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Fusion neutron activation experiments have been carried out to investigate the activation of metal materials in Experimental Advanced Superconducting Tokamak (EAST). Some cylindrical samples made of stainless steel 316L, carbon steel (A3), high purity cadmium (Cd), oxygen-free copper (Cu), and high purity aluminum (Al) were transported to Port G in the EAST hall for neutron irradiation. The characteristic gamma rays emitted by activated samples were measured with a spectrometer consisting of a digital multichannel analyzer (MCA) and a high purity germanium (HPGe) detector. Qualitative identification of the dominant radionuclides and quantitative measurement of the specific activity have been performed. The experimental results indicated that the high radioactive nuclides with short half-life were produced, such as 56Mn in 316L and A3, 28Al in Al, 66Cu in Cu, and 111m Cd in Cd. Moreover, the long half-life radionuclides were generated in 316L, A3, Cu and Cd samples, which will become the major factors on environment and personnel. In addition, the normalized dose rate at 10 cm in the air of 316L, A3, Al, Cd, and Cu was 1.53 × 10−23, 4.83 × 10−24, 5.57 × 10−23, 4.90 × 10−24 and 1.10 × 10−23 Sv/h/n, respectively. Finally, the comparison between the experimental neutron activation results and the predicted quantities calculated with FISPACT-2007 was discussed. [ABSTRACT FROM AUTHOR]

Radiation rays, especially gamma rays, are produced during nuclear fusion plasma discharge. To obtain the gamma rays around the Experimental Advanced Superconducting Tokamak (EAST) during nuclear fusion plasma discharges, Ar-based gamma ray detectors have been adopted in this article, and to fully monitor the gamma ray dose rates inside the EAST hall, three gamma ray detectors have been set at three selected radiation monitoring sites. Due to the long distances between the monitoring personal computer (PC) and each radiation monitoring site, the monitoring system based on the RS-485 differential communication mode has been designed and set up. With each plasma discharge, the gamma ray radiation field undoubtedly appears as a pulsed radiation field in the EAST hall. Based on the gamma ray dose rates obtained by the monitoring system, the pulsed radiation field of gamma ray dose rates has been carefully studied during one lower hybrid current drive (LHCD)-based plasma discharge. Finally, the exponential function model of the gamma ray dose rates during one plasma discharge in the EAST hall was well obtained and presented. [ABSTRACT FROM AUTHOR]

Radiation particles and rays will be produced during each nuclear fusion plasma discharge, especially neutrons which will be largely emitted out with high intensity and energy under the neutral beam injection (NBI) discharge mode. To well obtain the neutron dose rates during the nuclear fusion plasma discharge, 3He-based neutron detector is adopted in this paper, and to fully obtain the neutron dose rates in the Experimental Advanced Superconducting Tokamak (EAST) hall, three neutron detectors have been set at three selected monitoring sites with a long distance to the monitoring personal computer (PC), and the monitoring system, based on the RS-485 differential communication mode, was designed and setup. Along with each nuclear fusion plasma discharge, the neutron radiation field should appear as a pulsed radiation field. Based on the neutron dose rates, saved by the monitoring system, the neutron radiation dose rates were studied during one NBI-based nuclear fusion plasma discharge. Finally, the Gaussian function model of neutron dose rates during one nuclear fusion plasma discharge was obtained and presented. [ABSTRACT FROM AUTHOR]