A mercuric detector system for X-ray astronomy.  2.  Results from flight tests of a balloon borne instrument

Vallerga, J.; Vanderspek, R. K.; Ricker, G. R.

A mercuric detector system for X-ray astronomy. 2. Results from flight tests of a balloon borne instrument

To establish the expected sensitivity of a new hard X-ray telescope design, an experiment was conducted to measure the background counting rate at balloon altitudes (40 km) of mercuric iodide, a room temperature solid state X-ray detector. The prototype detector consisted of two thin mercuric iodide (HgI2) detectors surrounded by a large bismuth germanate (Bi4Ge3O12) scintillator operated in anticoincidence. The bismuth germanate shield vetoed most of the background counting rate induced by atmospheric gamma-rays, neutrons and cosmic rays. A balloon-borne gondola containing a prototype detector assembly was designed, constructed and flown twice in the spring of 1982 from Palestine, Texas. The second flight of this instrument established a differential background counting rate of 4.2 O.7 x 10-5 counts/sec cm keV over the energy range of 40 to 80 keV. This measurement was within 50% of the predicted value. The measured rate is approx 5 times lower than previously achieved in shielded NaI/CsI or Ge systems operating in the same energy range. The prediction was based on a Monte Carlo simulation of the detector assembly in the radiation environment at float altitude.

Document ID

19840008027

Acquisition Source

Legacy CDMS

Document Type

Contractor Report (CR)

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Date Acquired

September 4, 2013

Publication Date

January 1, 1982

Subject Category

Report/Patent Number

Accession Number

84N16095

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Public

Work of the US Gov. Public Use Permitted.

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