Premium
Production of radioisotopes by direct electron activation
Author(s) -
Weeks K. J.,
O'Shea P. G.
Publication year - 1998
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.598224
Subject(s) - electron , atomic physics , tantalum , neutron , nuclear physics , photon , kinetic energy , physics , cross section (physics) , materials science , optics , quantum mechanics , metallurgy
High‐energy electrons bombarded on materials can induce radioactivity by either directly knocking out neutrons or by first converting a fraction of the electron kinetic energy into electromagnetic energy, with subsequent neutron emission induced by the photons produced. The purpose of this paper was to develop a calculation method for estimating neutron emission and radionuclide production by high‐energy (15–25 MeV) electrons directly interacting with a nucleus. The reaction ( e , n ) is considered using the method of virtual photons. The cross section for electron bombardment of lead, tantalum, rhenium, and tungsten targets is calculated. The electron cross sections are roughly 100 times less than the corresponding photon cross sections. The cross section increases monotonically with incident energy. A traveling wave linear accelerator was used for a qualitative test of the magnitude and energy dependence of the calculated cross sections. Tantalum was bombarded with electrons and the resultant emission of neutrons was inferred from the induced activation of180 Ta . The energy dependence and magnitude of the calculated electron cross sections agree with experiment within experimental uncertainties. It is concluded that accurate estimates of electron activation via the direct process is possible.