Production of²³⁵Np,²³⁶Pu and²³⁷Puvianuclear reactions on^235,236,238U and²³⁷Np targets

A summary of methods for cyclotron production of Np-235 (396.1 d), Pu-236 (2.858 y) and Pu-237 (45.2 d) via nuclear reactions with protons and He-3-ions on U-235.236,U-238 and Np-237 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 Np-235, Pu-236 and Pu-237 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 Np-235, Pu-236 and Pu-237 are determined : U-236(p, 2n)Np-235, Np-237(p, 2n + pnbeta(-))Pu-236 and Np-237(p, n)Pu-237, respectively. The highest radionuclidic purity of Np-235, Pu-236 and Pu-237 tracers can be reached with the U-236(p, 2n)Np-235, U-236(p, nbeta(-))Pu-236 and Np-237(He-3, t)Pu-237 reactions, respectively. In addition new cross sections and yield data of the U-236(He-3, p3n)Np-235 reaction in the energy range 42.4-60 MeV are given.