Silicon on Insulator Pixel Detector for X-ray Imaging
S. Muto1, T. Miyoshi2, 4, N. Tamura1, H. Nakanishi1, 4, Y. Itoh1, K. Tsukada3, R. Nishimura4, T. Tsuru5, Y.
Ono6, Y. Arai2, 4,
1

National Institute for Fusion Science, 322-6, Oroshi, Toki, Gifu, JAPAN2

Institute of Particle and Nuclear Studies, High Energy Accelerator Research
Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki, JAPAN

3

Department of Technical Support, Nagoya Institute of Technology, Gokiso, Showa,Nagoya, Aichi, JAPAN4

The Graduated University for Advanced Studies, Hayama, Kanagawa, 240-0193,
JAPAN

5Physics, Kyoto Univ., Kitashirakawa-Oiwake-Cho, Sakyo, Kyoto, JAPAN

6Graduate School of Frontier Sciences, Division of Transdisciplinary Sciences,
The University of Tokyo, Hongo, Bunkyo, JAPANe-mail: mutos@nifs.ac.jp

1.

Objective

X-ray Imaging by means of One Photon Detection to Study Impurity Transport.

2.

Appratus

2.1.

Silicon on Insulator Pixel Detector (SOIPIX)- is a kind of LSI chip. [2]- is being developed by using CAD system for circuit, layout diaphragms, and simulation.
- is processed on a semiconductor wafer of silicon on insulator.
- is both thick high-resistive radiation sensor and CMOS readout circuit. [See Fig. 1]- consists of 264×264 pixels in size of 14 μm square.
- measures an x-ray photon of 20 keV with a quantum efficiency of 40 %.
- measures the x-ray photon in a range more than 3 keV.
- reads out signal in a fast time of 1 μs/pixel.

Fig. 1. Schematic view of SOIPIX [3].

2.2.

Optics- is a typical pinhole camera.
- consists of a position adjustable 100-μm-diameter pinhole and a vacuum-tight-250-μm-thick beryllium filter.

3.

Performance

3.1. Data Acquisition and Control Signals- are transferred through ethernet I/F consisting of an on-board FPGA.

3.2. Energy Resolution- is estimated from the experimental results in LHD.
- is approximately 70 % in compared with a pulse height analyzer (PHA) operated in a counting rate of 64
kcps.

3.3. Counting Rate
- is estimated from the experimental results in LHD.
- is approximately 70 % in compared with the PHA.

3.4.

Improvement of Performance- is in progress to obtain second times larger counting rate.

4.

Available data by “Retrieve”

4.1. LABCOM- is compatible.

5.

Remarks

The SOIPIX and the on-board FPGA are vacuum compatible.
The SOIPIX is cooled to less than -50 °C by a refrigerator.
The assembly of the SOIPIX will be installed at a port in LHD.
Detailed manual will be also submitted.
The performance has been carried out at 7-O port.
The distance has been approximately 16 m far from the LHD plasma.

References[1] “Impurity Transport Study of Medium-Z Argon by means of Soft X-ray Pulse Height Analyzer in LHD”,
S.Muto et al., Plasma and Fusion research 2, S1069, 2007.
[2] “Development of SOI Pixel Process Technology”, Y. Arai, et al., Nucl. Instr. and Meth A. Vol. 636, Issue 1,Supplement, pp. S31-S36. doi:10.1016/j.nima.2010.04.081.
[3] “Development of Energy Resolved X-ray Video Camera”, Y. Arai, et al., Annual Report 2012 (NIFS).
[4] “Development of Energy Resolved X-ray Video Camera in the LHD”, Y. Arai, et al., Annual Report 2013(NIFS).
[5] “Energy Resolved X-ray Video Camera system in LHD”, Y. Arai, et al., Annual Report 2014 (NIFS).