Upgrade of plasma density feedback control systemin HT-7 tokamak

The HT-7 is a superconducting tokamak in China used to make researches on the controlled nuclear fusion as a national project for the fusion research. The plasma density feedback control subsystem is the one of the subsystems of the distributed control system in HT-7 tokamak (HT7DCS). The main function of the subsystem is to control the plasma density on real-time. For this reason, the real-time capability and good stability are the most significant factors, which will influence the control results. Since the former plasma density feedback control system (FPDFCS) based on Windows operation system could not fulfill such requirements well, a new subsystem has to be developed. The paper describes the upgrade of the plasma density feedback control system (UPDFCS), based on the dual operation system (Windows and Linux), in detail.     

A Cascaded Discharge plasma—Adsorbent Technique for Engine Exhaust Treatment

A cascaded system of electrical discharges(non-thermal plasma)and adsorption process was investigated for the removal of oxides of Nitrogen(NOx) and total hydrocarbons (THC) from an actual diesel engine exhaust.The non-thermal plasma and adsorption processes were separately studied first and then the casecaded procxess was studied.In this study,different types of adsorbents were used.The NOx removal efficiency processes and the removal efficiency was found almost invariant in time.When associated by plasma,among the adsorbents studied.Activated charcoal and MS-13X were more effective for NOx and THC removal respectively.The experiments were conducted at no load and at 50% load conditions.The plasma reactor was kept at room temperature throughout the experiment,while the temperature of the adsorbent reactor was varied.A relative comparison of adsorbents was discussed at the end.     

A New Waste Disposal Technology—plasma arc Pyrolysis System

This paper introduces a new waste disposal technology with plasma arc.Being different from conventional combustion or burning such as incineration,it is based on a process called controlled pyrolysis-thermal destruction and recovery process.It has four advantages,they are completely safe,clean,high-energy synthesis gas,non-toxic vitrified slag and metal.     

A Novel Vacuum System Control Strategy for High Intensity D–T Fusion Neutron Generator

High intensity D–T fusion neutron generator (HINEG) is a high voltage accelerator-based D–T fusion neutron facility, which provides a significant platform for nuclear technology researches. The steady operation of HINEG vacuum system is enormously significant for its beam quality. In this paper, in order to eliminate the drawbacks and disadvantages caused by the time delay element in vacuum system, a gain adaptive compensation control strategy was proposed for vacuum system. In accordance with vacuum-pumping mechanism, the vacuum dynamic equilibrium equation was transformed from the time domain to the complex frequency domain by means of Laplace transformation, and the system transfer function in vacuum pumping process was derived. The experimental results analyses showed that the overshoot and settling time are eliminated effectively with this gain adaptive compensation control algorithm, which indicated that the system self-regulation and anti-interference performances were greatly improved.     

A VMEbus interface for multi—detector trigger and control system

MUSE（MUltiplicity SElector)is the trigger and control system of CHIMERA,a 4π charged particles detector.Initialization of MUSE can be performed via VMEbus.This paper describes the design of VMEbus interface and functional module in muse,and briefs an application of MUSE.     

Three—dimensional Periodic and Fractal Precipitation in Metal Ion—Deoxycholate System： A Model for Gallstone Formation

It was recently suggested that the periodic and fractal precipitaion of calcium salts and proteins in cholesterol gallstonesis closely related to the process of stone formation.The present study is to mimic the process of gallstone growth in vitro.We demonstrate for the first time that a three-dimensional structure of periodic rings (Liesegang ring)and/or fractal patterns can be produced by metal ion and deoxycholate precipitaiton which are similar to gallstones.Precipitation in a periodic pattern occurs more often than in a fractal structure,Using X-ray diffraction.polarized light microscope,Fourier transform-infrared(FT-IR) ,and extended X-ray absorption fine structure(EXAFS),we studied the pattern formation mechanisms of both types of structure .The results indicate that the rate of nucleation in the crystal growth is a crucial element of affect the pattern formation.The pattern selection between periodic and fractal type depends on the crystal growth speed and the rate of nucleation.