THEORETICAL INVESTIGATION OF ELECTRON-TEMPERATURE VARIATION ACROSS MAGNETIC FILTER IN A NEGATIVE-ION SOURCE

Electron temperature variation over the magnetic filter region and the extraction region is investigated theoretically. We assume q(x)/{(5/2 )T Gamma(x)}=beta between heat flux q(x) and electron flux Gamma(x), w here beta is a ratio of the heat flux to the enthalpy flux and T is th e electron temperature. Terms of diamagnetic drift in the expressions of the flux and heat flux are important in obtaining temperature T(x) that agrees with Haas et al.'s experimental results. Electron loss alo ng the magnetic field is important in determining the exponential depe ndence of the electron number density and temperature on 41. Flux inve rsion is attributed to the negative flux due to the electric field. (C ) 1996 American Institute of Physics.