Proton and ³He Induced Nuclear Reactions in Uranium and Neptunium Targets. Production of Neptunium and Plutonium Tracers with a Low-energy Cyclotron

Production of235Np,236Pu and237Puvianuclear reactions on235,236,238U and237Np targets

“…The alpha-emitter 236 Pu (T 1/2 = 2.858 ± 0.008 y [2]) is mainly used as a tracer for the control of 238,239,240 Pu release into the environment from the nuclear fuel cycle. The following 236 Pu production reactions have been studied [3][4][5][6][7][8][9][10][11][12][13][14][15][16]:…”

“…*Author for correspondence (E-mail: sven-johan.heselius@abo.fi). 5 Present address: KVI Zernikelaan 25, 9747 AA Groningen, The Netherlands.…”

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

“…In a review work [3] it was concluded that the most efficient reactions to produce 235 Np are 236 U( p, 2n) 235 Np at proton energies lower than 18 MeV [4,5] and 238 U( p, 4n) 235 Np at energies from 18 to 50 MeV [6,7]. In reactions in the actinide region the competition between fission and neutron evaporation of the compound nucleus is decisive in the formation of the end product.…”

“…In work [3] it was stated that the highest radionuclidic purity of 236 Pu can be obtained by the 236 U( p, nβ − ) 236 Pu reaction, where the impurity of 238 Pu produced in the 238 U( p, nβ − ) reaction depends only on the abundance of 238 U in the enriched 236 U target. The cross sections and yields of the 236 U( p, nβ − ) 236 Pu reaction have been determined in works [4,5] for proton energies lower than 18 MeV.…”

“…Thick-target yields of 236 Pu (1), 235 Np (2) and 234 Np(3 and 4) in the proton-induced reactions on 236 U, calculated on the basis of the cross sections measured in this work and[3][4][5]. Curve No.…”