U: (Up: 2 RIKEN tubes at 40cm from AIDA)
D: (Down: 12 RIKEN tubes at 80cm from AIDA)
US: (2 ORNL 2" tubes close to the floor at 1.8m from AIDA)

Natural background:
File: 150426_Bckg_1425_1805.root
Rate per tube (n/s): U=0.0071, D=0.0045, US=0.0222
Notes: 
-This rate seems quite small but we should remember 
that we are underground. 
-The fact that U is larger than D could be explained as 
related that the amount of PE around tubes is larger. 
-For comparison: 
BELEN-20@JYFL=0.6n/s (no beam), 0.9n/s (beam)
BELEN-30@GSI=1.2n/s (beam)
BELEN-48@JYFL=1.5n/s

110Zr setting:
File:150501_16111810_110Zr.root
Rate per tube (n/s): U=0.483, D=0.139, US=0.292
Ratio to background: U=68.3,  D=31.1,  US=13.2

Individual tube distribution:
U1	0.280	D1	0.087	D7	0.084	US1	0.132
U2	0.249	D2	0.092	D8	0.084	US2	0.188
		D3	0.083	D9	0.077		
		D4	0.075	D10	0.070		
		D5	0.073	D11	0.069		
		D6	0.065	D12	0.054		

Notes:
-There is huge increase of with beam
-The drop of increase with distance is consistent
with either beam induced or decay of implants

110Zr setting:
File: 150501_1733_1900_110Zr.root (actually 02/05)
Rate per tube (n/s): U=0.869, D=0.242, US=0.516
Ratio to 1st 110Zr: U=1.80,  D=1.74,  US=1.77
Notes:
-We don't quite understand the reason for the near factor two
difference since apparently the settings are the same and beam was
rather stable

In order to investigate the point of origin of the neutrons
we add extra PE covering D5,D6,D11,D12 from the top and
D1,D2,D7,D8 from the front

88Ge setting:
File: 150502_21502333_88Ge.root
Rate per tube (n/s): U=1.271, D=0.349, US=0.706
Ratio to 1st 110Zr: U=2.63,  D=2.51,  US=2.42

Individual rates:
U1	1.340	D1	0.424	D7	0.402	US1	0.576
U2	1.202	D2	0.446	D8	0.381	US2	0.835
		D3	0.408	D9	0.342		
		D4	0.393	D10	0.315		
		D5	0.359	D11	0.250		
		D6	0.275	D12	0.193		

Notes:
-One notices a relative drop of rate for D6, D11 and D12
pointing to a source located in the vicinity of AIDA

94Se setting:
File: 150503_1219_1319_94Se.root
Rate per tube (n/s): U=1.267, D=0.349, US=0.717
Ratio to 1st 110Zr: U=2.62,  D=2.51,  US=2.46
Notes:
-Very similar to 88Ge measurement

Photos of the general arrangement and details of the new PE blocks

94Se setting:
File: 150503_1500_1554_94Se.root
Rate per tube (n/s): U=0.966, D=0.263, US=0.538
Ratio to 1st 110Zr: U=2.00,  D=1.89,  US=1.84
Notes:
-Compared to the 1st 94Se setting measurement (12:19-13:19)
there is a drop of 25% in the rate without apparent reason

For EURICA measurements degrader thickness were increased
trying to decrease MACI and AIDA trigger rate
Before we had 5.7 mm of Al
Now we have: 
Degrader: 4.0 + 1.0 + 0.6 + 0.4 +0.3 = 6.3 mm of Al
also 2x 0.8mm Al plates were added before 
the MACI start detector (thus covering partially AIDA)
Trigger from AIDA will be taken from 3rd DSSSD

Failure of a quadrupole triplet at BigRIPS (some time after earthquake)

We take the chance of measuring background:

File: 150504_1500_2047_bckg.root
Rate per tube (n/s): U=0.098, D=0.0062, US=0.0200
Ratio to 1st 110Zr: U=1.38,  D=1.99,  US=0.90
Notes:
-Compared to the 1st background measurement there are changes
larger than expected statistical fluctuations: 
perhaps due to slight changes in noise

Beam still down. New background measurement
with new RIKEN tube below the MUSIC chamber 
(call it B)

File: 150505_0040_1130_aprox_bckg.root
Average rate per tube (n/s): U=0.0073, D=0.0065, B=0.0070

The Al degrader thickness was reduced to 4.8mm

After the long shutdown the beam is back at 00:30 (06/05)
Intensity is slightly lower 26pnA and somewhat unstable (short time)
Measurement in the morning:
File: 150506_0846_0915_94Se.root
Average rate per tube (n/s): U=3.39 D=0.93B=0.40
Notes:
-The rate has increased by 3.5 in the detectors close to EURICA (!?)
-The rate at the detector below the MUSIC is substantial. 
From the different magnitudes it is clear that neutrons are originated
both outside and inside EURICA.

Measurement of the 252Cf source at the central position

Efficiency and neutron-gamma correlations

Listmode: 160719_2233_252Cf_XX.dlt, Run: 029-030
Online: 160719_2233_252Cf_029_030.root

Measurement with preamplifiers after drying.

Amplifiers are brought back after ~12h and connected.
Measurement of background for 1hour
Online: 160720_1350_1452_Bkg.root
Listmode: No

There might have been a slight improvement on the PA behaviour
but is not clear.

Attached a screen shot of the spectrum

The spurious signals show very little noise superimposed
as can be seen in the attached capture of the sample by the DACQ
but is not so obvious how this can help to veto them. 

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

Background measurement with remaining tubes (95) overnight

Listmode: 160719_2343_Bkg_*.dlt, Run: 031-044
Online: 160719_2343_1030_Bkg.root

Unfortunately the 252Cf source remained ind the hall (shielded and far away but still)

Screen shot of neutron spectrum

During the 98,100Kr setting run we observe 
in the time correlation plot (middle right panel)
of beta signals (marked by AIDA, with amplitude larger than ch=600)
with Riken 3He tube signals (noise and pulser cleaned) 
a small peak around t=0 which might be indication 
of beta-delayed neutrons.
The spectrum was measured for about 2h.

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

3He tube drawings and technical details: 
RIKEN, UPC, GSI, ORNL-1, ORNL-2

START
Assembly and commissioning of BRIKEN neutron detector 

The hybrid configuration of the BRIKEN neutron detector will be assembled at BF2 for the first time with 140 3He
tubes and 2 CLOVER detectors, connected to the Gasific digital data acquisition system and tested with 252Cf
sources.

A list of the available hardware

Drawings of the polyethylene neutron moderator and table assembly

Drawings and specs of 3He tubes

Tube distribution in the moderator, pre-amplifiers and digitizers