Yuanzhe Zhao

Effects of Armature Characteristics on Armature-Rail Contact Performance

Armature-rail contact performance determines contact resistance between the armature and rail in electromagnetic launch, and the contact resistance directly affects the efficiency of the launch system. Besides, poor contact performance between the armature and rail will results in erosion, gouging, and other issues in launch. These issues will induce surface damage for the rail, and affect the repetitive launch. So it’s important to improve the armature-rail contact performance. As the characteristics of the rail are relatively stationary in the system, more research was done on the effect of armature characteristics (such as material, shape of the contact, thickness of the neck, and structure of the empennage). In this paper, method of combining ANSYS and pressure test paper was used to study the armature-rail contact performance. The dynamic changing process of the armature-rail contact state was observed by ANSYS, and the final contact state in the case of prepressed experiment was observed by pressure test paper and pressure analysis system. Results from ANSYS and pressure test paper would be comparative analyzed in order to get a more accurate conclusion in the condition of actual experiments. The conclusion of this paper is instructive on optimizing armature design and improving armature-rail contact performance.

Design and Preliminary Results of Matching Network for MW Scale High Current RF Ion Source

Abstract The RF ion source is the most promising ion source, which can be operated with steady state. When the Radio Frequency (RF) ion source works, the key point is how to transmit and couple the RF power to the plasma with the RF power transmission unit. In this technical note, the principle of RF matching network was analyzed and designed. The RF power transmission unit was tested on RF ion source test bed. Based on the experimental data, the function of each components of impedance-matching network is analyzed and optimized. The results show that matching network can keep high RF coupling efficiency with variable plasma parameters and decreases the reflected RF power.

RF, Disruption, and Thermal Stress Analyses of EAST I and B Port Antennas

Chinese Academy of Sciences Institute of Plasma Physics and Massachusetts Institute of Technology Plasma Science and Fusion Center have been collaborating on experimental advanced superconducting tokamak (EAST). Presented in this paper are RF, disruption, and thermal stress analyses of EAST antennas. Analyzed are I port four-strap and B port 2 × 2 strap antennas, which are currently installed on EAST. As for RF analysis, scattering parameters are checked to make sure that the antennas are loaded, and then electric field parallel to magnetic field are checked to find out if they are below the permissible level. As for disruption analysis, mechanical stresses for both straps with the support box and Faraday screen are obtained. As for thermal stress analysis, temperature and thermal stress for a typical strap and a Faraday tube were presented. All analyses were performed by COMSOL commercial finite-element analysis software package version 5 or 5.2.