Subjects: Nuclear Science and Technology >> Nuclear Science and Technology submitted time 2024-04-24
Abstract: [Background]: RF power source is an important part of NNBI power system. [Purpose]: It provides RF current for RF ion source to generate plasma and maintain stable discharge. [Methods]: According to the design index, the design structure of the all-solid-state power amplifier is proposed, and the design and analysis of the RF channel buffer amplifier, pre-push amplifier, power amplifier, power synthesizer, output matching and filtering are carried out. [Results]: Finally, 150kW RF plasma discharge is realized. [Conclusions]: This circuit structure is feasible on RF ion source discharging.
Subjects: Physics >> Nuclear Physics submitted time 2024-03-27
Abstract: Background: The propagation and power deposition process of ion cyclotron waves in plasma is the key to ICRH.
Purpose: The purpose of this study is to evaluate the effect of single absorption assumption and non-single absorption assumption on ion cyclotron wave coupling and heating in the EAST.
Methods: Under different antenna current phases, the simulation results of the EAST 3D full vacuum chamber ICRH program and the 1/4 vacuum chamber ICRH program were compared.
Results: When the antenna current phase is (0 π 0 π), there is a significant difference between the simulation results of the two models.
Conclusion: The ion cyclotron wave propagating multiple times in the toroidal direction is the main reason for the difference in results. For fusion devices, the applicability of the single absorption assumption needs further systematic research.
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics Subjects: Physics >> Physics of Gases, Plasmas, and Electric Discharges submitted time 2017-11-27
Abstract: An important feature of China Fusion Engineering Test Reactor(CFETR) project is represented by the additional heating obtained from the injection of neutral beams based on accelerated negative ions. For the neutral beams based on negative ions, the most important measurements are beam uniformity, beamlet divergence and stripping losses. According to the CFETR requirement, the maximum allowed beam divergence angle and beam non-uniformity are 6 mrad and ±10%,respectively. As 1D carbon tiles have large ratio between perpendicular conductivity and parallel conductivity and high stability, they can be used for beam uniformity and beamlet divergence measurement. This paper presents the investigation of the influence on the response of 1D carbon tile having the thermal characteristics and features of some dedicated diagnostics. Simulations show that it will be possible to verify experimentally whether the beam meets the requirement about the maximum allowed value. This work lays a foundation for design and application of high precision beam diagnostic targets.
Peer Review Status:Awaiting Review
Subjects: Physics >> Nuclear Physics submitted time 2017-11-27
Abstract: Neutral beam injection has been recognized as one of the most effective means for plasma heating.According to the research plan of the EAST physics experiment, two sets of neutral beam injector were built and operational in 2014. The paper presents the development of beam diagnosis system for EAST neutral beam injector (NBI) and the latest experiment results obtained on the test-stand and EAST-NBI-1 and 2. The results show that the optimal divergence angle is (0.62°, 1.57°) and the full energy particle is up to 77%. They indicate that EAST NBI work properly and all targets reach or almost reach the design targets. All these lay a solid foundation for the achievement of high quality plasma heating for EAST.
Peer Review Status:Awaiting Review
Subjects: Physics >> Nuclear Physics Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics submitted time 2017-03-02
Abstract:The gyrotron is the most important device in the ECRH system. The cathode power supply is one of the most important ancillary devices for gyrotron. Some interesting transient phenomena about the cathode voltage and the cathode current was found in the gyrotron operation. In order to explain these phenomena, an equivalent model of the magnetron injection gun was proposed. The equivalent circuit is composed of parallel resistors and capacitors, and it can explain the test results very well.
Peer Review Status:Awaiting Review