Engineering prototype for an event analyzer that formed part of the assembly of one (S056; Cat #19840408000) of the three X-ray telescopes that were flown on the Apollo Telescope Mount (ATM)on Skylab. This analyzer (X-REA), built by James E. Milligan and his staff at Marshall, comprises a proportional counter system with beryllium and aluminum windows. The instrument, which contained its own amplifier and preamplifier, also included a pulse height analyzer, rate meter and activity history plotter. It was transferred to NASM from NASA's Marshall Space Flight Center in 1986.
This object is on display in James S. McDonnell Space Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.