Robust, Superhydrophobic Aluminum Fins with Excellent Mechanical Durability and Self-Cleaning Ability.

The self-cleaning ability of superhydrophobic metal surfaces has attracted extensive attention. The preparation of superhydrophobic material using the coating method is a common processing method. In this experiment, aluminum fins were processed by laser etching and perfluorinated two-step coating.

Design of infrared radiation diagnostic calorimeter for the prototype radio frequency driven negative ion source for neutral beam injection.

In order to study the generation and extraction of negative ions for neutral beam injection application, a prototype radio frequency driven negative ion source and the corresponding test bench are under construction at the Institute of Plasma Physics, Chinese Academy of Sciences. A new design of infrared radiation diagnostic calorimeter for testing beam characteristics is put forward. Compared with the conventional calorimeter, the calorimeter adopts the block structure (8 × 28 tungsten hexahedron blocks) and modularization design (4 modules), so it has higher precision and good scalability.

Preliminary design of diagnostic system for negative neutral beam injector at ASIPP.

According to the latest physics design of the China Fusion Engineering Test Reactor (CFETR), two neutral beam injectors (NBIs), which deliver a total of 40 MW in not less than 3600 s with 1 MeV D, are demanded to support current drive and plasma rotation. To minimize the risks and time to provide the CFETR with reliable NBIs, a negative NBI test facility will be developed at the Institute of Plasma Physics, Chinese Academy of Science. Its mission is to understand the characteristics of the RF driven ion source and negative ion generation and extraction and to improve RF efficiency and beam quality.

Structure design and analysis of RF ion source for negative ion source test facility.

A negative ion source acts as a critical part in a neutral beam injector (NBI). A high current ion source is required for the high-power NBI. In this paper, a prototype radio frequency (RF) ion source and its test facility are developed in the Institute of Plasma Physics, Chinese Academy of Sciences, to demonstrate the key technology of the high power negative ion source.

Physics and engineering design of 400 keV H accelerator for negative ion based neutral beam injection system in China.

A research project of the China Fusion Engineering Test Reactor (CFETR) Negative ion-based Neutral Beam Injection (NNBI) prototype has been started in China. The objectives of the CFETR NNBI prototype are to produce a negative hydrogen ion beam of >20 A up to 400 keV for 3600 s and to attain a neutralization efficiency of >50%. In order to identify and optimize the design of the negative ion accelerator, a self-consistent model has been developed to consider all key physics and engineering issues (electric and magnetic fields, background gas flow, beam optics, beam-gas interaction, secondary particle trajectories, power deposition on grids, heat removal design, and mounting pattern).

Development of a core snubber for the neutral beam injector on EAST.

A 4-MW ion source was developed for the neutral beam injector (NBI) on Experimental Advanced Superconducting Tokamak (EAST). Breakdown nevertheless can happen during ion source conditioning and routine operations and is deleterious to the high-power ion source. To protect this ion source, a core snubber was designed to absorb the breakdown energy of the EAST-NBI ion source.

Development and preliminary results of radio frequency ion source.

A radio frequency (RF) ion source was designed and developed for neutral beam injector. A RF driver test bed was used with a RF generator with maximum power of 25 kW with 1 MHz frequency and a matching box. In order to study the characteristic of RF plasma generation, the capacitance in the matching box was adjusted with different cases.

Performance of positive ion based high power ion source of EAST neutral beam injector.

The positive ion based source with a hot cathode based arc chamber and a tetrode accelerator was employed for a neutral beam injector on the experimental advanced superconducting tokamak (EAST). Four ion sources were developed and each ion source has produced 4 MW @ 80 keV hydrogen beam on the test bed. 100 s long pulse operation with modulated beam has also been tested on the test bed.

The R&D progress of 4 MW EAST-NBI high current ion source.

A high current ion source, which consists of the multi-cusp bucket plasma generator and tetrode accelerator with multi-slot apertures, is developed and tested for the Experimental Advanced Superconducting Tokamak neutral beam injector. Three ion sources are tested on the test bed with arc power of 80 kW, beam voltage of 80 keV, and beam power of 4 MW. The arc regulation technology with Langmuir probes is employed for the long pulse operation of ion source, and the long pulse beam of 50 keV @ 15.

First plasma of megawatt high current ion source for neutral beam injector of the experimental advanced superconducting tokamak on the test bed.

High current ion source is the key part of the neutral beam injector. In order to develop the project of 4 MW neutral beam injection for the experimental advanced superconducting tokamak (EAST) on schedule, the megawatt high current ion source is prestudied in the Institute of Plasma Physics in China. In this paper, the megawatt high current ion source test bed and the first plasma are presented.