Design of ITER neutron flux monitor system back-end electronics

Abstract

The primary aim of the International Thermonuclear Experimental Reactor (ITER) Neutron Flux Monitor (NFM) system is to diagnose the total neutron emission rate and fusion power of the plasma fusion reaction. The neutron flux is measured directly by the system and the fusion power can be calculated according to the neutron flux result. The NFM system is composed of detectors and back-end electronics. This paper focuses on the work of NFM#7 back-end electronics design and development. The back-end electronics consist mainly of four parts: Firstly, the pre-amplifiers are used to charge integrate and amplify the signal of fission chambers. Secondly, the output of pre-amplifiers will be transmitted to Signal Processing Unit (SPU) for analog signal conditioning, data processing, and measurement result uploading. Thirdly, pre-amplifiers and fission chambers have different electricity sources. Pre-amplifiers receive electricity generated from low voltage power whilst fission chambers receive electricity generated from high voltage power. Lastly, the Instrument and Control (I&C) is designed as the interface between NFM hardware and ITER central system and its functions are configuration & control, monitoring, calibration, data communication & archiving and clock synchronization. All the four parts are well integrated and tested in neutron field. The system design also follows the guidelines and standards of ITER.