計測システム研究会 @J-PARC J-PARC/MLF における 2 次元ガス検出器及び シンチレータ検出器の開発 J-PARC センター 物質生命科学ディビジョン 坂佐井 馨
MLF ビームラインにおける検出器の現状 He-3 detectors (commercially available) Scintillator detectors He-3 PSD 2-d compact scintillator detector using WLSF BL01, BL02, BL08, BL09, BL11, BL12 BL14, BL15, BL16, BL17, BL20, BL21 BL03 Effective area: Optical fiber 128 x 128 mm 2 1-d large area scintillator detector 35 cm BL19 MWPC 35 cm BL17 2-d large area Multi-wire scintillator detector proportional counter using WLSF BL16, BL17 RPMT BL18
Outline シンチレーション検出器の開発 - 1 次元シンチレーション検出器 - 2 次元シンチレーション検出器 2 次元ガス検出器の開発 - マルチワイヤ型検出器
ML MLF におけるシンチレーション検出器 BL19(Takumi) Residual stress diffractometer (2007 – 2009) Linear scintillation detector BL18(Senju) Single crystal diffractometer BL03(iBIX) (2010 - 2013) Bio-single crystal diffractometer ( 2007 – 2008, 2011 - ) 2-D detector using WLSF 2-D detector using WLSF
Outline シンチレーション検出器の開発 - 1 次元シンチレーション検出器 - 2 次元シンチレーション検出器 2 次元ガス検出器の開発 - マルチワイヤ型検出器
BL19 における 1 次元シンチレーション検出器 Developed under collaboration with ISIS, RAL Sample Neutron Number of detectors: 10 Specifications of Detectors 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 Detectors (each 5 installed at 2 q =90 degree position) TAKUMI: Engineering Materials Diffractometer for Residual Stress Analysis
BL19 における 1 次元シンチレーション検出器 Scintillation Detector using ZnS/LiF 1370mm 805mm Neutrons 217mm Senstive Area （ 1m × 20cm ） Sensitive area ： 1m × 20cm Detector size without PMT ： 805 × 1370 × 217mm Radius curvature ： R=2m Detector size with PMT: 805 ×～ 2000 × 217mm Number of PMT ： 48/detector weight ：～ 120kg （ without PMT ） Number of Pixels: 360 weight ：～ 180kg （ with PMT ） Resolution ： 3mm
BL19 検出器のヘッドの構造 Scintillator & grids Venetian Head Detection of scintillation light from both sides of scintillator Increase of detection efficiency using scintillators tilted to neutron direction (Effective thickness increased) resolution Neutrons ： 3mm Neutron Scintillators Scintillators (ZnS/ 6 LiF) Reflectors (ZnS/ 6 LiF) 6 Li + n→ 3 H + a + 4.8 MeV Fibers Reflectors The scintillation light was collected with Scintillators optical fibers and sent to PMT and Data acquisition system B4C Block PMT & DAQ
BL19 検出器の性能 Gamma sensitivity Uniformity measured with PE rod No.3 10 -4 1400 Detector 1 1200 Detector 2 1000 10 -5 Gamma sensitivity 800 600 5.5%@std.dev 400 200 0 10 -6 0 50 100 150 200 250 300 350 10 -7 No.4 1400 1200 10 -8 Counts/100s 1000 100 150 200 250 300 350 800 600 Threshold level (-mV) 4.7%@std.dev 400 200 Gamma sensitivity <10 -6 0 0 50 100 150 200 250 300 350 with a 60 Co source channel number (at discri. level of 250mV)
BL BL19TA TAKUM UMI 検出器 • 3mm position resolution • Detection efficiency: >50%@1Å • Gamma sensitivity: <10 -6 @1.3MeV • 3 × 196mm detector element • 360ch/detector • Total 10 detector Total 10 detectors were • Total 3600 elements installed and have been in • 2.0m 2 active area service for several years • 75 ° <2 q ＜ 105 °
Outline シンチレーション検出器の開発 - 1 次元シンチレーション検出器 - 2 次元シンチレーション検出器 2 次元ガス検出器の開発 - マルチワイヤ型検出器
BL BL03 における 2 次元シンチレーション検出器 • iBIX : Single crystal diffractometer for bio-molecular crystallography • A first WLS-fiber-based scintillator detector developed at the J-PARC. Specifications required to detector Detection efficiency : > 50% (1.8Å) Spatial resolution : < 1 mm Gamma sensitivity : < 10 -6 Packing density : ～ 70% Compact Prototype detector (in 2008) 256 x 256 ch imaging detector with WLS readout Signal processing High speed amplifier module with FPGAs discriminator module
iB iBIX 検出器のヘッド構造 iBIX structure Conventional structure neutron neutrons WLS fibres Ｙ Ｘ Neutron-sensitive scintillator Double scintillator screens Single Scintillator screen (1) Developed a ZnS/ 10 B 2 O 3 scintillator High detection efficiency and double the number of screens (2) Packed ½-mm diameter WLS fiber ribbons High spatial resolution
iB iBIX 検出器の位置分解能 1.4 Edge Spread function: exprimental data fitted cumulative distribution function 1.2 without Gd mask 1 0.8 Fitting parameters 255 0.6 A = 0.5 → 0.4483 B = 0.1 → 0.09343 Y 0.4 μ = 50 → 50.41 Gd mask σ = 0.5 → 0.5082 with Gd mask 0.2 0 0 255 X 0 0 20 40 60 80 100 Spatial resolution (FWHM) Position (x axis) [mm] = SQRT(2log2 ) σ ~ 2.3548 σ = 1.19 [mm], including beam divergence
BL BL18(Senju ju) の 2 次元シンチレータ検出器 * SENJU : A time-of-flight Laue single crystal diffractometer * A large area position-sensitive scintillator detector using WLS fiber technology Specifications required to detector Spatial resolution : ~4 mm Detection area : ~30 x 30 cm 2 Detection efficiency : >40%@1.8Å Gamma-ray sensitivity : < 10 -6 Signal processing & Encoder electronics Detector head DAQ electronics T. Nakamura, et al. NIMA686(2012)64.
BL18 検出器のヘッド構造 BL In the design, to increase a detector coverage at an affordable cost the WLS fibers are placed at a regular pitch of 4 mm. ③ Clear fibers ① WLS fibers neutron Scintillator (front) ② ZnS/ 10 B 2 O 3 scintillators (1) WLS fiber placed at a 4-mm pitch Large area Key Designs Detection efficiency (2) Two scintillator screens (3) Bend clear fiber backward Minimize dead area
BL18 検出器の性能 Collimator Collimator Count stability over time 1.2 Det12-01(SCDD01_DS-01) Image plate 1.2 1 SCD detector 1.1 Pencil beam 0.8 relative counts 1.0 intensity, a.u. ( ~3 mm in width, 4 Å) 0.9 0.6 0.8 Detectors were stable Earthquake 0.4 Spatial resolution : 4 mm 0.7 after >400 days 0.6 0.2 0.5 0 0 100 200 300 400 500 elapsed time, days 20 25 30 35 40 position. mm Detector efficiency of 37+2 detectors Gamma sensitivity vs Detection efficiency of 30 detectors 60 production date: 2010.10 2013.1 50 detection efficiency, % 40 30 Detection efficiency 20 ～ 40%@1.8Å Mass production technique is acceptable. Gamma-ray sensitivity 10 ～ 3x10 -6 @1.3MeV 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 detector number
波長シフトファイバを用いたシンチレーション検出器 BL03(iBIX) BL18(SENJU ) 300 x 300 mm 信号処理 & データ収集系 Large area detector High spatial resolution detector pixel size : 4 x 4 mm pixel size : 0.5 x 0.5 mm detective area : 256 x 256 mm 2 detective area : 133 x 133 mm 2 detector efficiency: ~40% for 1.8 Å detector efficiency: ~50% for 1.8Å gamma sensitivity: ~ 3 x 10 -6 gamma sensitivity: ~1 x 10 -6 Total 30 detectors were installed Total 37 detectors were installed and in service now and in service now
Outline シンチレーション検出器の開発 - 1 次元シンチレーション検出器 - 2 次元シンチレーション検出器 2 次元ガス検出器の開発 - マルチワイヤ型検出器
BL BL17 におけるマルチワイヤ型検出器 Effective area: Optical fiber 128 x 128 mm 2 35 cm Sharaku: Polarized Neutron Reflectometer 35 cm MWPC system 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 mm 2 ASD-ASIC for multi-channel signal processing Individual line readout Optical signal transmission
開発した MW MWPC の性能評価 Irradiation experiments were performed using Cf-252 at KUR/CN3 at J-PARC/MLF BL17 MWPC MWPC
Performances of MWPC Counting uniformity Output Linearity Position resolution 10 3 10 2 ● Measured by developed detector ■ Reactor monitor 10 2 10 1 10 1 10 0 Measured counts (kcps) Reactor power (MW) 10 0 10 -1 10 -1 10 -2 10 -2 10 -3 10 -3 10 -4 With Cf-252 10 -4 At KUR 10 -5 10 -5 10 -6 -500 0 500 1000 beam size: 0.3 x 0.3 mm 2 Elapsed time (s) 1000 5 1.2x10 10 5 X projection Good linearity 5 1.8 mm FWHM 1x10 800 10 4 Measured signal (counts) 4 8x10 10 3 600 Counts (cps) Counts Standard deviation 4 6x10 1st. cathode: 3.8% 10 2 400 2nd. cathode: 4.6% 1D uniformity 4 4x10 10 1 200 X: 3.5% 4 > 5 decades! 10 0 2x10 Y: 4.6% 0 10 15 20 25 30 35 40 10 -1 0 Position (mm) 10 -5 10 -4 10 -3 10 -2 10 -1 10 0 10 1 0 20 40 60 80 100 120 Reactor Power (MW) Position (mm)
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