Phoswich Detector Assembly

General Principles

Each detector assembly in the HEXTE cluster utilizes two types of detectors. The primary function of the instrument (to measure high energy cosmic x-rays) is accomplished via thallium-doped sodium iodide (NaI(Tl)) scintillation crystals which viewed by photomultiplier tubes. In addition, particle detectors are used to reject contaminating events from cosmic ray interactions, and to provide a signal from the calibration source which is used for automatic gain control.

Each detector has a net open area of about 225 cm2 and covers the energy range 15-250 keV, with an intrinsic spectral resolution better than 9 keV at 60 keV. The phoswich detector architecture employed ensures a low background through the efficient shielding of the primary NaI detector crystal by the CsI shield/light guide crystal.


Collimators - Gain Control Detectors - Phototubes - Phoswich - Magnetic Shielding

HEXTE Cluster