Electron density and temperature of gas-temperature-dependent cryoplasma jet

Abstract

A microsize cryoplasma jet was developed and analyzed at plasma gas temperatures ranging from room temperature down to 5 K. Experimental results obtained from optical emission spectroscopy and current–voltage measurements indicate that the average electron density and electron temperature of the cryoplasma jet depend on the gas temperature. In particular, the electron temperature in the cryoplasma starts to decrease rapidly near 60 K from about 13 eV at 60 K to 2 eV at 5 K, while the electron density increases from about 109 to approximately 1012 cm−3 from room temperature to 5 K. This phenomenon induces an increase in the Coulomb interaction between electrons, which can be explained by the virial equation of state.