2 J-PARC - - PowerPoint PPT Presentation
@J-PARC J-PARC/MLF 2 J-PARC MLF
Optical fiber 35 cm Effective area: 128 x 128 mm2 35 cm
BL17
BL03 BL19
1-d large area scintillator detector
He-3 PSD 2-d large area scintillator detector using WLSF 2-d compact scintillator detector using WLSF
BL18 BL01, BL02, BL08, BL09, BL11, BL12 BL14, BL15, BL16, BL17, BL20, BL21
MWPC He-3 detectors (commercially available) Scintillator detectors
BL16, BL17 RPMT
Multi-wire proportional counter
Single crystal diffractometer (2010 - 2013)
Bio-single crystal diffractometer ( 2007 – 2008, 2011 - )
(2007 – 2009)
TAKUMI: Engineering Materials Diffractometer for Residual Stress Analysis
(each 5 installed at 2q=90 degree position)
The detector should have Sensitive area: 1000 mm x 200 mm Position resolution: 3mm 360 pixels / detector Detection efficiency: >50%@1Å Gamma sensitivity: <10-6@1.3MeV
Sensitive area：1m×20cm Radius curvature：R=2m Number of PMT：48/detector Number of Pixels: 360 Resolution：3mm
217mm 1370mm 805mm
Detector size without PMT：805×1370×217mm Detector size with PMT: 805×～2000×217mm weight：～120kg（without PMT） weight：～180kg（with PMT）
Senstive Area （1m×20cm）
Neutrons
Detection of scintillation light from both sides of scintillator Increase of detection efficiency using scintillators tilted to neutron direction(Effective thickness increased)
Scintillators (ZnS/6LiF) Reflectors resolution ： 3mm
Fibers Reflectors Scintillators (ZnS/6LiF) Scintillators
6Li + n→3H + a+ 4.8 MeV
Neutron
B4C Block
The scintillation light was collected with
to PMT and Data acquisition system
PMT & DAQ
No.3 200 400 600 800 1000 1200 1400 50 100 150 200 250 300 350
No.4 200 400 600 800 1000 1200 1400 50 100 150 200 250 300 350 channel number Counts/100s
Gamma sensitivity <10-6 with a 60Co source (at discri. level of 250mV)
10-8 10-7 10-6 10-5 10-4 100 150 200 250 300 350
Detector 1 Detector 2
Gamma sensitivity Threshold level (-mV)
Detection efficiency : > 50% (1.8Å) Spatial resolution : < 1 mm Gamma sensitivity : < 10-6 Packing density : ～70% Compact Specifications required to detector
High speed amplifier discriminator module
256 x 256 ch imaging detector with WLS readout
Signal processing module with FPGAs
Prototype detector (in 2008)
High detection efficiency
neutron Neutron-sensitive scintillator neutrons Ｘ Ｙ
Conventional structure iBIX structure Single Scintillator screen Double scintillator screens
WLS fibres
(2) Packed ½-mm diameter WLS fiber ribbons High spatial resolution (1) Developed a ZnS/10B2O3 scintillator and double the number of screens
0.2 0.4 0.6 0.8 1 1.2 1.4 20 40 60 80 100 Position (x axis) [mm] exprimental data fitted cumulative distribution function
Spatial resolution (FWHM) = SQRT(2log2) σ ~ 2.3548 σ = 1.19 [mm], including beam divergence Edge Spread function:
A = 0.5 → 0.4483 B = 0.1 → 0.09343 μ = 50 → 50.41 σ = 0.5 → 0.5082
with Gd mask without Gd mask Fitting parameters
255 255 Y X
Gd mask
* SENJU : A time-of-flight Laue single crystal diffractometer * A large area position-sensitive scintillator detector using WLS fiber technology
Spatial resolution : ~4 mm Detection area : ~30 x 30 cm2 Detection efficiency : >40%@1.8Å Gamma-ray sensitivity : < 10-6
Specifications required to detector
Detector head
Signal processing & Encoder electronics DAQ electronics
In the design, to increase a detector coverage at an affordable cost the WLS fibers are placed at a regular pitch of 4 mm.
Scintillator (front)
① WLS fibers ③ Clear fibers neutron ②ZnS/10B2O3 scintillators
Key Designs
0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 100 200 300 400 500 relative counts elapsed time, days
Det12-01(SCDD01_DS-01)
10 20 30 40 50 60 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 detection efficiency, % detector number
production date: 2010.10 2013.1
Detector efficiency of 37+2 detectors Count stability over time
Detectors were stable after >400 days
0.2 0.4 0.6 0.8 1 1.2 20 25 30 35 40
intensity, a.u. Image plate SCD detector
Pencil beam ( ~3 mm in width, 4 Å)
Collimator Collimator
Spatial resolution : 4 mm
Detection efficiency ～40%@1.8Å Gamma-ray sensitivity ～3x10-6@1.3MeV
Mass production technique is acceptable.
Gamma sensitivity vs Detection efficiency of 30 detectors Earthquake
High spatial resolution detector pixel size : 0.5 x 0.5 mm detective area : 133 x 133 mm2 detector efficiency: ~50% for 1.8Å gamma sensitivity: ~1 x 10-6
信号処理& データ収集系
Large area detector pixel size : 4 x 4 mm detective area : 256 x 256 mm2 detector efficiency: ~40% for 1.8 Å gamma sensitivity: ~ 3 x 10-6
300 x 300 mm
Total 30 detectors were installed and in service now Total 37 detectors were installed and in service now
Optical fiber 35 cm Effective area: 128 x 128 mm2 35 cm
Installed in MLF/BL17 Pressure vessel withstanding up to 8 atm Multi-wire type detector element Wire pitch: 1 mm Sensitive area: 128 x 128 mm2 ASD-ASIC for multi-channel signal processing Individual line readout Optical signal transmission
Sharaku: Polarized Neutron Reflectometer
200 400 600 800 1000 10 15 20 25 30 35 40 Measured signal (counts) Position (mm)
X projection 1.8 mm FWHM
2x10
4
4x10
4
6x10
4
8x10
4
1x10
5
1.2x10
5
20 40 60 80 100 120 Counts Position (mm)
Standard deviation
10-5 10-4 10-3 10-2 10-1 100 101 102 103 10-6 10-5 10-4 10-3 10-2 10-1 100 101 102
500 1000 Measured counts (kcps) Reactor power (MW) Elapsed time (s)
■ Reactor monitor
10-1 100 101 102 103 104 105 10-5 10-4 10-3 10-2 10-1 100 101 Counts (cps) Reactor Power (MW)
beam size: 0.3 x 0.3 mm2
1D uniformity X: 3.5% Y: 4.6%
With Cf-252 At KUR Good linearity