Positions Open in the Field of Plasma and Fusion

Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), one of the most important Laboratories on magnetically confined fusion in China and the Nuclear Fusion Research Center of the World Laboratory, is searching for 5 senior and 10 junior scientists of plasma and fusion in the following superconducting tokamak research areas: theory and simulation, diverter and edge physics, plasma diagnostics, electron cyclotron resonant heating, ion cyclotron resonant heating, lower hybrid wave, neutral beam injection, reactor design, fusion material, superconducting engineering.     

Positions Open in the Field of Plasma and Fusion

Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), one of the most important laboratories on magnetically confined fusion in China and the Nuclear Fusion Research Center of the World Laboratory, is searching for 5 senior and 10 junior scientists of plasma and fusion in the following superconducting tokamak research areas: theory and simulation, diverter and edge physics, plasma     

Positions Open in the Field of Plasma and Fusion

Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), one of the most important laboratories on magnetically confined fusion in China and the Nuclear Fusion Research Center of the World Laboratory, is searching for 5 senior and 10 junior scientists of plasma and fusion in the following superconducting tokamak research areas: theory and simulation, diverter and edge physics, plasma diagnostics, electron cyclotron resonant heating, ion cyclotron resonant heating, lower hybrid wave, neutral beam injection, reactor design, fusion material, superconducting engineering.     

Positions Open in the Field of Plasma and Fusion

Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), one of the most important laboratories on magnetically confined fusion in China and the Nuclear Fusion Research Center of the World Laboratory, is searching for 5 senior and 10 junior scientists of plasma and fusion in the following superconducting tokamak research areas: theory and simulation, diverter and edge physics, plasma diagnostics, electron cyclotron resonant heating, ion cyclotron resonant heating, lower hybrid wave, neutral beam injection, reactor design, fusion material, superconducting engineering.     

Calculation of ρR-parameter and Energy Gain for Aneutronic Fusion in Degenerate P–11 B Plasma

Aneutronic fusion reactions are more safe and clean than the other reactions. One of the important candidate for these reactions is P–¹¹ B. This reaction in characteristic conditions creates degenerate plasma. In a Fermi-degenerate plasma, the electronic stopping of a slow ion is smaller than given by the classical formula, because some transitions between the electron states are forbidden. The bremsstrahlung losses are then smaller, so that the nuclear burning of an aneutronic fuel is more efficient. Practical obstacles in this regime that must be overcome before net energy can be realized include the compression of the fuel to an ultra dense state and the creation of a hot spot. In this paper, ρR parameter (Lawson’s criterion) and energy gain for P–¹¹ B are given.     

Numerical Studies of Plasma Rotation in HL-1M Tokamak

The discovery of the H-mode provides the efficient way for improving energy confinement in current Tokamak experiments and for optimizing design of next generation Tokamak devices. The studies of L-H transition mechanism were developed from phenomenology to self-consistency theory progressively. The L-H-VH mode     

Experimental Investigation of Processes Occurring in the Plasma of a Cesium–Barium Tasitron

The results of measurements of plasma parameters in different regions of a nonstationary discharge in a cesium–barium tasitron with 1-sec time resolution are presented. Data analysis made it possible to determine the quenching mechanism of a discharge in a three-electrode system with large-structure grid. 7 figures, 12 references.     

Plasma Radiofrequency Discharges as Cleaning Technique for the Removal of C–W Coatings

Erosion of materials by chemical and physical sputtering is one of the most concern of plasma wall interaction in tokamaks. In divertor ITER-like tokamaks, where carbon and tungsten are planned to be used, hydrogenated C–W mixed compounds are expected to form by erosion, transport and re-deposition processes. The selection of these materials as divertor components involves lifetime and safety issues due to tritium retention in carbon co-deposits. In this paper a cleaning technique based on RF (13.56 MHz) capacitively coupled H₂/Ar plasmas has been used to remove C–W mixed materials from test specimens. The dependence of the removal rate on the H₂/Ar ratio and on the plasma pressure has been investigated by X-ray photoelectron spectroscopy, atomic force microscopy, profilometry as regards the solid phase and by Langmuir probe and optical emission spectroscopy as regards the plasma phase. The best result has been obtained with a H₂/Ar ratio of 10/90 at a pressure of 1 Pa. An explanation based on a synergistic effect between physical sputtering due to energetic ions and chemical etching due to radicals, together with the pressure dependence of the ion energy distribution function, is given.     

Energy Dependence of the Fusion Barrier for Heavy Nuclear Systems

The dynamical behavior of the fusion potential barrier for heavy nuclear systems is studied by meansof the improved quantum molecular dynamics model. It is found that the fusion potential barrierexperienced in a realistic fusion process (the dynamic fusion potential barrier) reduces with decrease ofincident energies. The up-and low-limit of the dynamic fusion potential barrier approach to the diabaticand adiabatic fusion barrier, respectively. The reason for the energy dependence of the dynamic barrier isexplored. With this approach the extra-push energy for above-the-barrier fusions of heavy nuclei can beobtained self-consistently.     

Studies on the Characteristic of Zirconium–Tritium Reaction

The p–c–T curves of tritium absorption and desorption of zirconium were measured using the method of step equilibrium by stepping up the tritium quantity on an experimental apparatus of metal hydride. The p–c–T curves for tritium have one plateau at temperature range from 450 to 500°C and two plateaus at temperature above 600°C. The thermodynamic parameters of the different phases were determined according to the van’t Hoff equation. The hysteresis effect was observed in reversible process of tritium absorption and desorption of zirconium on our experimental condition. The tritium absorption behavior by zirconium in the temperature range from 450 to 620°C and desorption behavior of zirconium in the temperature range from 775 to 875°C have been investigated. A method of the reaction rate analysis was proposed and examined for determining the rate constant. The apparent activation energy obtained by this analysis for the absorption and the desorption were (−16.8 ± 0.8) kJ·mol⁻¹ and (57.7 ± 1.6) kJ·mol⁻¹, respectively.     

The Energy Dependence of the Fusion Barrier for Heavy Nuclear Systems

Being encouraged by the synthesis of superheavy elements, the investigation on fusion mechanism atlow energies has recently received a great attention theoretically and experimentally. However, up to now there is no consensus for the mechanism of the comp…     

The Progress of a Microbeam Facility in the Institute of Plasma Physics

The progress of a microbeam facility in the institute of Plasma Physics was discussed in this paper.This kind of equipment can supply single-particle beam which may be implanted into cells in micrometer-radius and measured by a new outstanding detector among global microbeam systems.Measurements by some plain targets showed that the highest current after the accelerator tube can be larger than 20μA ,the H2^ current before the second bending magnet is near 0.9μA ,the current after the second bending magnet is near 0.8μA,and the current of the beam line(after a 2-mm diameter aperture)is near 0.25nA which is enough for the single-particle microbeam experiment.It took scientists 3 months to do their microbeam experiment after setting up the qccelerator beam line and get the microbeam from this equipment.Two pre0collimators were installed between the 2-mm diameter aperture and the collimator to survey the beam.Tracks on the CR39 film ectched in the solution of NaOH showed that the beam can go through the collimator including a 10μm diameter aperture and the 3.5μm thick vacuum sealing film(Mylar).A new method,which is called optimization of the beam quality,was put forward in this paper,in order to get smaller diameter of beam-spot in microbeam system.     

(3He,xn) Reaction Cross-Section Calculations for the Structural Fusion Material 181Ta in the Energy Range of 14–75 MeV

The theoretical neutron-production cross-sections produced by ¹⁸¹Ta(³He,xn)^184?xRe reactions (x = 1–7) for structural fusion material ¹⁸¹Ta in ³He-induced reactions have been performed in the incident ³He energy range of 14–75 MeV. Reaction cross-sections, based on theoretical pre-equilibrium nuclear reaction models, have been calculated theoretically by means of the TALYS 1.6 two component exciton, EMPIRE 3.1 exciton, ALICE/ASH geometry dependent hybrid (GDH) and ALICE/ASH hybrid models. The neutron-production cross-section results of the models have been compared with the each other and against the experimental nuclear reaction data (EXFOR). Except the ¹⁸¹Ta(³He,2n)¹⁸²Re and ¹⁸¹Ta(³He,7n)¹⁷⁷Re reactions, the ALICE/ASH cross-section calculations show generally agreement with the experimental values for all reactions used in this study. The ALICE/ASH–GDH model can be suggested, if the experimental data are unavailable or are improbably to be produced because of the experimental troubles.     

Application of the Multi-Electrode in the Degradation of Alizarin Red Induced by Glow Discharge Plasma

This paper presents a novel set-up to be used in the degradation of dye, Various influencing factors, such as the voltage, the number of the anodes, and the catalytic action of Fe^2＋, were examined. Chemical oxygen demand （COD）, ultraviolet （UV）, FTIR absorption spectra, and atomic force microscopy （AFM） were used to monitor the degradation process. The results showed that the efficiency of degradation is raised by increasing the applied voltage, and is further improved when two or three anodes are used. Moreover, the use of Fe^2＋ ion can promote the degradation reaction and shorten the degradation time. So the multi-electrode instrument is more efficient in degrading the dye and should be further studied.     

Numerical Design of Megawatt Gyrotron with 120 GHz Frequency and 50% Efficiency for Plasma Fusion Application

The design of 120 GHz, 1 MW gyrotron for plasma fusion application is presented in this paper. The mode selection is carried out considering the aim of minimum mode competition, minimum cavity wall heating, etc. On the basis of the selected operating mode, the interaction cavity design and beam-wave interaction computation are carried out by using the PIC code. The design of triode type Magnetron Injection Gun (MIG) is also presented. Trajectory code EGUN, synthesis code MIGSYN and data analysis code MIGANS are used in the MIG designing. Further, the design of MIG is also validated by using the another trajectory code TRAK. The design results of beam dumping system (collector) and RF window are also presented. Depressed collector is designed to enhance the overall tube efficiency. The design study confirms >1 MW output power with tube efficiency around 50% (with collector efficiency).     

The Experiment of Obtaining Micron Beam in the Single-Particle Microbeam Facility of the Institute of Plasma Physics

The Experiments, methods and results of obtaining micron beam in the Microbeam Facility of the Institute of Plasma Physics were discussed in this paper. The H2^ beam was accelerated by the Van de Graa/f electrostatic accelerator, and the collimator at the end of the beam line is a 60μm thick stainless steel chip. And as a result, particle tracks on the solid track probes (CR39 film) etched in the solution of NaOH showed that the beam can go through the collimator with a small aperure (2000, 300, 55, 30, or 10μm) and 3.5μm thick vacuum film(Mylar). Besides the CR39 method, the beam was measured by an energy spectrum detector after the 10μm diameter aperture and the 3.5 μm thick vacuum film too.     

Nuclear Spin-Polarized Proton and 11B Fuel for Fusion Reactors: Advantages of Double Polarization in the 11 B(p, α)8 Be * Fusion Reaction

A previously developed general formalism has been used to calculate the yield and the angular distributions of outgoing particles for fusion reactions when the projectile and target nuclei are both polarized. The case of D–³He is compared with earlier calculations and experiments and a new study for the case of fully polarized protons and ¹¹B in the ¹¹ B(p, α)⁸ Be ^* reaction is presented. The conditions which produce a gain in the yield and the angular distributions which affect the production of fusion energy are presented.