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

Optical fiber

35

cm

Effective area: 128 x 128 mm2

35 cm

BL17

BL03

BL19

1-d large areascintillator detector

MLFビームラインにおける検出器の現状

He-3 PSD

2-d large area scintillator detectorusing WLSF

2-d compactscintillator detectorusing WLSF

BL18

BL01, BL02, BL08, BL09, BL11, BL12BL14, BL15, BL16, BL17, BL20, BL21

MWPC

He-3 detectors(commercially available)

Scintillator detectors

BL16, BL17RPMT

Multi-wire proportional counter

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

Outline

MLFにおけるシンチレーション検出器

2-D detector using WLSF

BL18(Senju)Single crystal diffractometer(2010 - 2013) BL03(iBIX)

Bio-single crystal diffractometer( 2007 – 2008, 2011 - )

BL19(Takumi) Residual stress diffractometer

(2007 – 2009)

Linear scintillation detector

2-D detector using WLSF

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

Outline

BL19における1次元シンチレーション検出器

Neutron

TAKUMI: Engineering Materials Diffractometer for Residual Stress Analysis

Detectors(each 5 installed at 2q=90 degree position)

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

Sample

Developed under collaboration with ISIS, RAL

BL19における1次元シンチレーション検出器

Sensitive area：1m×20cm

Radius curvature：R=2m

Number of PMT：48/detector

Number of Pixels: 360

Resolution：3mm

Neutrons217mm

1370mm805mm

Detector size without PMT：805×1370×217mm

Detector size with PMT: 805×～2000×217mm

weight：～120kg（without PMT）weight：～180kg（with PMT）

Scintillation Detector using ZnS/LiF

Senstive Area（1m×20cm）

BL19検出器のヘッドの構造

Neutrons

Venetian Head 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

ReflectorsScintillators

(ZnS/6LiF)

Scintillators

6Li + n→3H + a+ 4.8 MeV

Neutron

B4C Block

Scintillator & grids

The scintillation light was collected with optical fibers and sent to PMT and Data acquisition system

PMT & DAQ

No.3

0

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600

800

1000

1200

1400

0 50 100 150 200 250 300 350

BL19検出器の性能

No.4

0

200

400

600

800

1000

1200

1400

0 50 100 150 200 250 300 350

channel number

Counts

/100s

4.7%@std.devGamma 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 1Detector 2

Ga

mm

a s

ensitiv

ity

Threshold level (-mV)

Gamma sensitivityUniformity measured with PE rod

5.5%@std.dev

BL19TAKUMI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 3600 elements

• 2.0m2 active area

• 75°<2q＜105°

Total 10 detectors were

installed and have been in

service for several years

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

Outline

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.

Detection efficiency : > 50% (1.8Å)Spatial resolution : < 1 mmGamma sensitivity : < 10-6

Packing density : ～70%Compact

Specifications required to detector

High speed amplifierdiscriminator module

256 x 256 chimaging detectorwith WLS readout

Signal processingmodule with FPGAs

Prototype detector (in 2008)

iBIX検出器のヘッド構造

High detection efficiency

neutron

Neutron-sensitive scintillator

neutrons

ＸＹ

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

iBIX検出器の位置分解能

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 20 40 60 80 100

Rela

tive inte

nsi

ty

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 → 0.09343μ = 50 → 50.41

σ = 0.5 → 0.5082 with Gd mask

without Gd mask

Fitting parameters

0 2550

255

Y

X

Gd mask

BL18(Senju)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

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

T. Nakamura, et al. NIMA686(2012)64.

BL18検出器のヘッド構造

In the design, to increase a detector coverage at an affordable costthe WLS fibers are placed at a regular pitch of 4 mm.

(1) WLS fiber placed at a 4-mm pitch Large area

(2) Two scintillator screens Detection efficiency

(3) Bend clear fiber backward Minimize dead area

Scintillator (front)

①WLS

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

0 100 200 300 400 500

rela

tive

co

un

ts

elapsed time, days

Det12-01(SCDD01_DS-01)

BL18検出器の性能

0

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

dete

ctio

n ef

ficie

ncy,

%

detector number

production date: 2010.10 2013.1

Detector efficiency of 37+2 detectors

Count stability over time

Detectors were stableafter >400 days

0

0.2

0.4

0.6

0.8

1

1.2

20 25 30 35 40

position. mm

inte

nsity,

a.u

.

Image plate

SCD detector

Pencil beam ( ~3 mm in width, 4 Å)

CollimatorCollimator

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

波長シフトファイバを用いたシンチレーション検出器

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

BL18(SENJU )

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

BL03(iBIX)

300 x 300 mm

Total 30 detectors were installed

and in service nowTotal 37 detectors were installed

and in service now

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

Outline

BL17におけるマルチワイヤ型検出器

Optical fiber

35

cm

Effective area: 128 x 128 mm2

35 cm

MWPC systemInstalled in MLF/BL17

Pressure vessel withstanding up to 8 atm

Multi-wire type detector elementWire pitch: 1 mmSensitive area: 128 x 128 mm2

ASD-ASIC for multi-channel signal processing

Individual line readout

Optical signal transmission

Sharaku: Polarized Neutron Reflectometer

開発したMWPCの性能評価

Irradiation experiments were performed using Cf-252at KUR/CN3at J-PARC/MLF BL17

MWPC MWPC

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10 15 20 25 30 35 40

Measu

red s

ignal

(counts

)

Position (mm)

X projection1.8 mm FWHM

0

2x104

4x104

6x104

8x104

1x105

1.2x105

0 20 40 60 80 100 120

Co

un

ts

Position (mm)

Standard deviation

1st. cathode: 3.8%

2nd. cathode: 4.6%

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 0 500 1000

Measu

red c

ounts

(kcps) R

eacto

r pow

er (M

W)

Elapsed time (s)

● Measured by developed detector

■ Reactor monitor

10-1

100

101

102

103

104

105

10-5 10-4 10-3 10-2 10-1 100 101

Cou

nts

(cp

s)

Reactor Power (MW)

Position resolution Counting uniformity Output Linearity

beam size: 0.3 x 0.3 mm2

1D uniformityX: 3.5%Y: 4.6% > 5 decades!

With Cf-252 At KUR

Good linearity

Performances of MWPC

Summary 計測システム研究会@J-PARC

まとめ

中性子検出器は中性子散乱実験等において、非常に重要な役割を果たしており、このため、我々はJ-PARC/MLFにおいて、様々な中性子検出器を開発してきた。

シンチレーション検出器に関しては, BL19に対しては、大型の1次元検出器を開発した。BL03及び

BL18に対しては波長シフトファイバを用いた2次元検出器を開発した。これらの検出器は共用開始後順調に稼働している。

ガス検出器に関しては、 BL17において、マルチワイヤ型検出器（MWPC）を開発した。位

置分解能や一様性等のMWPCの性能をKUR等で確認した。