Uses of alpha particles, especially in nuclear reaction studies and medical radionuclide production

Abstract

Alpha particles exhibit three important characteristics: scattering, ionisation and activation. This article briefly discusses those properties and outlines their major applications. Among others, -particles are used in elemental analysis, investigation and improvement of materials properties, nuclear reaction studies and medical radionuclide production. The latter two topics, dealing with activation of target materials, are treated in some detail in this paper. Measurements of excitation functions of -particle induced reactions shed some light on their reaction mechanisms, and studies of isomeric cross sections reveal the probability of population of highspin nuclear levels. Regarding medical radionuclides, an overview is presented of the isotopes commonly produced using -particle beams. Consideration is also given to some routes which could be potentially useful for production of a few other radionuclides. The significance of -particle induced reactions to produce a few high-spin isomeric states, decaying by emission of low-energy conversion or Auger electrons, which are of interest in localised internal radiotherapy, is outlined. The -particle beam, thus broadens the scope of nuclear chemistry research related to development of non-standard positron emitters and therapeutic radionuclides.

Nuclear data for medical applications: An overview of present status and future needs

“…All the three radionuclides constitute a high-spin isomeric state of the respective isotope. As discussed recently in detail [31], such states are preferentially populated in α-particle induced reactions. Some production data for the three radionuclides are available [cf.…”

Development of novel radionuclides for medical applications

“…A detailed discussion on the use of different charged‐particle–induced reactions over several energy ranges for the production of novel positron emitters is given in several references . We consider below 4 radionuclides, namely, 64 Cu, 86 Y, 124 I, and 73 Se.…”

“…The calculated thick target yields, however, showed that owing to the very short range of α particles, the (α,n) reaction is not very advantageous (cf Figure 2). From those yields and also considering the levels of the associated longer‐lived impurities 75 Se ( T ½ = 120.0 d) and 72 Se ( T ½ = 8.5 d), it was concluded that the 75 As(p,3n) 73 Se reaction over the energy range of E p = 40 → 30 MeV is most suited. The yield of 73 Se amounts to 1400 MBq/μA·h, and the levels of 75 Se and 72 Se impurities are 0.05% and 0.11%, respectively, of the amount of 73 Se.…”

Labelling with positron emitters of pnicogens and chalcogens

“…Furthermore, the nuclear process nat Br(p,x) 73 Se was investigated, providing 73 Se with only minimal impurities . A critical analysis of the various competing reactions for the production of 73 Se was recently presented …”