Preliminary Progress of Developing the Plutonium Mass Attribute Assay Equipment

On the demand of material control and assay(MC&A) of plutonium metal components used or deposited in lab for critical assembly research, a plutonium mass attribute assay equipment, which comprises of neutron multiplicity counter, nuclear electronic module, neutron signal acquisition and codes for multiplicity analysis and data algorithm, has been developing. The counter has a cavity with 45cm in width and depth, 56cm in height which can hold the standard container of plutonium sample, and the software can do the Rossi-a, multiplicity analysis, calibration, plutonium mass assay. A suit of preliminary experiments was carried out with several Cf-252 neutron sources in different strength to calibrate the equipment’s parameters, and with some components of plutonium metal to test its comprehensive performance for plutonium assay. The preliminary results show that the primary specifications of the equipment for the MC&A are achieved; meanwhile more work or improvements need to be done for promoting its practical application.