title: Neutron interrogation of shielded/unshielded uranium by a 4 MeV linac.
abstract: A non-destructive active assay method was developed for revealing illicit trafficking of uranium. Photoneutrons produced in beryllium or heavy water by bremsstrahlung from a linac induced fission in the samples. Delayed fission neutrons were detected by a neutron collar built up of (3)He counters embedded in polyethylene moderator. High-enriched uranium samples shielded and unshielded by lead up to 14 mm thickness were detected, with a performance practically unaltered. 25 mg (235)U can be revealed in a 1 min interrogation time.
authors.affiliation: Institute of Isotopes, Hungarian Academy of Sciences, Budapest, Hungary. lakosi@iki.kfki.hu
authors.forename: L
authors.initials: L
authors.lastname: Lakosi
authors.forename: C Tam
authors.initials: CT
authors.lastname: Nguyen
authors.forename: E
authors.initials: E
authors.lastname: Serf