New Trends in Neutron Coincidence Counting: Digital Signal Processing

Neutron coincidence counting is the reference NDA technique used in nuclear safeguards to measure the fissile mass in nuclear material samples. Nowadays most of the neutron counting systems are based on the original shift register technology, like the (ordinary or Multiplicity) Shift Register Analyser. The analogue signal from the He-3 tubes is processed by amplifier/SCA producing a train of logical TTL pulses that are fed into a neutron analyser performing the time correlation analysis. In the future these systems could be replaced by high-speed PC’s equipped with pulse acquisition cards, providing a time stamp (LIST mode acquisition) for every digital pulse. The time stamp data can be processed directly during acquisition or saved on a hard disk. The latter method has the advantage that measurement parameters, like for instance the pre-delay and gate-width, can be modified without repeating the acquisition. The use of PC based instruments, also called virtual instruments, could be the future major development in practical neutron correlation analysis. Under a push from the main inspection authorities (IAEA, Euratom and French Ministry of Industry) several research laboratories have started to study and develop prototypes of neutron counting systems with PC-based processing. A collaboration in this field among JRC, IRSN and LANL has been established within the framework of the ESARDA-NDA working group. Joint testing campaigns have been performed in the JRC PERLA laboratory, using different equipment provided by the three partners. The paper will describe the rationale for changing to the new technology, give an overview of the hardware and software tools available today and a feedback of the experience gained in the first tests. Associated to the experimental tests, the ESARDA-NDA working group is also performing an inter-comparison benchmark exercise on the analysis software for pulse processing.

PEERANI Paolo;  MARIN FERRER Montserrat;  LOOMAN Marc;  SWINHOE Martyn;  WEBER Anne-Laure; 

2007-10-16

OPOCE

JRC37489

http://npns-int.jrc.it/zp_les_cd/2007-05-22-29th-Annual_Meeting-ESARDA/index.htm?PHPSESSID=6ef834bdb81c1212959dda6c8bda057c,    https://publications.jrc.ec.europa.eu/repository/handle/JRC37489,