Pages: 346-351

Authors: Ehsan Sadeghi, Mostafa Zahedifar, and Parasto Rezaii

Abstract

Satisfactory discrimination between the neutron and gamma components in a mixed neutron-gamma field is one of the most important objectives of neutron dosimetry. One of the common techniques for estimating gamma and neutron dose components in mixed neutron-gamma fields is the two peak method. This method has been applied using dosimeters such as LiF:Mg,Ti, but in the present work, a ⁶LiF:Mg,Cu,P dosimeter has been used, whose thermoluminescence sensitivity is much higher than the LiF:Mg,Ti dosimeter, and therefore, if appropriate results are achieved, it can drastically reduce the dose estimation threshold. Applicability of ⁶LiF:Mg,Cu,P for estimation of the gamma dose using the two peak method in a mixed thermal neutron-gamma radiation field was studied. The ratio of the area underneath the high temperature thermoluminescence glow peak to dosimetry peak of this phosphor in an Am-Be neutron field is 0.127, while this ratio in a pure gamma ray field of ¹³⁷Cs is 0.039. The calibration curves were obtained by separately irradiating ⁶LiF:Mg,Cu,P chips with known gamma and neutron doses. Results show that ⁶LiF:Mg,Cu,P can be used to estimate the contributions of neutron and gamma doses in a mixed neutron-gamma field by using the two peak method.

Key words: thermoluminescence, ⁶LiF:Mg,Cu,P, dosimetry, two peak method, mixed field, neutron-gamma

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