Aquecimento do plasma por radio frequencia na maquina linear lisa

AUTOR(ES)
DATA DE PUBLICAÇÃO

1986

RESUMO

We show in this work the characteristics of an experimental device assembled in the Instituto de Física, Universidade Federal Flurninense (Linear Mirror Type Machine LISA) to produce Helium plasma by RF and to study its behavior when confined by a magnetic field with mirrors. The plasma was produced by a micro-wave generator of, fRF = 2.45 GHz, PRF = 800 Watts, which can be operated in steady or pulsed state. The plasma parameters were studied as a function of external magnetic field B0 with two differents configurations: 1. large resonance region, 2. small resonance region. The axial and radial magnetic field B0 ,Bz(r, z) and Br(r, z) were mapped for each configuration in order to verify the spatial distribution, particle orbits and energy confinement time according to the energy balance equation dTej/dt = aj ? Tej/tj (j = 1,2) (1) where aj, tj are heating rate and energy confinement time respectively. In steady state, we have Tej = ajtj (2) where Tej is electron temperature and tj is a function of pressure, temperature, magnetic field, electric field, etc. Applying the micro-wave at the electron cyclotron frequency wRF = eB0/meC we measured the electron temperature and density Te, ne, floating potential and plasma potential, VF, Vp and obtained the electric field profile Er, Eq and Ez. Changing the magnetic field distribution (B1, B2), we can compare aj and tj with Tej for the two configurations. Besides the influence of the external magnetic field, B0, in the electron heating of ECRH, it was identified some resonant absorption or mode conversion to Langmuir wave with characteristics of parametric decay, thermalization process (collisions and inverse Bremsstrahlung) and slow ion acoustic mode (w

ASSUNTO(S)

radiofrequencia aquecimento do plasma

ACESSO AO ARTIGO

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