2017/09/20 by Sergey Averkin, Averkin, Sergey N.
Engineering · Physics and Astronomy · #FOS: Physical sciences #Magnetic confinement fusion research #Particle accelerators and beam dynamics #Plasma Diagnostics and Applications #Plasma Physics (physics.plasm-ph)
paper · pdf · doi:10.48550/arxiv.1709.07071
openalex publication_date 2017/09/20 · openalex created_date 2022/09/02 · openalex updated_date 2026/07/28
A Global Enhanced Vibrational Kinetic (GEVKM) model is presented for a new\nHigh Current Negative Hydrogen Ion Source (HCNHIS) developed by Busek Co. Inc.\nand Worcester Polytechnic Institute. The HCNHIS consists of a high-pressure\nradio-frequency discharge (RFD) chamber where high-lying vibrational states of\nthe hydrogen molecules are produced, a bypass system, a nozzle, and a\nlow-pressure negative hydrogen ion production region where \H- are\ngenerated by the dissociative attachment of low energy electrons to\nrovibrationally excited hydrogen molecules. The GEVKM is developed from moment\nequations for multi-temperature chemically reacting plasmas derived from the\nWang Chang-Uhlenbeck equations for a cylindrical geometry of an inductively\ncoupled RFD chamber. The species included into the model are \H(n),\nn=0-3, \H2(v), v=0-14, \H+, \H2+, \H3+,\n\H-, and e. The volume-averaged steady-state continuity equations\ncoupled with the electron energy equation, the total energy equation and heat\ntransfer to the chamber walls are solved simultaneously to obtain the\nvolume-averaged number densities of the plasma components, the electron,\nheavy-particle and wall temperatures. The GEVKM is supplemented by a\ncomprehensive set of surface and volumetric chemical processes governing\nvibrational and ionization kinetics of hydrogen plasmas. Analytic boundary\nconditions developed for the flow in the bypass tubes and in the nozzle take\ninto account rarefaction effects and are validated by comparing pressures\npredictions in the RFD chamber with the pressure measurements. The GEVKM is\nverified and validated in the wide range of pressures and absorbed powers of\ndifferent plasma reactors and is used in a parametric investigation of the RFD\nchamber of the HCNHIS with hydrogen inlet flow rates 5-1000 sccm and absorbed\npowers 200-1000 W.\n