Background measurement overnight.

Start: 23:27 (07/11/2016)
Stop: 07:52 (08/11/2016)
ROOT file: 161108_0751_Overnight.root


The spectra have a terrible aspect!

This is consequence of DACQ crashing because LN2 filling!

For second part of Takechi's run:

Directory: /data/1611Commissioning/161107Parasitic
Config File: 161107Conf_BrikenFull.xlsx

Attached is the draft for the paper run sheet (version 2). If something is missing, please let me know.

To have a range of about 200 MeV

Ortec671 Gain from x20 to x5 (fine gain : x0.5)
HV from 1500V to 1300V
60Co-> 10 mV

Root file: 161107_1800_AIDAplasticCalib.root

calibration a1= 0.001 MeV/units

HPGe fill line to D4 replaced only small leak (overflow) once Ge is full.

Solenoid was also wrapped to no effect. AIDA DAQ still stops writing.

Boron sheet and extra polyethylene were placed back on top.

new calibration for F11

Using a value of 70 MeV energy loss and the file 161107_0833_Overnight.root
We obtained new peak positions: for V1A7C3 peak at 5398 (F11 right), for V1A7C4 (F11 left) peak at 6060

F11_rigth (V1A7C3): 0.01297
F11_left (V1A7C4): 0.01155

AIDA plastic (veto) and Si de calibration

For the calibration the Compton edge of the spectrum seen in the detectors was used.
There is a large uncertainty in that determination, since the spectra are not so clear in terms of shape.

For the spectra V1A7C13_EFIR (Si de, top) the channel position is 12900 units

For the spectra V1A7C14_EFIR (Si de, bottom) the channel position is 12950 units

For the spectra V1A7C9_EFIR (AIDA plastic) the channel position is 10425 units

These corresponds to the following calibration factors using 0.9 MeV as the Compton energy from Co source:

V1A7C13_EFIR (Si de, top): 6.976744E-5
V1A7C14_EFIR (Si de, bottom): 6.949807E-5
V1A7C9_EFIR (AIDA plastic): 8.633094E-5

60Co source placed close to the detectors:

ROOT files: 
161107_1221_SiDetCalibration.root
161107_1237_AIDAPlasticCalibration.root

Photo of the white board with the details on the cards and preamps at B1F

First 50,49,48Ca beam and then 47,46,45Ca beam
C-6mm IN and OUT

New Configuration file: 161107Conf_BrikenFull.xlsx

Start: 00:43
Stop: 08:33
Tmeas:12883.1 s


ROOT file: 161107_0833_Overnight.root

There is a change of gain for F11_PL_R and F11_PL_L

Rates:
F11R: 1150 cps / 950 cps
BRIKEN: 70->40 cps / 45->25 cps
VPLT: 34->12 cps / 34->12 cps
VPLB: 6->2 cps / 6->2 cps

Counts:
RateF11R: 1.41342e+07
RateBRIKEN: 697082. (4.9 neutrons/100 particles)
Corr_BR_F11R: 632710 (91%)
Estimated background: 5153.24
RateVPLT: 376233.
Corr_BR_VPLT: 213977 (315)

CH2 target at F7 in
Start with Empty at F11
Change to C-6mm at F11 later

Start: 16:16
Stop: 17:25

Change to C-6mm at 16:47 (at 544E6 ms in Timestamp units)

ROOT file: 161106_1725_58Ni_F7CH2.root

Rates:
F11R: 2000 cps
BRIKEN: 20 cps -> 35 cps
VPLT: 16 cps -> 40 cps
VPLB: 1.5 cps -> 5.5 cps

Figures Rate BRIKEN (red) Rate V_PL_T (blue)

Counts:
RateF11R: 8006721

RateBRIKEN: 111089 (1.4 neutron/100 particles)

Corr_BR_F11R: 108817 (98%)

RateBRVPLT: 115440

Corr_BR_VPLT: 21486 (19%)

RateBRVPLB: 16109

58Ni in F11 C-6mm (later empty)
F7 CH2 target out (F5 CH2 target in)
Thresholds in V_PL_* lowered from 20MeV to 1MeV

Start: 15:37
Stop: 1609

ROOT file: 

They put the empty position of the F11 target ladder 
at 15:48. 
BRIKEN neutron count rate was reduced by a factor 2!
Also veto plastic det.
 
Rates:
F3: 4000 cps
F11_PL_R: 1350 cps
BRIKEN: 23 cps -> 14 cps
VPLT: 28 cps -> 12 cps
VPLB: 4 cps -> 1 cps

ROOT File: 161106_1609_58Ni_F11_empty.root

Figures Rate BRIKEN (red) Rate V_PL_T (blue)

Counts:
RateF11R: 2512767

RateBRIKEN: 30363 (1.2 neutron/100 particles)

Corr_BR_F11R: 29176 (96%)

RateBRVPLT: 31275

Corr_BR_VPLT: 5424 (17%)

RateBRVPLB: 3764

New calibration in V_PL_T and V_PL_R (Energyx1/2)

Start: 15:15
Stop: 15:35

File: 161106_1535_58Ni_F11_C6mm.root

Rates
F11_PL_R: 1300 cps
BRIKEN: 22 cps
V_PL_T: 7 cps
V_PL_B: 0.3 cps

Measurement during beam production
and measurement with F7 CH2 out, 
F11 C-tar in/out, F7 CH2 in C-target out/in

START: 02:45
STOP: 12:47

ROOT file: 161106_1247_Overnight.root

62Ni beam in F7 ON CH2 target

Strat with C target ladder in F11 in empty position.
They changed to C 6mm after a while (5-10min) but we 
didnt realized that!

THERE ARE NO APPRECIABLE DIFFERENCES WITH THE C-TARGET IN OR OUT!

DLT: 161106_0210_62Ni_F7_empty_002.dlt
Start: 02:10
Stop: 02:32
tlife: 1292.80 s

ROOT file: 161106_0232_62Ni_F7_empty.root

Rates at 2:19
F3: 2800 cps
F11: 1200 cps
BRIKE: 32 cps
VPLT: 17 cps
VPLR: 1 cps

Counts:
RateBRIKEN: 47703 (36.9 cps)

RateF11R: 1688270 (1305.90 cps)

Corr_BR_F11R: 47603 
(all neutrons are correlated with a particle going through F11)

RateBRVPLT: 23826 (18.43 cps)
Corr_BR_VPLT: 7557 
(15.8% of the neutrons are correlated with a particle 
going through plastic veto top) 

RateBRVPLB: 1865 (1.44 cps)
(the rate is 12.8 times smaller than top detector)

Empty position of the target ladder at F11
(hole is smaller than beam size)

CH2 target at F7 is OUT

DLT 161106_0126_62Ni_F11_empty_001

Start: 01:26
Stop: 01:40

NO ROOT FILE!!

At 01:32:
Rate at F3: 2600 cps
Rate at F11: 850 cps
Rate at BRIKEN: 13 n/s
Rate at VPLT: 3 cps
Rate at VPLB: 0.1 cps

62Ni on 6 mm C target between MUSICs

The background before was 0.36 neutrons/s
Now it is around 10 n/s
With 3100 counts/s at F3 we have of the order of 25 neutrons/s
There is an slightly higher than 10 factor between the rate of 
the plastic top and bottom (13 cts/s vs 1ct/s).
Rate at F11 (plastic) 900 cts/s.

We start a proper measurement with DLT
Reset Timestamp

They will measure with 6mm C target (between MUSICS) for 
about 45 minutes and then 15 min without target.
CH2 target at F7 is OUT (beam going directly to F11).

DLT: 161106_0026_62Ni_F11_C6mm_000
Run: 000

Start: 00:27
Stop: 01:17
tlife=3007 s

At 00:37
Rate at F3: 3000 cps
Rate at F11: 900 cps
Rate at BRIKEN: 25 n/s
Rate at VPLT:13 cps
Rate at VPLB: 0.8 cps

Root File: 161106_0117_62Ni_F11_C6mm.root


Figure with rates: F11 (black), BRIKEN (red), Clovers (green)
V_PL_T (blue), V_PL_B (pink)

Figure with F11 spectra: Right (red), Left (blue)

Figure with time correlation between F11 and BRIKEN
The number of correlations (integrated spectrum minus flat background)
is 73063 very close the number of detected neutrons 73899
The difference 833 agrees well with the expected number of background
neutrons. That is: for every neutron detected in BRIKEN there was an 
ion passing through F11 (!?).
There is a funny double structure in the first 20 microsec.
94% of the neutrons are detected within 200microsec

Figure with the spectra of Veto plastics Top (red) and
bottom (blue). There are 7.5 times more counts in T than in B.
One can see in the Top peaks at 3MeV and 12MeV 
(corrected from 6 and 25 MeV: wrong calibration!!)
and show signals up to very high energy (GeV)

Figure with the time correlation between Veto Plastics and BRIKEN
Top (red) Bottom (blue). There is a time correlation with Top veto plastic
for 15% of the neutrons in BRIKEN (11440). There  are 18 times less 
correlations with the Bottom plastic. 
WARNING: The correlation was done for signals above "20MeV"
in the V_PL_T spectra i.e. only including the second bump"

Some info on ancillary detector signals

Plastic veto detectors (Top and Botomm):
The dynode signal of the PMT is passed through an
ORTEC 474 TFA amplifier before going to the DACQ
TFA: Gain=6 x min(~x2), Tint=200ns,Tdif=100ns, NonInvert
DACQ channels: Top: V1A7C1, Bottom: V1A7C2
Photo of the signals of both detectors attached 
with 60Co source (with gain changed to 20 x max(~x12.5))
200ns wide 70mV high signal

With this info a rough calibration was established:
for the 2V range an ADC unit is 2000mV/16384=0.122mV
the 70mV (~1MeV) correspond to 574 ADC units which
with the change of gain 6*2/20/12.5=0.048
become 27.6 ADC units. We checked with Gasific
that roughly 1 ADC unit corresponds to 2 EFIR units
thus the calibration is 1/2/27.6=0.018 MeV/unit
NOTE: the calibration in online spectra taken
before noon Sunday 6 was wrong by a factor 2
too large!!!!


Si detector (Top and Bottom halves):
Signal from preamplifier in the low gain mode for the measurement:
we see nothing on the scope with 60Co source. In the high gain mode
we saw the other day a negative 6microsec wide 1mV high
signal with a 60Co.

AIDA plastic veto:
The signal from the PMT is going through a CAEN 
shaping amplifier. The signal has a bipolar shape
with a rise time of 500ns a total width of 2microsec
and a height of 100mV (60Co)

F11 ToF plastic (Left and Right):
The signals are processed  in the same way that the
plastic veto detector with TFA using the same settings.
Polarity of the signal unknown.
Currently we see no signal seems its not connected.
We found later that the NIM crate where the 
TFA  were sitting was not on!
We just made a  calibration with beam particles
LISE was used to estimate an energy loss of 65 MeV for the ions.

We looked at the overnight background run (161105_0935_BackgroundOvernight.root), There are gamma-peaks that could be related to neutron inerastic scattering. We identified 565, 596, 608 and 69 keV. They might be related to the effect of neutrons. If this is the correct assignment, this would mean at least some of the neutrons are not thermal when they interact with the germanium. 

There was also significant drift in the Ge gain (seen on the pulser) this may effect the shape of these peaks. 

Some gain drift was also seen on He preamps during this run. The cause is yet to be determined. It is also yet to be determined if these gain shifts are correlated. 

Measurement overnight

Start: around 1:00
Stop: 9:35
File: 161105_0935_BackgroundOvernight.root

The background level after removing the 252Cf source
from the hall dropped to 0.4n/s.

During the night there were neutron rates up to 120 n/s (see figure)

There is a huge spike in the rates which coincides with the time of 
LN2 filling. One can see spike in several spectra (not in all)
One can see also a structure superposed

The rate per rings is also shown. The outer rings see
a higher rate.

Also shown is the comparison of He107 one  (blue) of the outer ORNL2 tubes
with He084 one (red) of the inner ORLN2. The increase in count rate
is about 30%. 

Also shown is the comparison of two external tubes on the top and the bottom:
He107 (blue) and He137 (red), ORNL2 tubes.  There is no increase in count rate.

Also shown is the comparison of a tube above the lead shielding He028 (blue)
and behind the lead shielding He048 (red), UPC tubes. There is no difference.

There is also  comparison between the rate in the CLOVERS and BRIKEN.
Without beam the rate in the Clovers is around  100 g/s against 0.4 n/s in BRIKEN
At the maximum both rates are similar around 130 c/s.

There is also a plot of the gamma-neutron correlation.
We see that there are neutrons which are detected before
the gammas. A possible explanation several neutrons are produced
one is detected first the second later produces a gamma.