期刊：
Journal of Radioanalytical and Nuclear Chemistry,2024年 ISSN：0236-5731
通讯作者：
Gong, XY
作者机构：
[Gong, Xueyu; Huang, Qianhong; Li, Xiang] Univ South China, Sch Nucl Sci & Technol, Changsheng West Rd 28, Hengyang 421001, Peoples R China.;[Li, Xiang] HengYang Normal Univ, Sch Comp Sci & Technol, HengHua Rd 16, Hengyang 421001, Peoples R China.;[Xie, Yuxi] HengYang Normal Univ, Sch Phys & Elect Engn, HengHua Rd 16, Hengyang 421001, Peoples R China.
通讯机构：
[Gong, XY ] U;Univ South China, Sch Nucl Sci & Technol, Changsheng West Rd 28, Hengyang 421001, Peoples R China.
关键词：
Bayesian statistics;Artificial radionuclides monitoring;Beta distribution;Poisson distribution;Gaussian distribution
摘要：
This paper delves into the Bayesian statistics applications of three preeminent models, Poisson distribution, Gaussian distribution, and Binomial distribution, in the continuous surveillance of artificial radionuclides. It introduces a slide-window method to accelerate the updating of the prior distribution of model parameters and compares the performances of three models before and after utilizing this method. Comparisons among the three models are made before and after using the slide-window. Experimental results demonstrate a marked enhancement in the performances of all models.
通讯机构：
[Cao, JJ ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
摘要：
The current driven by neutral beam injection in tokamak is calculated, and the slowing-down distribution function of the fast ion is obtained by the backward Euler iteration method, including the pitch angle scattering collision. This study reveals that when the pitch-angle cosine is small, the trapped fast-ion current significantly contributes to the total driven current, particularly when the neutral beam is injected perpendicularly. In such cases, the current densities of passing and trapped ions are of the same order of magnitude, with the trapped fast-ion current contributing over 10% to the total neutral beam-driven current. This results in a parabolic profile of the total current in the radial direction, promoting the formation of a negative shear equilibrium structure in the core of the tokamak plasma. The numerical approach was validated against the NUBEAM code while considering electron shielding effects and applied to calculate the neutral beam-driven current in multiple tokamaks. The influence of pitch-angle cosine and neutral beam injection power on the driven current was studied at different radial positions. (c) 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution-NonCommercial 4.0International (CC BY-NC) license
关键词：
NBI plus ICRF synergy;fast ion loss;toroidal field ripple;collision effect
摘要：
The loss of ion cyclotron resonance frequencies (ICRF)-heated neutral beam injection ions in experimental advanced superconducting tokamak was numerically investigated by ORBIT code simulations. The effects of collisions and ripples on particle losses were taken into account, and the distributions of fast ions generated by different beams in combination with ICRF heating were calculated using the TRANSP code. Results showed that ICRF waves altered the orbital distributions of beam ions, causing an increase in trapped ions and fast ion losses. Additionally, for co-current injected beams, perpendicular injection resulted in higher fast ion losses in synergistic heating than tangential injection. The study also found that the synergistic effect of collisions and ripples enhanced fast ion losses, which were highly localized and generated a maximum heat load of 0.165 MW m−2 on the first wall. However, conducting synergy heating experiments at high plasma currents and low effective ion charge numbers can significantly reduce the loss of fast ions.
作者机构：
[Yin, Lan; Gong, Xueyu; Zheng, Pingwei; Liu, Yizhuohang; Zheng, PW; Zhong, Yijun] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Zheng, Pingwei; Zheng, PW] Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Yang, Wenjun] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.;[Chen, Xiaochang] Nanchang Univ, Sch Phys & Mat, Nanchang 330031, Peoples R China.
通讯机构：
[Gong, XY ; Zheng, PW ; Zheng, PW] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Peoples R China.
关键词：
spherical torus;stellarator;electron cyclotron wave;start-up;0D model
摘要：
<jats:title>Abstract</jats:title>
<jats:p>According to the physics of tokamak start-up, this paper constructs a zero-dimensional (0D) model applicable to electron cyclotron (EC) wave assisted start-up in NCST spherical torus (spherical tokamak) and CN-H1 stellarators. Using the constructed zero-dimensional model, the results obtained in this paper under the same conditions are compared and validated against references results for pure hydrogen plasma start-up in tokamak. The results are in good agreement, especially regarding electron temperature, ion temperature and plasma current. In the presence of finite Ohmic electric field in the spherical tokamak, a study on the EC wave assisted start-up of the NCST plasma at frequency of 28 GHz is conducted. The impact of the vertical magnetic field <jats:italic>B</jats:italic>
<jats:sub>v</jats:sub> on EC wave assisted start-up, the relationship between EC wave injection power <jats:italic>P</jats:italic>
<jats:sub>inj</jats:sub>, Ohmic electric field <jats:italic>E</jats:italic>, and initial hydrogen atom density nH0 is explored separately. It is found that under conditions of Ohmic electric field lower than ITER (~ 0.3 V m-1), EC wave can expand the operational space to achieve better plasma parameters. Simulating the process of 28 GHz EC wave start-up in the CN-H1 stellarator plasma, the plasma current in the zero-dimensional model is replaced with the current in the poloidal coil of the stellarator. Plasma start-up can be successfully achieved at injection powers in the hundreds of kilowatts range, resulting in electron densities on the order of 10<jats:sup>17</jats:sup> to 10<jats:sup>18</jats:sup> m<jats:sup>-3</jats:sup>.</jats:p>
作者机构：
[Yin, Lan; Chen, You; Yin, L] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.;[Yin, Lan; Yin, L; Gong, Xueyu; Chen, You; Peng, Yaoyi; Ma, Wankun; Zhou, Fangbei; Wang, Shuangshuang] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Yin, Lan; Chen, You; Yin, L] Univ South China, Hunan Key Lab Math Modeling & Sci Comp, Hengyang 421001, Peoples R China.
通讯机构：
[Yin, L; Gong, XY ; Yin, L ] U;Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;Univ South China, Hunan Key Lab Math Modeling & Sci Comp, Hengyang 421001, Peoples R China.
摘要：
<jats:p>In this study, D(H) minority ion cyclotron resonance heating (ICRH) scenarios in Nan Chang spherical tokamak (NCST) were simulated using the full-wave code TORIC. NCST is a low-aspect-ratio (R/a = 1.67) spherical tokamak, with its core plasma parameters characterized by a magnetic field intensity of 0.36 T and a density of 1018 m−3. Our simulation results demonstrate that the ion cyclotron wave can penetrate the core plasma of the NCST more effectively with a lower toroidal mode number, indicating that resonant ions can absorb the wave energy efficiently. Furthermore, it is found that as the minority ion H concentration is increased, a noticeable decline in the left-handed electric field adjacent to the ion cyclotron resonance layer is observed. Optimal heating efficiency is attained when maintaining a minority ion H concentration within the range 5%–10%. The minority ion velocity distribution was simulated to estimate the tail temperature of minority-ICRH, which is expected to exceed 10 keV. The difference in the power efficiency with different plasma compositions [Ar(H) and D(H)] was also simulated. When the H-ion cyclotron resonance layer is located at the core plasma, the power-absorption fraction of H in Ar(H) plasma surpasses that of D and H combined in D(H) plasma under identical conditions. These simulations provide a crucial foundation and theoretical reference not only for NCST but also for other spherical tokamaks conducting ICRH experiments.</jats:p>
作者：
Tao Yang;Hao Wang;Fan Feng;Xiang Liu;Xue-Yu Gong;...
期刊：
钨科技(英文),2024年6(4):759-766 ISSN：2661-8028
通讯作者：
You-Yun Lian<&wdkj&>Jian-Bao Wang
作者机构：
[Xue-Yu Gong] School of Nuclear Science and Technology, University of South China, Hengyang, China;[Hao Wang; Fan Feng; Xiang Liu; You-Yun Lian; Jian-Bao Wang] Southwestern Institute of Physics, Chengdu, China;[Tao Yang] School of Nuclear Science and Technology, University of South China, Hengyang, China<&wdkj&>Southwestern Institute of Physics, Chengdu, China
通讯机构：
[You-Yun Lian; Jian-Bao Wang] S;Southwestern Institute of Physics, Chengdu, China<&wdkj&>Southwestern Institute of Physics, Chengdu, China
摘要：
Tungsten-based materials are one of the most important candidates for the plasma facing materials (PFMs) of future fusion reactors, and it is necessary to study the properties of tungsten-based materials under the service conditions of fusion devices to ensure the long-term steady-state operation of future fusion reactors. In this paper, different tungsten-based materials made by the same rotary swaging process are selected to simulate the transient thermal loads on the PFMs of a fusion reactor using an electron beam, and thermal load experiments are carried out by changing the power density of a loading pulse and the pulse number. It is found that different tungsten-based materials made by the same process have large differences in thermal shock resistance, and the doped tungsten materials (W-K and W-La2O3) are significantly better than the pure tungsten materials with the increase in thermal shock power density and the number of cycles, especially the W-K materials, which have excellent performance.
通讯机构：
[Bin Wu] I;[Xueyu Gong] S;School of Nuclear Science and Technology, University of South China, Hengyang 421001, People's Republic of China<&wdkj&>Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
关键词：
NBI plus ICRF synergy;beam-RF interactions;fast ions;neutron emission rate
摘要：
<jats:title>Abstract</jats:title>
<jats:p>Following an upgrade of the neutral beam injection (NBI) system, obvious synergy between combined NBI and ion cyclotron resonance frequency (ICRF) heating was observed in recent experiments conducted at EAST. To investigate the effects of beam-ions accelerated by radiofrequency (RF) wave, analyses are performed by using TRANSP code based on the experimental results. The calculated results argue that only a small fraction of the ICRF power is absorbed by the beam ions in the ICRF + NBI synergistic heating of the (H)D plasma. To enhance the beam–RF interactions in synergistic heating and achieve high plasma performance of EAST, different experimental conditions, including multiple injection powers and diverse beam injection options, were explored. Beam injected fast ions are passing particles, trapped particles observed when synergy heating between ICRF and NBI. In particular, by varying the injection direction of the beam ions it was observed that more tangential beam yields better synergy in comparison with more perpendicular beam. The neutron emission rate of D–D fusion in tokamaks is improved and less fast ion loss is produced with tangential NBI + ICRF heating. Also, the effect of the ratio <jats:italic>P</jats:italic>
<jats:sub>ICRF</jats:sub>/<jats:italic>P</jats:italic>
<jats:sub>NBI</jats:sub> on ICRF + NBI combined heating is demonstrated, the higher power boosts the fusion enhancement. The study of the performed synergistic heating provides an important reference for the subsequent combined NBI + ICRF heating experiments on EAST.</jats:p>
通讯机构：
[Qianhong Huang; Yijun Zhong] S;School of Nuclear Science and Technology, University of South China, Hengyang, People’s Republic of China<&wdkj&>School of Nuclear Science and Technology, University of South China, Hengyang, People’s Republic of China
作者机构：
[Liu, Haijing; Gong, Xueyu] School of Electrical Engineering, University of South China, 28 West Chang Sheng Road, Hunan, Hengyang;421001, China;[Wang, Fudi; Fu, Jia; Jin, Yifei; He, Liang; Lu, Dian; Bae, Cheonho; Zhang, Hongming; Fu, Shengyu; Ji, Huajian; Lyu, Bo] Institute of Plasma Physics, Chinese Academy of Sciences, 350 Shu Shan Lake Road, Anhui, Hefei;230031, China;[Zhong, Yijun; Huang, Qianhong; Deng, Sheng] School of Nuclear Science and Technology, University of South China, 28 West Chang Sheng Road, Hunan, Hengyang
摘要：
<jats:p>Analyzing the radiation spectra of impurity ions is a widely applied diagnostic scheme for plasma ion temperature and rotation measurements on tokamaks. High precision wavelength calibration is a prerequisite for the accurate measurement of plasma parameters, especially for plasma rotation. Furthermore, the sparseness or absence of the standard spectral lines brings calibration challenges due to the narrow wavelength range. A precise wavelength calibration method is demonstrated in which the comb-like spectra generated by the Fabry–Pérot etalon can lock a series of fixed peaks as reference points in a wide wavelength range. The equal frequency intervals of the comb-like spectra are further corrected using several characteristic neon lines of known wavelengths. The experimental results indicate that the wavelength accuracy obtained by this calibration method is less than 0.005 nm, which corresponds to a rotation speed of 2.3 km/s in the toroidal direction for the beam emission spectroscopy spectrometer installed on the experimental advanced superconducting tokamak. Taking the O V(650.024 nm, n = 4 → 3) line as an example, the maximum difference in the oxygen ion rotation velocity is 3.8 km/s for the absolute rotation of ∼25 km/s, when compared with the calibration results of a standard lamp.</jats:p>
作者机构：
[杨光; 钟翊君; 龚学余; 黄千红] Department of Nuclear Science and Technology, University of South China, Hengyang, 421001, China;[郑平卫] Department of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, China;[王占辉] Institute of Fusion Sciences, Southwestern Institute of Physics, Chengdu, 610000, China
通讯机构：
[Zhong, Y.; Gong, X.] D;Department of Nuclear Science and Technology, China
关键词：
杂质输运;电子回旋波
摘要：
本文基于OMFIT(One Modeling Framework for Integrated Tasks)平台,结合中国环流器二号M(HL-2M)托卡马克装置参数,自洽耦合等离子体平衡、外部辅助加热和电流驱动、输运等物理过程,考虑杂质浓度变化引起的等离子体密度、温度等输运量变化,以及引起的等离子体磁面中心Shafranov位移变化,从理论上进行杂质浓度变化对电子回旋波(Electron Cyclotron Wave,ECW)沉积位置和驱动电流效率的影响研究.研究结果表明,考虑杂质对等离子体的影响时,随着杂质浓度的增加,ECW沉积径向位置先向等离子体芯部移动然后向边缘移动,电流驱动效率先增加后减小.不考虑杂质对等离子体影响时,ECW沉积位置基本不变,电流驱动效率降低.
作者：
Shi, M. L.;Zheng, P. W.;Yin, L.;He, L. H.;Huang, Q. H.;...
期刊：
Plasma Physics and Controlled Fusion,2022年64(11):115013 ISSN：0741-3335
通讯作者：
P W Zheng
作者机构：
[Zheng, P. W.; Shi, M. L.] Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.;[Huang, Q. H.; Deng, S.; Zheng, P. W.; He, L. H.; Gong, X. Y.; Yin, L.; Zhong, Y. J.] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.;[Huang, Q. H.; Zheng, P. W.; He, L. H.; Gong, X. Y.; Yin, L.] Univ South China, Demonstrat Base Int Sci & Technol Cooperat Nucl E, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[P W Zheng] S;School of Resource Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, People's Republic of China<&wdkj&>School of Nuclear Science and Technology, University of South China, Hengyang, Hunan 421001, People's Republic of China<&wdkj&>Demonstration Base for International Science and Technology Cooperation on Nuclear Energy and Nuclear Safety, University of South China, Hengyang, Hunan 421001, People's Republic of China
关键词：
neoclassical tearing modes;modified Rutherford equation (MRE);Ohkawa-mechanism-dominated current drive (OKCD);electron cyclotron current drive (ECCD)
摘要：
<jats:title>Abstract</jats:title>
<jats:p>This paper reports a numerical study of the 2/1 neoclassical tearing mode (NTM) stabilized by the Ohkawa-mechanism-dominated current drive (OKCD) of electron cyclotron (EC) waves, and the results are compared with those of the traditional Fisch–Boozer mechanism dominated EC current drive (ECCD). The peak values, radial positions and radial widths of the driven current profiles by EC waves are passed to the modified Rutherford equation to study the effect of OKCD/ECCD on the 2/1 NTM. Well-localized current density profiles and large driven current can be achieved for 2/1 NTM stabilization in a low-aspect-ratio tokamak (<jats:italic>R</jats:italic>/<jats:italic>a</jats:italic> ∼ 2.7) by using OKCD. The optimal minimum EC powers are calculated for both OKCD and ECCD to fully stabilize the 2/1 NTM. We compare our results with those of ECCD to stabilize the 2/1 NTM, when the choices of magnetic field strength and gyrotron frequency are such that off-axis deposition on the high-field side is not practical to generate localized current effectively, so that the electron trapping effect is large and important. In this paper, we show that it is better to use lower gyrotron frequencies optimized for the Ohkawa mechanism to obtain a higher current drive efficiency for 2/1 NTM stabilization.</jats:p>
