A diagnostic method for both plasma ion and electron temperatures under simultaneous incidence of charge-exchange particles and x rays into a semiconductor detector array.

An idea for using semiconductor detectors to simultaneously observe both plasma ion T[sub i] and electron T[sub e] temperatures is proposed. The idea is also experimentally verified in tandem-mirror plasma shots. This method is developed on the basis of an alternative "positive" use of a semiconductor "dead layer" as an energy-analysis filter. Filtering dependence of charge-exchange neutral particles from plasmas on the thickness of a thin (on the order of nm thick) SiO[sub 2] layer is employed for analyzing T[sub i] in the range from hundreds to thousands of eV. Even under the conditions of simultaneous incidence of such particles and x rays into semiconductor detectors, the different dependence on their penetration lengths and deposition depths in semiconductor materials makes it possible to distinguish particles (for T[sub i]) from x rays (for T[sub e]). In this letter, proof-of-principle plasma experiments for the proposed idea are carried out to verify the availability of this concept of distinguishing and identifying each value of T[sub i] and T[sub e] by the use of various thin filtering materials prior to the use of thinner dead layers. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]