Background on Scintillation counter for uranium prospecting, Object ID 1994.0125.37
A scintillation counter is an instrument for detecting and measuring ionizing radiation by using the excitation effect of incident radiation on a scintillator material, and detecting the resultant light pulses. It consists of a scintillator which generates photons of light in response to incident radiation, a sensitive photomultiplier tube which converts the light to an electrical signal and electronics to process this signal. Scintillation counters are widely used in radiation protection, assay of radioactive materials and physics research because they can be made inexpensively yet with good quantum efficiency, and can measure both the intensity and the energy of incident radiation.
For technical details on scintillation counting, see the following reference:
http://www.hamamatsu.com/resources/pdf/etd/PMT_handbook_v3aE-Chapter7.pdf
Detailed description of Object. ID 1994.0125.37
(Some of the accompanying] photographs provided by donor, Prof. Herbert Clark, Rensselaer Polytechnic Institute.)
The object is a scintillation counter by Chatham Electronics, Model SC-102. According to the accompanying Manual of Operation, the SC-102 incorporates a thallium-activated sodium iodide crystal for converting radiation into scintillations of visible light. This crystal is optically coupled to a photomultiplier tube. Specially designed circuits discriminate against spurious noise signals and count the scintillations due to radioactivity so that minute variations in radiation level can be detected by reading the output pointer needle on the instrument. The design of the SC-102 increases its versatility so that it can be used for uranium prospecting, assaying of ore samples in the field, well logging, and oil prospecting.
A gray leatherette-covered case (ca 10 in high x 14 in long x 7 in wide) includes the scintillation counter and probe, a calibration source, an extension cord for the probe, and waist and shoulder carrying straps. The counter is in a kidney-shaped, red plastic housing covered by horizontal cast aluminum face-plate, into which is stuck, vertically, a pistol-handled probe containing a sodium iodide crystal and photomultiplier tube.
Also included is "Manual of Operation" and an Oct. 1951 edition of USAEC & USGS publication "Prospecting for Uranium".
For additional details on the Chatham Electronics Model SC-102 scintillation counter, see Rick Maurer's comprehensive web-based National Radiation Instrument Catalog at:
http://national-radiation-instrument-catalog.com/new_page_94.htm
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