A Two-Crystal Spectrometer for X-Rays of Wave-Length 0.030<λ<0.215A

A two-crystal x-ray spectrometer for use in the wave-length region 0.030<λ<0.215A is described. Transmission and reflection of the x-rays through the body of the crystal, instead of the usual reflection from the surface, is employed. An ionization chamber containing argon at 80 atmospheres, and an FP-54 electrometer tube system is used to measure the intensity of the reflected radiation. A source of short wave-length x-rays, consisting of two specially designed induction coils and a cascade Coolidge tube, is described. Rocking curves in the (1, −1) position at 50 X.U., the K limits of lead and of uranium, and the Kα and Kβ-lines of tungsten were observed for the purpose of calibrating the spectrometer. The resolving power of the instrument with the present crystals is discussed.