Design and test of irradiation-related components in ITER radial x-ray camera

Liqun Hu ,Chen Feng ,Hong Yu ,Xin Sheng ,Jing Zhan ,B Zhang ,S Li ,Nan Zhou ,Y Chen ,Lijuan Niu ,Junsong Shen ,K Chen ,Shijun Qin ,Jian Ge ,Hongchao Cao ,Jianling Zhao ,S Zhang

doi:10.1051/epjconf/201817002003

Liqun Hu , Chen Feng + Show 15 more

Open Access

https://doi.org/10.1051/epjconf/201817002003

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Abstract

International Thermonuclear Experimental Reactor radial X-ray camera is designed to measure the poloidal profile of the plasma X-ray emission with high spatial and temporal resolutions and will be installed inside equatorial port 12. Due to the harsh environment of neutron and gamma radiations, nuclear radiation hardness of many components has to be considered in design and test, including silicon detector array, electronics, and cabling. As for electronics put in a port cell, a preliminary design of highly integrated preamplifier and program controllable mid-amplifier has been completed, and many tests have been done to investigate the radiation hardness performance of the amplifiers together with detectors. In the Cf-252 neutron test with flux of $\sim 2.23\times 10^{3}\,\,\text {n}\cdot \text {cm}^{-2}\cdot \text {s}^{-1}$ and fluence greater than $1.0\times 10^{10}\,\,\text {n}\cdot \text {cm}^{-2}$ , there was no performance degradation in detector and preamplifier. In the Co-60 gamma test with a dose rate of $0.5\,\,\text {Gy}\cdot \text {min}^{-1}$ and an accumulated dose of 200 Gy, the performance change was not found in preamplifier and mid-amplifier except for some radiation damage to the power module in the board of preamplifier. In the following accelerator neutron test where the neutron flux is $\sim 5\times 10^{7}\,\,\text {n}\cdot \text {cm}^{-2}\cdot \text {s}^{-1}$ and neutron fluence is $2\times 10^{12}\,\,\text {n}\cdot \text {cm}^{-2}$ , the functional problem was not found in preamplifier and cable, while there were occurrences of single-event effect in mid-amplifier. The detector underwent 10% decrease of sensitivity to visible light. In addition, shielding cabinet was designed to provide good protection for electronics inside.

Highlights

Due to harsh environment of neutron and gamma radiation, nuclear radiation hardness of many components has to be considered in design and test, including silicon detector array, electronics, cabling, and remote handling during maintenance
To protect detector against neutron damage, boron carbide blocks are envisaged to put in front of and around detectors to mitigate neutron flux onto detector
Apart from neutron damage to detector, another important factor to camera design is maintenance under the condition of activation, especially during DT phase. Considering this factor, remote handling strategy has been worked out based on ITER remote handling procedure and tooling

Summary

Introduction

Due to harsh environment of neutron and gamma radiation, nuclear radiation hardness of many components has to be considered in design and test, including silicon detector array, electronics, cabling, and remote handling during maintenance. A concrete shielding shell enclosing the external camera is designed to reduce radiation leakage into outside environment.

Results

Conclusion