A Soft X-Ray Spectrometer using a Flow Proportional Counter

Abstract

A soft x‐ray spectrometer operating in the wavelength region of 30–200 A has been built in order to study the electronic properties of metals and alloys. The detector is a flow proportional counter with a 1000 A cellulose nitrate window. The window sets the upper limit of the spectrometer and will transmit only 17% of the radiation at 200 A. By using an aluminized replica grating of 600 lines/mm, the resolution was calculated to be 0.7 A for a wavelength of 64 A. The M_{4, 5} emission spectra of Mo and Nb, and the K emission bands of C and Be, have been investigated. The K emission band of Be had a peak intensity of 475 counts/sec and a peak‐to‐background ratio of 20 to one for a beam current of 4 ma and a potential of 1900 v. The carbon K emission band had a peak intensity of 700 counts/sec with a peak‐to‐background ratio of 30 to one for a beam current of 2 ma and a potential of 2000 v.