Research ArticleOpen AccessGoogle Scholar indexed
Pass/Fail Criterion for a Simple Radiation
Statistical Sciences, Los Alamos National Laboratory, Los Alamos, USA
Neutron Science Center, Los Alamos National Laboratory, Los Alamos, USA
- 1 Statistical Sciences, Los Alamos National Laboratory, Los Alamos, USA
- 2 Neutron Science Center, Los Alamos National Laboratory, Los Alamos, USA
Copy link · social · email
Abstract
One of the simplest tests of a radiation portal monitor (RPM) is a series of n repeats (a vehicle drive-through) in which the ith repeat records a total number of counts Xi and alarms if Xi ≥ T where T is an alarm threshold. The RPM performance tests we consider use n repeats to estimate the probability p = P(Xi ≥ T). This paper addresses criterion A for testing RPMs, where criterion A is: for specified source strength, we must be at least 95% confident that p ≥ 0.5. To assess criterion A, we consider a distribution-free test and a test relying on assuming the counts Xi have approximately a Poisson distribution. Both test options require tolerance interval construction.
KeywordsPoisson DistributionRadiation Portal MonitorTolerance Interval
- B. Geelhood, J. Ely, R. Hansen, R. Kouzes, J. Schweppe and R. Warner, “Overview of Portal Monitoring at Border Crossings,” 2003 IEEE Nuclear Science Symposium Conference Record, Portland, 19-25 October 2003, pp. 513-517. doi:10.1109/NSSMIC.2003.1352095
- J. Ely, R. Kouzes, J. Schweppe, E. Siciliano, D. Strachan and D. Weier, “The Use Of Energy Windowing to Discriminate SNM from NORM in Radiation Portal Monitors,” Nuclear Instruments and Methods in Physics Research A, Vol. 560, No. 2, 2005, pp. 373-387. doi:10.1016/j.nima.2006.01.053
- T. Burr, J. Gattiker, M. Mullen and G. Tompkins, “Statistical Evaluation of the Impact of Background Suppression on the Sensitivity of Passive Radiation Detectors,” Springer, New York, 2006.
- T. Burr, J. Gattiker, K. Myers and G. Tompkins, “Alarm Criteria in Radiation Portal Monitoring,” Applied Radiation and Isotopes, Vol. 65, No. 5, 2007, pp. 569-580. doi:10.1016/j.apradiso.2006.11.010
- T. Burr and M. Hamada, “The Performance of Neutron Alarm Rules in Radiation Portal Monitoring,” in Revision for Technometrics, 2012.
- R. Kouzes, E. Siciliano, J. Ely, P. Keller and R. McConn, “Passive Neutron Detection For Interdiction Of Nuclear Material At Borders,” Nuclear Instruments and Methods in Physics Research A, 584, No. 2-3, 2008, 383-400. doi:10.1016/j.nima.2007.10.026
- D. Young, “Tolerance: An R Package for Estimating Tolerance Intervals,” Journal of Statistical Software, Vol. 36, No. 5, 2010. www.jstatsoft.org
- R Development Core Team. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, 2004. http://www.R-project.org
- S. Robinson, S. Bender, E. Flumerfelt, C. LoPresti, M. Woodring, “Time Series Evaluation of Radiation Portal Monitor Data for Point Source Detection,” IEEE Transactions on Nuclear Science, Vol. 56, No. 6, 2009, pp. 3688-3693. doi:10.1109/TNS.2009.2034372
- T. Schroettner, P. Kindl and G. Presle, “Enhancing Sensitivity of Portal Monitoring at Varying Transit Speed,” Applied Radiation and Isotopes, Vol. 67, No. 10, 2009, pp. 1878-1886. doi:10.1016/j.apradiso.2009.04.015