Search

Temporal distribution of the H atom and H2 densities in a pulsed microwave hydrogen plasmas has been measured simultaneously by two-photon absorption laser-induced fluorescence (TALIF). The measurement of the H-atom absolute density obtained by NO2 titration in a flow tube reactor shows that the density of H2 could be determined by the measured effective lifetime of the TALIF signal via the quenching equation. The H-atom density of about 1.5×1015cm-3 in both pulsed and stationary phases does not obviously change. It is found that the gas temperature volume effect plays an important role in governing the distributions of the H-atom density and it is mole fraction. The calculated gas temperature is in good consistent with the rotational temperature of H2 measured by optical emission spectroscopy in pulsed phase.

The former Director of the Southwestern Institute of Physics, Academician Li Zengwu had suggested to the Chinese Government to promote the Nuclear Fusion Research in 1955. In the beginning of 1958, the research of nuclear fusion as future energy resources had been set up as the Fourteenth Division of China Atomic Energy Science Institute in Beijing and the Physics Institute Academy Sinica in Beijing. At the end of 1958, the East-northern Technique Physics Institute in Ha-re-bin was set up as the first institute engaged in nuclear fusion in China and then the Southwestern Institute of Physics was founded in 1965. At the beginning of this Institute, the θ-pinch, Mirror and Tokamak Research were carried on in parallel. Since 1985, the spin-off of fusion technology has been looked as an important field to make contribution to national economics and fusion effort was concentrated on Tokamak at the same time. The HL Tokamak is a general name of fusion project being carried on in Southwestern Institute of Physics, China National Nuclear Corporation. Related fusion technologies are ongoing simultaneously. The outline of HL Tokamak project and the highlights of experimental results obtained on HL-1 and HL-1M are given in this paper. In addition, the fusion efforts made important contributions to a variety of areas. Applications of fusion spin-off technologies, particularly of plasma technologies, are also described briefly in this paper.

The destabilization of the poloidal rotation for the species of ions with the poloidally inhomogeneous sources or sinks is studied in multiple ion species tokamak plasmas. Based on the fluid equations, the evolution equation of the poloidal ion rotation speed is derived analytically. The magnitude of the inhomogeneous sources or sinks needed to destabilize the rotation is shown to be proportional to the ion density. It is suggested that the poloidal plasma rotation can be generated by destabilizing the rotation of the minority ions.

In a relativistic electron cyclotron maser with an axisymmetrical quasioptical cavity of oblique rotation at arbitrary angle, the rotating angle has a great influence on beam-wave interaction. Two different physical mechanisms are found with the rotating angle ranging from 0° to 90°. One is cyclotron auto-resonance maser regime for small angle, with small optimized external magnetic field; the other is electron cyclotron resonance maser regime for large angle, with comparatively large optimized magnetic field.

The particle confinement property of LHCD (lower hybrid current drive) plasma on the HL-1 tokamak is mainly affected by the line-averaged density of electrons (ne). With ne < 2.0 × 1013 cm-3, the particle confinement time (τp) is improved with the suppression of Hα(Dα) fluctuation at the edge, and tends to increase with the power PLH. The peak of τp appears near the critical density (1.0×1013 cm-3). These results are not influenced by the current drive directions.

A new approach is presented to produce core plasma poloidal rotation during electron cyclotron resonance heating (ECRH) in Tokamaks. The physical mechanism employed here is as follows:in a Tokamak plasma with high power ECRH, the resonance particle localization causes poloidal electric field, which consequently induce a poloidally asymmetric ion profile. This kind of poloidal ion accumulation would overwhelm the damping of poloidal rotation from the magnetic pumping, and make the plasma spin up poloidally. Based on the fluid equations and the drift kinetic equation, we have derived the criterion of plasma spin up in the collisionless region. It is shown that the core plasma poloidal rotation can be generated by ECRH in the practical rf power level.

A new plasma maser scheme,the ion-channel electron cyclotron maser (ICECM) is proposed.By making use of the three-dimensional fluid theory,the dispersion relation of the ICECM with circular orbit electron beam is derived.An ion electrostatic gyro-penitron mode is found,and the growth rate of this new mode is obtained by numerical calculation.