Integrated plasma scenario analysis for the HL-2M tokamak

Abstract

HL-2M is a new medium-sized tokamak under construction at the Southwestern Institute of Physics, dedicated to supporting the critical physics and engineering issues of ITER and CFETR. Analyzing integrated plasma scenarios is essential for assessing performance metrics and foreseeing physics as well as the envisaged experiments of HL-2M. This paper comprehensively presents the kind of expected discharge regimes (conventional inductive (baseline), hybrid and steady-state) of HL-2M based on the integrated suite of codes METIS. The simulation results show that the central electron temperature of the baseline regime can achieve more than 10 keV by injecting 27 MW of heating power with a plasma current of I p = 3 MA and Greenwald fraction f G = 0.65, with the thermal energy and β N reaching 5 MJ and 2.5, respectively. The hybrid regime with f ni = 80%–90% can be realized at I p = 1–1.4 MA with f G around 0.5, where β N is 2.3–2.5 with H 98(y ,2) = 1.1. Because of the effect of the on-axis NBCD, the hybrid steady state, at I p = 1.0 and 1.2, can be achieved more easily than the steady state regimes with reversed shear, corresponding to β N = 2.6 and 3.4. Such studies show that HL-2M is a flexible tokamak with a significant capacity for generating a broad variety of plasmas as a consequence of the different heating and current drive systems installed.

Development of a high-temporal resolution neutron flux measurement system for the HL-2M tokamak

“…Figure 9 shows the layout of the HTRNFM system, the bismuth germinate (BGO) detector and the NFM systems which include a 235 U fission chamber, a BF 3 counter and a 3 He counter. Both the BF 3 counter and the 3 He counter are about 6.5 m away from the center of the tokamak, while the 235 U fission chamber and the BGO detector are about 11 m away from the center of the tokamak. Cares must be taken that the NFM systems were developed for different neutron yield measurements, i.e., both the 3 He counter and the BF 3 counter are dedicated in low neutron yield measurements, while the 235 U fission chamber in high neutron yield measurements.…”

“…It can be found that the neutron count rate obtained with the HTRNFM system has the same variation trend as that obtained with the 235 U fission chamber, which proves that the HTRNFM system is suitable for high flux neutron measurements. 235 U fission chamber count rate "FC" and 3 He counter count rate " 3 He", (c) BF 3 counter count rate "BF 3 " and 𝛾/X ray integral value of BGO detector signal "BGO", and (d) count rate of the HTRNFM system in the scalar mode "HTRN 𝑆 " and integral value of the HTRNFM system in the Campbell mode "HTRN 𝐶 ". The blue curves correspond to the left 𝑦-axes, while the red curves correspond to the right 𝑦-axes.…”

“…Research on energetic ion confinement behaviors which are of great importance for magnetic confinement fusion plasmas have been intensively performed in the HL-2A tokamak [1], as well as other magnetic confinement devices [2]. Since the HL-2M tokamak [3] has rather higher plasma parameters than those of the HL-2A tokamak [4], it is expected that energetic ion confinement research in HL-2M will give more interesting results. In order to study the energetic ion confinement behaviors in MCF plasmas, the scintillator-based probe for fast-ion losses (FILP) has been developed in many magnetic confinement devices including the HL-2A tokamak [5], the EAST tokamak [6], the Large Helical Device (LHD) [7], etc.…”

“…Figure10. Time traces of (a) plasma current "I 𝑝 " and power of NBI "P NBI ", (b) 235 U fission chamber count rate "FC" and 3 He counter count rate "3 He", (c) BF 3 counter count rate "BF 3 " and 𝛾/X ray integral value of BGO detector signal "BGO", and (d) count rate of the HTRNFM system in the scalar mode "HTRN 𝑆 " and integral value of the HTRNFM system in the Campbell mode "HTRN 𝐶 ". The blue curves correspond to the left 𝑦-axes, while the red curves correspond to the right 𝑦-axes.…”

A phase processor used in terahertz interferometer for tokamak

“…By calculating the phase difference between the reference signal and the detected signal, the measurement of the electron density is got according to the relationship between the phase difference change and the plasma density, namely 𝑛 e = 1.182 × 10 6 𝑓 0 /𝐿 ( 𝑓 and 𝐿 are the working frequency of the interferometer and the length of the electromagnetic wave passing through the plasma, respectively) [6]. The detected signal and reference signal output by terahertz interferometer on HL-2M device [7,8] are 200 kHz [5]. In order to accurately measure the electronic density, effective phase processing technology should be used.…”