Highlights from a recent test campaign in Finland with scalable neutron detectors

Transcription

1 Highlights from a recent test campaign in Finland with scalable neutron detectors Neutron Users Club Dr. Geraint Dermody

2 Introduction Symetrica s activities and products The NKS (Nordic Nuclear Safety Research) initiative and the NOVE test campaign in Finland Results for two Symetrica detector types NNS:2000 an established 6 LiZnS radiation portal monitor module. NNS:FP new 6 LiZnS modules with solid state readout. Future work and conclusions

3 Symetrica s Activities Instruments for the Detection and Identification of radioactive material for security applications 100% Cargo Screening US Department of Homeland Security Aim Felixstowe Fears of Dirty Bomb Attack Reported November 2011 Sunday Mirror Resilience & recovery Fukushima Daiichi power plant Symetrica is a small, innovative UK company focussing on the Homeland Security Market with ambitions worldwide.

4 One Technology, Multiple Products RadSeeker Mobile Personnel Cargo / Vehicle BackPack Belt Worn Neutron Sensors

5 The NOVE Test Campaign NKS (Nordic Nuclear Safety Research) is an informal forum for Nordic cooperation and competence in nuclear safety, including emergency preparedness. NOVE: Novel neutron detection methods for nuclear security NOVE has comprised of a neutron detector workshop in Iceland and inter-comparison measurements at STUK. The project finishes off with a report from these studies. The Symetrica test results presented here are courtesy of the NOVE test campaign carried out at the Radiation Metrology Laboratory of STUK, the Finnish Radiation and Nuclear Safety Authority.

6 Detectors Tested Standard 6 LiZnS detector Module NNS:2000 2m 252 Cf Miniature 6 LiZnS Detection System NNS:FP Solid State Readout 2m NNS:FP

7 NNS:2000 Overview

8 NNS: Efficiency NNS:2000 efficiency comparisons for bare sources at 2m 2.E-03 2.E-03 1.E-03 Efficiency (counts / neutron) 1.E-03 1.E-03 8.E-04 6.E-04 4.E-04 2.E cps/ng 0.E MBq 252Cf; Bare Source 11GBq AmBe; 3mm Pb

9 NNS:2000 Effect of Shielding Effect of shielding for 252Cf and AmBe Efficiency relative to bare source mm Pb 100mm Pb 140mm HDPE 500mm borated PE Shielding 252Cf AmBe

10 NNS:2000 Gamma Rejection Measured Gamma Rejection Ratio NNS:2000 Gamma Rejection Ratio (GRR) 5.E-07 4.E-07 3.E-07 GRR 2.E-07 1.E-07 0.E uSv/hr 137Cs Exposure 175uSv/hr 60Co

11 NNS:2000 Adaptive Threshold Example health system plots Includes gamma and HV monitoring

12 NNS:2000 Extensive Testing Modules tested initrap+10 and Port Deployments

13 NNS:FP Realising Scalability NNS:FP 500g each 2 detectors tested Solid state readout Scalable modules

14 NNS:FP Test setup (GRR) STUK Test Facility

15 NNS:2000 Efficiency NNS:FP efficiency comparisons for bare sources at 2m 1.8E E E-04 Efficiency (counts / neutron) 1.2E E E E E E cps/ng 0.0E+00 14MBq 252Cf; Bare Source

16 NNS:2000 Effect of shielding Effect of shielding for 252Cf and AmBe *All values are relative to 30mm Pb Efficiency relative to source shielded with 30mm Pb mm Pb 100mm Pb 140mm HDPE Shielding 252Cf AmBe

17 NNS:2000 Gamma Rejection NNS:FP False Neutron Rate 5 4 False Neutron Rate (cps) uSv/hr 137Cs 175uSv/hr 60Co 540uSv/hr 60Co Typically <1 n/s at 540µSvh Exposure

18 Relative Sensitivity NNS:2000 and NNS:FP relative sensitivity Efficiency (cps/ng) kg NNS:2000 Detector kg NNS:FP Modules tested initrap+10 and Port Deployments

19 Future Work SiPM readout allows for further scaling and portable instrument optimisation Application specific detectors solutions for pagers, handhelds, search detectors, backpacks and dosimeters. Further benchmarking campaign planned at JRC.

20 Conclusions We have developed a 3 He free technology for RPMs (NNS:2000 & NNS:4000) We have flat panel neutron detectors and miniature tube geometry sensors that use solid-state readout A range of 6 Li6ZnS Neutron detectors is available and others are under development!