Transmutation studies using SSNTD and radiochemistry and the associated production of secondary neutrons

Transmutation of239Pu and other nuclides using spallation neutrons produced by relativistic protons reacting with massive U- and Pb-targets

“…Uncertainties of about ±12% are due to statistical uncertainties in the measurements and systematic uncertainties in the monitor reaction cross-sections. Fluences based on 24 Na determinations in Al-foils of monitor 2 at a distance of 35 cm upstream of the massive target give consistent results for the proton fluence with the other 3 monitor reactions: 7 Be and 22 Na in Al and 24 Na in Cu. These latter three reactions are insensitive to lowenergy secondaries [10].…”

“…The distribution of neutrons, measured via 140 La or 239 Np on top of the surface of the moderator is also known from previous experiments [5][6][7][8]: The maximum induced radioactivity is always found about 5 cm behind the entrance of the protons into the massive uranium target, rather independent of the energy of the incoming proton. For a lead target this maximum is about 10 cm behind the entrance of the protons into the massive lead block.…”

“…3a,b for irradiations at 0.53 GeV and 1 GeV proton energy. The beam profile at 1.0 GeV proton is characteristic of experiments at this energy and higher energies [5][6][7][8]. The entire beam essentially matches the 8 cm ∅ metallic target and the beam is attenuated within the 20 cm long target, though it is not completely stopped.…”

“…[5,8]. Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 5/28/15 3:26 PM sults have been presented before: B-values from the Pbtarget are reduced by a factor 1/1.7 as compared to U/Pb-targets [5][6][7][8].…”

“…They studied the transmutation capacity of thermal neutrons, produced by 1 GeV protons interacting with a lead target within an extended subcritical nuclear power plant. Our team has backed their theoretical approach with experiments and published a series of papers on the transmutation of 129 I, 237 Np, nat U, and stable 139 La in recent years [4][5][6][7][8]. We used a small metallic target system surrounded by 6 cm paraffin as partial moderator irradiated with low-intensity relativistic proton beams of the Synchrophasotron at the Laboratory of High Energies, Joint Institute for Nuclear Research (JINR), Dubna, in Russia.…”