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Application
The QCD1 source can be used for calibrating high resolution
gamma-ray spectrometers where a solid source with minimal
self-absorption is required. The energy range covered is 88-1836keV.
Construction
The QCD1 source is prepared by dispensing an accurately weighed
aliquot of mixed radionuclide solution onto a polyester tape
0.06mm thick. The aliquot is dried in an atmosphere of hydrogen
sulphide to prevent volatilization of mercury, and then covered
with a second layer of tape. The active deposit is approximately
5 mm in diameter. The tape is attached to a 1mm thick aluminium
annulus of inner diameter 38mm and outer diameter 54mm. The
source is constructed of thin polyester tape to minimise self-absorption
of the gamma-rays and should be handled carefully by its aluminium
ring using rubber-tipped forceps.
The radioactive material is incorporated in a plastic layer,
10mm in diameter and 0.2mm thick. The plastic layer is covered
on each side by a paper label, 0.15mm thick, and the assembly
is heat sealed between 0.125mm thick plastic foils. The foils
are mounted in a ring, 54mm in diameter, 3mm thick (drawing
VZ-1159). |
