HELNED Helium3 free lowcost neutron detectors Paolo Finocchiaro

HELNED: Helium-3 -free low-cost neutron detectors Paolo Finocchiaro Luigi Cosentino, Carmelo Marchetta, Alfio Pappalardo, Sergio Scirè, Carlotta Scirè, Gianfranco Vecchio INFN Laboratori Nazionali del Sud, Catania, Italy n 3 H 6 Li 7 Li 4 He Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 1

where did we start from? radioactive waste in almost every country in the world Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 2

we implemented a low-cost granular radwaste monitoring system (gamma rays) see tomorrow’s talk of Alfio Pappalardo DMNR Detector Mesh for Nuclear Repositories local data storage Web wireless network Data wired network Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 remote data storage 3 He-free low-cost neutron detectors P. Finocchiaro 3

upgrade: thermal neutron monitoring out-of-core monitoring in NPP why neutrons? spent fuel monitoring in place and/or during transportation Plutonium, I love you. . . detection of possible diversion of fuel elements from Castor containers (P. Peerani, M. Galletta, Nuclear Engineering and Design 237 (2007) 94 -99) Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 4

ensuring continuity of knowledge current monitoring method: video camera our idea: granular, real time, automatic Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 5

How? materials for thermal neutron conversion: 3 He 3 H n 3 He p (0. 025) ≈ 5330 b available energy 0. 76 Me. V no gamma rays perfect gas detector but. . . worldwide lack of 3 He Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 6

materials for thermal neutron conversion: which one? 6 Li 10 B (0. 025) ≈ 940 b available E 4. 78 Me. V 157 Gd (0. 025) ≈ 240 kb 113 Cd (0. 025) ≈ 20 kb (0. 025) ≈ 3840 b available E 2. 79 Me. V (and gamma rays) Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 large available E but in form of gamma rays: difficult neutron identification 3 He-free low-cost neutron detectors P. Finocchiaro 7

physical process 6 Li – natural abundance: 7% thermal neutrons a 6 Li. F converter captures a neutron. . . n Cross section ≈ 940 b 6 Li 7 Li detection of 3 H and/or 4 He 2. 05 Me. V 3 H 2. 73 Me. V how? . . . and produces 4 He ed 3 H which can be detected Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 8

3 He-free Lithium-based NEutron Detectors with removable converter Am. Be neutron source 5 E 4 n/s thermal flux ≈ 4 n/s/cm 2 9 cm 2 Si detector + 6 Li. F(1. 5µm) 3 cm x 3 cm Si 6 Li. F difference between spectra not needed to reject gammas n/gamma ≈ 10 -5 neutrons gamma background Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 9

Si detector + 6 Li. F: comparison with simulation semi-quantitative GEANT 4 simulation: • neutrons: thermal • gamma: 60 ke. V • gamma: 662 ke. V • gamma: 1. 2 Me. V • gamma: 4 Me. V • # alpha and tritium normalized to data • # gamma manually scaled quite encouraging data-simulation agreement (surprising? ) Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 10

Am. Be neutron source 1. 6 E 6 n/s thermal flux ≈ 150 n/s/cm 2 Si + 6 Li. F neutron source ≈ neutrons gamma background Alpha 100% neutrons PET castle Tritium expected ≈ 4 cps Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors measured 3. 3 P. Finocchiaro 11

Si detector + 6 Li. F thickness: 1. 8µm vs 1. 5µm 20% more efficient ΔE calculated: 195 ke. V ΔE measured: 200 ke. V optimal 6 Li. F thickness 1. 8µm added 2 gamma sources to test rejection (740 MBq) Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 12

Si detector + 6 Li. F on glass double sided silicon 3 cm x 300µm 6 Li. F on plastics 2 converters: double efficiency Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 13

Si detector + 6 Li. F lin log no source: background 2 converters: double efficiency (2%) no converter: only gamma contribution but. . . in log scale. . . unexpected neutrons? part of the 6 Li. F migrated from the plastic substrate to the silicon face! Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 14

Si detector + 6 Li. F lin heavy material close to the detector: higher energy gamma (scattering) heavy material removed: the gamma background is suppressed same as before in log scale log advice: no heavy material inside the PET moderator Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 15

Si detector + 6 Li. F collaboration with n. TOF @ CERN Si Si 3 H 6 Li foil 4 He Si Si Si. Mon 2: neutron beam monitor flux normalization Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 16

Si detector + 6 Li. F collaboration with n. TOF @ CERN 6 Li foil 16 -strip Si forward-backward asymmetry XY distribution Bea. Mon: neutron beam characterization Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 17

features • mechanically simple and robust • reasonably cheap • commercial solid state detectors • strips for position measurements • simple use (no spectrum analysis or subtraction for gamma rejection) next steps better efficiency (up to 50%? ) 6 Li deposits over large area (A 4) scintillators. . . Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 patent? YES 3 He-free low-cost neutron detectors P. Finocchiaro 18

. . . with scintillator detectors ne ut ro ns Po sit io n alpha + gamma Lig tritium neutrons ht alpha + gamma tritium neutrons • good intrinsic efficiency • position sensitive (Δx ≈ 1 -2 mm) • low cost • many possible geometries and schemes RM 2013 A 000254 filed on 2013 -04 -29 Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 19

real-time castorage monitoring local data storage remote data storage Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 Web 3 He-free low-cost neutron detectors P. Finocchiaro 20

real-time castorage monitoring collaboration with JRC & Euratom. . . wireless transmission easily integrated into the existing hardware and software architecture of DMNR: electronics data acquisition system control data logging database handling Graphical User Interface Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 21

possible applications • Nuclear physics research • Homeland security (nuclear material smuggling) • Dosimetry • Radwaste monitoring • Spent fuel handling and storage monitoring • Search for nuclear material accidentally lost among scrap metal • Material structure (with neutron beams) • other. . . Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 22

applications with neutron beams Neutron Resonance Capture Analysis e. g. : Ancient Charm EU project Time-of-Flight Neutron Diffraction (To. F- ND) e. g. : University of Milan, inorganic stereochemistry secrets of Bronze Age sword unveiled Bragg Edge Transmission e. g. : S. Petriw, J. Dawidowski, J. Santisteban, Porosity effects on the neutron total cross section of graphite Journal of Nuclear Materials 396 (2010)181 -188 Neutron Radiography e. g. : Institute of Atomic and Subatomic Physics - TU Wien neutron X-ray material analysis: composition and structure Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 23

compact neutron monitors? Third European Energy Conference E 2 C 2013 Budapest 27 -30 October 2013 3 He-free low-cost neutron detectors P. Finocchiaro 24

thank you picture: ETNA volcano eruption, Catania 2013