A comparison of cross sections for Selenium -73 radioisotopes produced by accelerators and reactors

Abstract

Background: Selenium-73 with half- life of 7.15 hour emits β⁺ in nature and has six stable isotopes which are ( ⁷⁴Se,⁷⁶Se,⁷⁷Se,⁷⁸Se,⁸⁰Se and ⁸²Se ). Selenium-73 has many applications in technology and radioselenium compounds of metallic have found various applications in medicine.

Objective:  To make a comparison between different reactions that produced cross sections of Se-73 radioisotopes.

Subjects and methods: The feasibility of the production of Selenium -73 via various nuclear reactions was investigated. Excitation functions of ⁷³Se production by the reactions of ⁷⁵As (p,3n), ¹⁶⁹Tm( d,x), ⁷⁴Se, ^natSe, ^natBr (p,x) , ⁷⁵As (d,4n), ^natGe (³He,x), ⁷⁰Ge (α, n), and ⁷²Ge (α, 3n) and neutron capture were calculated using the available data in the international libraries in accordance with  SRIM code . Theoretical calculations of the thick target integral yields were deduced using the calculated cross sections by using Matlab program

Results: When proton induced reaction on ⁷⁵As, ⁷⁴Se, ^natSe and ^natBr  to obtain ⁷³Se, the reaction ⁷⁵As(p,3n)  with range of energy (22.5 to 45.5 MeV) and the maximum cross section is 315 mb at 36.5 MeV gives maximum yield (2*10⁶  GBq/C).while  for the reaction ⁷⁵As (d,4n) ⁷³Se with range of energy (25 to 56 MeV) , and maximum cross sections is 30 mb at 43MeV gives (0.085*10⁶  GBq/C).

The three reactions ^natGe (³He,x) , ⁷⁰Ge (α,n)  and ⁷²Ge (α,3n) show that the best reaction to obtain ⁷³Se is ⁷²Ge (α,3n) within the range of energy (27 to 46 MeV) and maximum cross sections 494 mb at 42MeV  give the maximum yield (0.03*10⁶  GBq/C).

Conclusion: the use of proton as projectile is best compared with other particles in order to get maximum isotopes production yield of 73Se.