Modeling of a hydrogen plasma and its emission spectra in a inductively coupled, cylindrical discharge

Summary form only given, as follows. A cylindrically symmetric model of a steady, moderate pressure, inductively coupled, RF hydrogen plasma discharge is presented in which Maxwell´s equations for the electromagnetic fields are solved self-consistently with the electron diffusion and electron heating equations. The axial extent of the plasma and coil are assumed much larger than their respective radii. A plasma chemistry for the neutral species H and H/sub 2/, and ionic species H/sup +/, H/sub 2//sup +/, and H/sub 3//sup +/ is included with multi-species diffusion for the dominant neutral constituents and ambipolar diffusion for the charged components. A neutral temperature equation accounts for the transfer of energy from the electrons to the neutrals. At the walls, a Langmuir sheath describes the charged particles including secondary emission, and hydrogen recombination on the wall into H/sub 2/ is modeled through a coefficient /spl gamma/. We investigate the changes in the radiative emission from the visible Balmer lines of atomic hydrogen as the power coupling per unit axial length, gas pressure, and /spl gamma/ are varied. In particular, if the H wall recombination rate is large the ratio of the /spl alpha/ to /spl beta/ Balmer line intensities is only a few. On the other hand, if /spl gamma/ is small (as for quartz walls) collisional excitation processes control the emission and the ratio is of order 10 or more.