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Entry  Thu Oct 13 23:42:27 2016, JL Tain et al, Background Bckg-161014.pdf
Background measurement overnight

Start: 01:17
Stop: 10:35
File: 161014_1035_bck.root

See figure
Entry  Thu Oct 13 23:41:25 2016, JL Tain et al, 252Cf 252Cf-161014.pdf
New BRIKEN energy calibration


We check the 3He tubes energy calibration with 252Cf source
We Found that only one tube He006 was slightly shifted and correct it.

Check measurement:
File: 161014_0113_252Cf.root

See figure
Entry  Thu Oct 13 23:39:58 2016, JL Tain et al, VETO Det Plast-Cs.pdfNaI-Cs.pdfPlast-Co.pdfNaI-Co.pdfVETO-testarrangement.jpg
Energy calibration of plastic and NaI detectors


137Cs source placed in the center of the arrangement:
two plastics on top of each other the four NaI
on the sides. See photo.

First measurement:
File: 161014_0015_137Cs_VetoDetCal.root

after calibration check measurement: 
File: 161014_0038_137Cs_VetoDet.root

60Co source: 161014_0047_60Co_VetoDet.root

See figures

ADC ranges at the moment:
Plast: 20 MeV
NaI: 20 MeV
Entry  Thu Oct 13 23:38:26 2016, JL Tain et al, CLOVER D4All-CsCo.pdfD4All-CsCo-zoom.pdfD4Sum-152Eu.pdf
Energy and efficiency calibration

We make calibrations for the remaining D4 CLOVER detector
(No pulser: D4 preamp does not see the pulser input, a single TEST input)

Sources on the cardboard holder, place at the center of BRIKEN



137Cs (Ref:CD393) together with 60Co (Ref:CD395):

File: 161013_2331_137Cs60Co.root



152Eu (Ref:272/09-7011):

File: 161013_2350_152Eu.root



The threshold in Black,Green and Blue is cutting Ba X-rays.

Activity of the sources:
>> 60Co (Ref:CD395): 338.4 kBq (+-3%) measured on 01.07.1990
>> 137Cs (Ref:CD393): 347.9 kBq (+-3%) measured on 01.07.1990
>> 152Eu (Ref:272/09-7011): 10.62 kBq (+-1,9%) measured on 16.03.2010

See figures.
Entry  Thu Oct 13 12:58:31 2016, JL Tain et al, INCIDENT 
NIM Crate Failure. Lost of CLOVER G7

One of the 2 NIM crates, the one containing the power for CLOVER
preamps went kaputt.
As a consequence the preamp of CLOVER detector G7 was damaged:
G7 was removed
Entry  Thu Oct 13 04:36:58 2016, JL Tain et al, CLOVER 161013_1518_137Cs60Co.root
CLOVER energy calibration

Short run with 137Cs and 60Co sources at BRIKEN detector center
to make a new energy calibration

Root file: 161013_1240_137Cs60Co.root

We conected the test input to the pulser, and a new calibration was needed

Root file: 161013_1518_137Cs60Co.root
Entry  Wed Oct 12 11:30:53 2016, Ariel Tarifeno, Alvaro Toloza, JL Tain, J. Agramunt, et al, BRIKEN Z scan 
Scanning of the BRIKEN detector with the 252Cf source 
along the longitudinal axis (Z axis)

Measurements from Z: -42.5cm to 42.5cm with steps of 2.5cm. 
Entry  Wed Oct 12 05:06:57 2016, JL Tain et al, Noise He136-nosource.pdfHe136-137Cs.pdf
Gamma source close to ORNL2 tube

In order to investigate the origin of the background
component in ORNL tubes extending up to 200keV
we place a strong 137Cs source (D393) in the hole
of He136 close to the tube.

Control measurement (no source): 161012_1200_bck_control.root
With source: 161012_1229_137CsHe136.root

We observe that the induced signals are in the same energy region
as the 3rd noise component. The increase of the rate of signals
with the source is a factor 60.

See figures.

This hints to the origin of this component as due to an increased sensitivity
to gamma-rays (more  material?) or internal radioactivity (gamma,beta) 
of ORNL tubes.
Entry  Wed Oct 12 03:47:14 2016, JL Tain et al, Background 
Background measurement over night with CLOVER and VETO detectors

ADC #7 added to crate 1 for veto detectors: V1A7
VETO detectors HV off!

Start: 23:45
Stop: 10:56
File: 161012_1056_bck_noise.root

We see a very strong noise in the BRIKEN spectrum!!!
After some work we find that this was a problem
with configuration file: when editing the file
we put the calibration sheet at the beginning this
provoked a mixing of CLOVER and 3He spectra.
Entry  Tue Oct 11 17:11:28 2016, A. Tarifeno-Saldivia et al..., ROOT macro  BRIKEN_rates_v3.cc
ROOT macro for calculation of neutron rates in the BRIKEN detector

Here a ROOT macro to calculate neutron rates from onlines root files generated DAQ configuration 
160718Conf_BrikenFull_cal5.xlsx (and the later ones).

Setup parameters are indicated at the begining of the macro. An output data file is generated with the rates by counter, ring and ADC. If the input root file is "file.root", the 
output data file is "file.root_data".

Further questions by email to: atarisal@gmail.com


 
Entry  Tue Oct 11 15:58:01 2016, JL Tain et al, VETO Det IMG_20161012_124010.jpgPlastic-137Cs.pdfNaI-137Cs.pdf
Check of Plastic and NaI veto detectors and DACQ settings


Plastic: 10x200x450mm**3, PMT: H1161, HV: -1200V, Anode2
Very small and short signal: width: 20ns, rise: 10ns, amplitude up to 10mV
We decided to put an amplifier to have more flexibility
Amp: Ortec 474 TFA, G: 10xmax, INT=200ns, DIF: 100ns
Signal: width: 200ns, height: 100mV
DACQ Trigger & EFIR: P=2, G:2

NaI: 2"x4"x16", PMT: ?, VD: 1410 (ORNL), HV: +800V
Signal: width: 400ns height: 15mV
DACQ trigger and EFIR: P=20, G=20

File: 161011_2330_PlasticNaI_137Cs.root
File: 161011_2335_PlasticNaI_60Co.root

Photo of the arrangement.
137Cs spectrum of both detectors.
Entry  Tue Oct 11 15:47:45 2016, N Brewer, S Go et al, CLOVER IMG_20161011_182318.jpgIMG_20161011_182258.jpgD4-1st.pdfG7-1st.pdf
Both COVER detectors are installed in place.
See photos.

Detector D4: left of the beam
Crystal distribution:
BLUE-BLACK
RED -GREEN

Detector G7: right of the beam
Crystal distribution:
BLUE-BLACK
RED -GREEN

Cables connected. Some work on noise minimization.
Resolution improved for D4-Black which was poor 
on July. Otherwise similar behaviour.

See spectra with 137Cs and 60Co sources ta the center.
File:161011_1805_CLOVER_CsCo.root
We are using the calibration from July which
works surprisingly well for all except G7Red
(explains double peak in spectrum)

More checks to be done.
Entry  Sun Oct 9 18:19:01 2016, JL Tain et al, Noise 161007_1045_bck_lin.pdf161010_0712_bck_newthr.pdf
Optimization of ADC thresholds

In order to try to reduce the grass-like background
we make a finer adjustment of individual ADC thresholds.
We make first a control measurement putting the 252Cf source
in the center of the detector (AIDA removed)
Start: -
Stop: 23:55
File: 161009_2355_252Cf_control.root

We then make an adjustment of thresholds one ADC at a time.
We adjusted the threshold so that the very low amplitude noise height
in the spectrum is only a small fraction of the pulser.

New configuration file: 160718Conf_BrikenFull_test02_thr.xlsx

A verification measurement with 252Cf
Start: 01:55
Stop: 02:09
File: 161010_0209_252Cf_newthr.root


And the leave a background measurement overnight:
Start: 02:12
Stop: 07:12
File: 161010_0712_bck_newthr.root

We compare the grass-noise rates now with the rates before threshold adjustment
For that we integrate the BRIKEN spectrum between 900keV and 1.5MeV
The rate before was 0.085 counts per second per MeV
The rate now is 0.039 counts per second per MeV
So the improvement was only a factor 2.

One can try to set the thresholds higher  however with this rate the probability
of having a noise signal in a 0.5ms window after a beta signal will be about 1E-5.

The plots below show the situation before and after.
Entry  Sun Oct 9 15:49:41 2016, JL Tain et al, Power shutdown 
Due to maintenance operations of the Wako electrical
company there is a risk of power shutdowns on Saturday,
Sunday and Monday from about 8 am to 8 pm.

So we have to stop working on the hardware during
this time
Entry  Sun Oct 9 04:20:47 2016, JL Tain et al, Noise noHV.pdf161008_0642_noHV.pdf
We check for the appearance of spurious signals in the preamplifiers.

We set all HV to zero and run a measurement for several hours.
Start: October 7, 20:00
Stop: October 8, 06:42
File: 161008_0642_noHV.root

De inspection of the different channels do not reveal any
particular problem.

See figure for channels grouped in rings
Entry  Sat Oct 8 01:18:51 2016, JL Tain et al, DACQ 
We increased the pretrigger delay for ADC5 from 350 to 400
Entry  Fri Oct 7 10:42:52 2016, JL Tain et al, Noise ORNL-DiffPreamp.pdf
We investigate the effect on the noise in ORNL tubes of using a differential PA.

We connect the tubes in current PA10 (126-140) to one of the new diff PA
and connect the output to converter card #4 which is connected to ADC3 (and ADC4).

First a short run with 252Cf for setting the right parameters and the calibration
file: 161007_1743_252Cf_ORNL_diffPreamp.root

Then we make a background run
file: 161007_1743_bck_ORNL_diffPreamp.root

As can be seen in the figure the effect of the differential preamp is to
compress the noise down to 100keV, becoming more similar to
the situation of the RIKEN tubes.

Thus it will be beneficial to use Diff PA. However as we can only setup one
because we have only one spare Diff-Unip converter card, we decided not to
use it as the impact will be very low and implies a lot of changes.
However one must remember that since we are always going to require coincidence
with betas during the measurement this noise should have no effet.
Entry  Fri Oct 7 08:35:15 2016, JL Tain et al, Noise noiseDifferentTubes2.pdf
Low amplitude noise component.

The figure shows the composition of the low amplitude noise
which depends on the tube and type of preamplifier used.

Bkack: He020 (RIKEN-Diff)
Red: He044 (UPC-Diff)
Green: He057 (UPC-Unip)
Blue: He068 (ORNL1-Unip)
Pink: He132 (ORNL2-Unip) 

(all the tubes of the same type and preamp type behave alike)

We can see up to three different structures.
The noise in the ORNL tubes extends to higher energies (200keV)
and are the cause for the overlap of noise with neutron signals,
but other wise the shape is similar to RIKEN tubes.
The noise for UPC above 50kev is quite small.
One can also see a small difference between differential and unipolar PA
in the case of UPC tubes (red and green)
Entry  Fri Oct 7 08:09:47 2016, JLTain et al, Background Bckg-1st.pdf161007_1045_bck.pdf
Background measurement overnight
Start: Oct-6 2242 Stop: Oct-7 10:45

file: 161007_1045_bck.root

See attached figure.
We see that low amplitude noise overlaps with the neutron spectrum.
We also see the grass-like background which extends all the way
up to the ADC range.
Entry  Thu Oct 6 14:50:30 2016, JL Tain, A Tolosa, A Tarifeno,..., 252Cf 252Cf-1st.pdf161006_2235_252Cf.pdf
First measurement with 252Cf source to check the calibration.
AIDA was in place so the source was at the right height
but displaced about 10cm from the center.

We use the last configuation file used in July: 
160718Conf_BrikenFull_cal5.xlsx

tmeas=25min
file: 161006_2235_252Cf.root

The noise is rather small.
The calibration of July is nearly OK!
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