Takashi Shoji

A compact gas scintillation proportional counter for ultrasoft x rays

A gas scintillation proportional counter has been developed for measuring ultrasoft fluorescence x rays. This counter is high‐vacuum compatible for connecting to the ICF‐70 flange of a vacuum chamber. A Mylar window of 0.6‐μm thickness and 12‐mm diameter is utilized for the entrance of the ultrasoft x rays. The counter has a large entrance window of approximately 100 mm2 and an energy resolution high enough to separate C Kα and O Kα radiations. This counter is applicable to not only x‐ray fluorescence analysis, but also to fluorescence‐yield extended x‐ray absorption fine structure measurement of ultralow‐Z elements.

Oxygen and Nitrogen Fluorescence EXAFS Measurements by Gas Scintillation Proportional Counters

An ultrahigh vacuum compatible and compact x-ray fluorescence detector of gas scintillation proportional counter type have been developed for measuring fluorescence yield EXAFS of ultralow-Z elements. Fluorescence yield EXAFS spectra were obtained above the N and 0 K-edges of Si3N4 and Sio2 films for the first time by using this newly developed detector.