear calibration. Currently only linear calibration is applied. But this is as expected from how the detectors were running before leaving Tennessee.

Therefore we decided to check if the second group of signal cables had better resolution for detector D4. The second group of cables were presumed to be timing signals and the run is labeled as such, however, the signals are similar within a few percent and this assumption may have been incorrect.

The result is listed in calibrationClovers.ods  in the third tab (TimingvsEnergy).

!!!Noise in the different groups of cables should be evaluated.!!!

Based on this test the first cable from the first test in D4 was reattached and the others remain in place. The second channel saw improvement and the 3rd and 4th channels saw limited change (deemed insignificant). This bundle has been labeled 'D4 Signal' for now.

Avg. D4 Resolution for Co and Cs lines is 3.3 keV FWHM

Avg. G7 Resolution for Co and Cs lines is 2.6 keV FWHM

We estimate that these are accurate within ~10%. But this is sufficient analysis for this point and time.

Further details will be posted regarding the Eu data , at a glance the configuration is seen to be very close except for the known non-linearity in D4 and one channel from G7 which should definitely be recalibrated. Thresholds and noise levels should also be re-evaluated.

Expected Resolution:

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

G7 should be ~2.0 keV FWHM at 600 keV for all crystals.
D4 should be as low as 1.8 and as high as 3.3 keV FWHM at 600 keV.

Configuration File: (~/DAQ_1/include/hvmon.conf)

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

 Type      IP address    channel  slot  name   voltage   Current   RampUp  RampDn    Switch On/Off
                                                                                     V             uA      V/s     V/s            1/0
  ------    ---------------            ---------    -----    ----      -------     -------   ------  ------    -------------
 0        192.168.13.239         0           3     D40      3000       0.5       2       5             1
 0        192.168.13.239         1           3     D41      3000       0.5       2       5             1
 0        192.168.13.239         2           3     D42      3000       0.5       2       5             1
 0        192.168.13.239         3           3     D43      3000       0.5       2       5             1
 0        192.168.13.239         4           3     G70      2500       0.5       2       5             1
 0        192.168.13.239         5           3     G71      3000       0.5       2       5             1
 0        192.168.13.239         6           3     G72      2500       0.5       2       5             1
 0        192.168.13.239         7           3     G73      2500       0.5       2       5             1
 

In all cases (Temperature Monitor, ACQ, etc.) D4 comes before G7 and in the same order.

Electronics and DACQ for July 2016 assembly: hardware and connections

Tube distribution in the moderator, pre-amplifiers and digitizers

Drawings and specs of 3He tubes

Drawings of the polyethylene neutron moderator and table assembly