Recombination of argon in an expanding plasma jet

This paper deals with the behavior of an electron gas in an expanding plasma jet in argon. From the measurements, obtained using a high-quality Thomson-Rayleigh scattering diagnostic, it is shown that the collisional-radiative recombination of argon is small. However, the three-particle recombination plays a determining role in the heating of the electron gas. From the relation between the electron density and the electron temperature in the first part of the expansion, the three-particle recombination coefficient is calculated, which shows good agreement with previous results reported in the literatur

Response of the electron density and temperature to the power interruption measured by Thomson scattering in an inductively coupled plasma

Electron density and temperature measurements during a power interruption of the generator are performed on a 100-MHz flowing-argon inductively coupled plasma. The Thomson scattering setup for measuring the density and temperature is triggered in such a way that temperatures and densities are obtained as a function of time while the power is interrupted. The response of the electron temperature to the power interruption shows a jump downwards within 5 µs, presumably towards the heavy particle temperature. Therefore, the method can be used to determine the heavy particle temperature. Furthermore, insight is obtained as to the behavior of the electron density in the center of the plasma; it increases rather than decreases after the power interruption

Numerical simulation of the response of Li state densities to power interruption in an inductively coupled plasma

The response of Li levels to power interruption in an inductively coupled plasma (ICP) is calcd. by using a time dependent collisional radiative model of the Li system, extended with transport. The input data for the calcns., the electron d., the electron temp., the transport frequency of the ions and the evapn. source are estd. on the basis of expts. The obtained results show a very good agreement with exptl. results when the ionization flow through the system by evapn. and heating of analyte is taken into account. [on SciFinder (R)

Measurements of shock waves using Thomson- and Rayleigh scattering on an expanding plasma

A new combined Thomson and Rayleigh scattering setup is presented. A key problem in developing a Thomson-Rayleigh scattering setup is the level of the unwanted stray light. The level in the new setup is decreased to 10-2 torr Ar, making possible the measurement of neutral densities down to 1020 m-3. The setup is used to measure ne, n0, and Te in an expanding magnetized cascaded arc plasma, which, depending on the operating mode, has electron densities in the range 5 * 1017-1021 m-3, neutral densities in the range 1020-1023 m-3, and electron temps. of 1000-25,000 K. [on SciFinder (R)