Proton-induced nuclear reactions in neptunium-237 targets. Production of plutonium tracers in the energy range 15-40 MeV

Production of energetic 232U, 236,238Pu, 242Cm, 248Bk, 250,252Cf and 252Es radioisotopes for use as nuclear battery in thin targets via particle accelerators

Energetic ²³²U, ^236,238Pu, ²⁴²Cm, ²⁴⁸Bk, ^250,252Cf and ²⁵²Es nuclei used in nuclear batteries were produced by using particle accelerators for proton, deuteron, triton, helium-3 and alpha-induced reaction processes on thin targets. The energy range used was E_particle = 100 → 1 MeV, including specific conditions such as irradiation time of 24 h with constant beam current of 1 μA. The impressive results were obtained in terms of charged-induced reaction processes, based on simulated activity and yield of product curves. In addition, the significance of these results was discussed for each reaction process so as to determine the appropriate reaction process in detail and add nuclear data to the literature. Also, obtaining these radioisotopes has loud economic cost and restrictions of target materials. Therefore, target materials in production processes were carried out in thin targets to provide convenience to experimenters.

Production of 234,235Np and 236Pu in bombardment of 236U with protons in the energy range from 17 to 40 MeV

The production of 235Np and 236Pu by the reactions 236U(p,2n) 235Np and 236U(p,nβ−) 236Pu using the K-130 cyclotron of the University of Jyväskylä was investigated. The cross sections for the reactions were determined. Thick-target yield curves were derived based on the cross sections. The results are discussed and compared with previous data on other reactions leading to the formation of the same end products. The thick-target yield of 235Np in the 236U(p,2n) reaction is about 50 percent higher than the yield obtained in the 238U(p,4n) reaction leading to this nuclide at comparable particle energies. The purity of 236Pu produced in the 236U(p,nβ−) reaction is more than ten times better than for earlier known as the purest reaction 237Np(p,2n+pnβ−) 236Pu.

Production of 235Np, 236Pu and 237Pu via nuclear reactions on 235,236,238U and 237Np targets

A summary of methods for cyclotron production of 235Np (396.1d), 236Pu (2.858y) and 237Pu (45.2d) via nuclear reactions with protons and 3He-ions on 235,236,238U and 237Np targets in wide energy ranges is given. Methods for the chemical separation and purification of these nuclides from the irradiated uranium and neptunium targets are described. Cross sections, yields and radionuclidic purities of 235Np, 236Pu and 237Pu are presented and compared with literature data on the nuclear reactions leading to these radionuclides. The nuclear reactions with the so far highest known yields of 235Np, 236Pu and 237Pu are determined: 236U(p,2n) 235Np, 237Np(p,2n+pnβ -) 236Pu and 237Np(p,n) 237Pu, respectively. The highest radionuclidic purity of 235Np, 236Pu and 237Pu tracers can be reached with the 236U(p,2n) 235Np, 236U(p,nβ -) 236Pu and 237Np(3He,t) 237Pu reactions, respectively. In addition new cross sections and yield data of the 236U(3He,p3n) 235Np reaction in the energy range 42.4–60 MeV are given.