Gamma-ray energy

Gamma spectroscopy is a radiochemistry measurement method that determines the energy and count rate of gamma rays emitted by radioactive substances. Gamma spectroscopy is an extremely important measurement. A detailed analysis of the gamma ray energy spectrum is used to determine the identity and quantity of gamma emitters present in a material. 

A 3.5 ml portion in a 4 ml polyethylene vial was irradiated for 5 min. Another portion, 3.0 ml in a 3.5 ml silica vial, was irradiated for 3 d. After the short irradiation, 3 ml of the irradiated solution were transferred into an activity-free vial and submitted to y-ray spectrometry with a Ge(Ii) detector coupled to a 4000-channel analyser. After the long irradiation, the sample was allowed to cool for 3 d, then the surface of the silica ampoule was cleaned with dilute nitric acid and the sealed ampoule was placed in the counter (the background activity of the ampoule was negligible). Gamma-ray energy and the areas under peaks were calculated by computer. To determine the half-fives of the nuclides produced, the counting was repeated at appropriate intervals. 

Figure 10. Detector efficiency as a function of gamma-ray energy for an 8-cm.3 (Ge(Li)) detector (samples in aluminum cans). The efficiency of the 18-cm.s detector increases in proportion to the surface area...

Fig. 1.3. (a) The gamma-ray energy spectrum for the three-photon decay of... 

Fig. 1.5. Schematic of a gamma-ray energy spectrometer for Doppler broadening studies. The signal from the detector pre-amp is processed by spectroscopy and biassed amplifiers (SA and BA respectively) before being recorded in the multichannel analyser (MCA).

These counting efficiencies are determined for a series of sample volumes. Curves of counting efficiency as functions of gamma-ray energy are drawn... 

Germanium detector calibration as function of sample volume and gamma-ray energy... 

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