NRL-designed berylium window x-ray ionization chamber similar to those used in the early 1960's on the Explorer VII, Vanguard III and Solrad I satellites. The berylium window in this detector was designed to admit x-ray radiation. The charges generated by the impact of the photons on the interior gas then traveled to the oppositely charged anode electrode. Additional collisions of the ions and electrons with filling gas on their way to the electrodes generated more charges and in effect amplified the signal. This artifact is part of a collection of original high-energy detectors from the Naval Research Laboratory (see Catalogue numbers 19880001000-19880017000). It was transferred to NASM in 1987.
This object is on display in Boeing Aviation Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.