First experiments on transmutation studies of 129 I and 237 Np using relativistic protons of 3.7 GeV

First experiments on the transmutation of long-lived 129 I and 237 Np using relativistic protons of 3.7 GeV are described. Relativistic protons generate in extended Pb-targets substancial neutron fluences. These neutrons get moderated in paraffin and are used for transmutation as follows: 129 I(n,γ) 130 I β → and 237 Np(n,γ) 238 Np β →. The isotopes 130 I ( T 1/2 -12.36 h) and 238 Np ( T 1/2 =2.117 d) were identified radiochemically. One can estimate the transmutation cross-section (n,γ) in the given neutron field as σ( 129 I(n,γ))=(10±2)b and σ( 237 Np(n,γ))=(140±30)b The experiments were carried out in November 1996 at the Synchrophasotron, LHE, Dubna, Russia. The investigation has been performed at the Laboratory of High Energies, JINR, Dubna.