Experimental determination of 80,82,83Kr(α, xn)82Sr cross sections for reaction threshold to 60 MeV α-particles

Abstract

The activation method has been used to determine the experimental cross sections of the nuclear reactions 80 Kr(α, 2n) 82 Sr, 82 Kr(α, 4n) 82 Sr, and 83 Kr(α, 5n) 82 Sr for α-particle energies from the reaction threshold to E α = 60 MeV on targets which are highly enriched with krypton isotopes. The structural and geometric parameters are established for a "thick" cascade target with krypton isotopes, which gives maximum 82 Sr yield for E α ≤ 60 MeV. The 82 Sr yield in the indicated target for initial energy E α = 60 MeV is estimated to be 3.4·10 6 Bq/(µA·h), which gives a basis for commercial applications of this isotope in medium-energy accelerators.One of the most promising and dynamically developing directions in nuclear medicine today is cardio-diagnostics based on positron emission tomography. Most positron emission tomography centers use ultra-short-lived β + remitting radionuclides ( 11 C, 13 N, 15 O, 18 F) and operate with two mandatory components: positron emission tomography and a cyclotron with E p < 20 MeV for producing the indicated isotopes. Undoubtedly, the need for a cyclotron is preventing wider use of PET, since not every clinic has a cyclotron. There is a more efficient approach to the solution of this problem.A method of positron emission tomography, based on the use of the isotope generators 82 Sr-82 Rb, has been developed, mainly, in the USA. These generators are compact, can be easily delivered to a clinic, including over large distances, and have a long service life. In addition, there is no need to have and operate a cyclotron in a clinic.At the present time, 82 Sr is obtained in the reactions Mo(p, spallation) and Rb(p, xn) in unique expensive high-energy (E p~ 100-800 MeV) accelerators which are intended for fundamental research [1][2][3][4]. Aside from the indicated reactions, 82 Sr can be obtained by irradiating gaseous krypton targets with 3 He or 4 He in cyclotrons, which are relatively inexpensive to operate, with average energy (E α, 3 He ≤ 60-70 MeV) [5,6]. The highest yield of 82 Sr in this method can be attained with a cascade target, consisting of modules highly enriched with krypton isotopes. In such a target, 82 Sr will be produced simultaneously on several krypton isotopes: on each krypton isotope in the α-particle energy range where the 82 Sr production cross section is larger than for other isotopes [7]. To realize such a cascade target, it is necessary to know the energy dependences of the cross sections of reactions in which 82 Sr is formed on all krypton isotopes. At the present time, there are no experimental data on the cross sections of the nuclear reactions 80,82,83 Kr(α, xn) 82 Sr. This makes it important to obtain the experimental cross sections of the nuclear reactions leading to the formation of 82 Sr on krypton isotopes.In the present work, the activation method was used to determine the experimental cross sections of the nuclear reactions 80 Kr(α, 2n) 82 Sr, 82 Kr(α, 4n) 82 Sr, and 83 Kr(α, 5n) 82 Sr at energies from the reaction threshold to ...

Production cross-section and reaction yield of 82Sr for 82Sr/82Rb generator

“…Determiden the best values obtained as 193, 173 and 110 mb at 33, 45 and 64 MeV, respectively [12]. Apart from these, many different studies are avaible in the literature for the production of 82 Sr radioisotope; nat Rb(d,xn) 82 Sr [13], and nat,80,82,83 Kr(α,xn) 82 Sr [14]. In this study, we have investigated some possible production mechanisms of 82 Sr by regarding 82 Sr/ 82 Rb generator.…”