Appearance of Chance Coincidence in Attenuation Measurements Carried out by using Coincidence Technique

Main Article Content

Mahmoud A. Elawi
Rasha W. Klaib
Khalid H. Mehdi

Abstract

The appearance of chance coincidence in attenuation measurements using coincidence technique is investigated. A two 3"*3" NaI(Tl) detector coincidence spectrometer with 0.5 μ Ci Na-22 source were used. Two different materials with different forms, namely mixed metallic powders and Fe-sheets are used. The ratio of chance counts to total real coincidences in annihilation peak had ranged between (0.007-0.013) and (0.011-0.036) for the different thicknesses of the two materials mentioned respectively. The coincidence linear attenuation coefficients due to the chance coincidence at 1274keV were 0.1 and 0.38 cm-1 for the two materials assuring the proportionality with energy. When the chance coincidence counts were treated as being "lost" from real coincidences and added again to the latter, no change were observed in attenuation coefficient at annihilation peak from that calculated before taking accidental counts into consideration.

Article Details

How to Cite
Mahmoud A. Elawi, Rasha W. Klaib, & Khalid H. Mehdi. (2022). Appearance of Chance Coincidence in Attenuation Measurements Carried out by using Coincidence Technique. Tikrit Journal of Pure Science, 26(1), 92–95. https://doi.org/10.25130/tjps.v26i1.104
Section
Articles

References

[1] Rossi, B. (1930), Nature, 125.

[2] Lederer, C.M., and Shirley, V.S. (eds). (1978). Table of Isotopes, 7 th edn. Wiley Interscience Publications New York.

[3] Tsoulfanidis, N., (1995). Measurement and Detection of Radiation, 2ndedn, Taylor and Francis.

[4] Elawi, M.A., Mehdi, K.H., Klaib, R.W. (2017), Investigation of gamma-ray attenuation in metallic powders using gamma-gamma coincidence technique, Tikrit Journal for pure science, vol. 22, (12).

[5] Elawi, M.A., Abbas, L.A., Salih, S.A. M., (2017), Use of gamma-gamma coincidence technique in Investigating gamma-ray attenuation at different energies, Tikrit Journal for pure science, vol. 22, (12).

[6] Elawi, M.A., Khalil, K.I., Hamad, D.K. (2017), comparison of gamma-ray attenuation measured by direct and coincidence spectra, Tikrit Journal for pure science, vol. 22, (12).

[7] Knoll, G., (2000), Radiation Detection and Measurement,