Combined Fast Neutron and Dual Energy GammaRay Transmission (NEUDEG) Measurements to Non- invasively Assess Materials Murray Bartle Imaging Laboratory, GNS Science, Gracefield Rd., Lower Hutt, New Zealand IAEA Co-ordinated Research Programmes IAEA RCA Asia Pacific Programme IAEA Expert Missions in S E Asia.
Outline• Dual beam systems in industry• Neutron gamma transmission• Dual energy x-ray absorption• IAEA activities Asia – Pacific• Fast neutrons and dual energy gamma rays
Measurement of Meat Fat Content hydrogen carbon nitrogen oxygen n(H) per EAN wt% wt% wt% wt% gmLEAN 10 10 3 77 6.15 x 1022 7.64*(approx)FAT 15 74 0 11 9.05 x 1022 5.83 * includes minerals
A. Simultaneous fast neutron and gamma ray transmission from a 252Cf source NEUGAT LAYOUT Tank water Source (0.2 μg 252Cf)conveyor ^ 0.4m 0.25m Test material n PSD n+g liquid organic scintillator Neutron and gamma ray events in the scintillator can be separated by PSD
Fig. 6. The NEUGAT system called ‘Phoebe’ based on a 252Cf source and a 6 litreorganic liquid scintillation detector. The source is mounted in the top tank filled withwater and the detector is mounted under the conveyor. Neutron and gamma ray events areseparated by pulse shape discrimination.
60 LOW AND HIGH DENSITY WOOD CHIPSNEUGAT WATER CONTENT (WT%) 50 40 O High density low density 30 chips Low density high density chips 20 10 10 20 30 40 50 60 CALIBRATION WATER (WT%)
difference: neutrons - gamma absorption (counts) v sum of absorptions polyethylene layers difference in absorption 1.0 0.8 acrylic layers NEUGAT (counts) 0.6 0.4 water layers 0.2 0.0 sand layers 0.0 0.2 0.4 0.6 0.8 1.0 sum absorption (counts)Features of NEUGAT in the context of industrial applications:1. Including neutrons as one of the beams provides sensitivities to the presence of light elements in materials.2. Use of neutrons as one of the beams limits the possibility of using imaging.3. The shielding of neutrons in an industrial environment is more difficult that x-rays or gamma rays.4. Organic detectors with large volumes have moderate cost but need to use liquid organic scintillators for PSD limits the possibilities in industry due to fire risk.5. PSD electronics are unreliable in an industrial context.
Dual energy photon beams COALSCAN 2100 - Scantech Australia ‘The COALSCAN 2100 is a new configuration in the Dual Energy Transmission (DUET) ash gauges and offers all the accumulated operational experience gained since COALSCANs were first developed, but at a significantly reduced price.’ Need to be able to resolve the two gamma ray energy groups in the detector and also count at high count-rates. Inorganic scintillators give good energy resolution, but are either expensive (e.g. LaCl3) or slow (e.g. NaI(Tl)) adding cost or providing limited count-rates Sizes of detector are limited by cost.
B. MEAT SCANNING. Dual energy x-rays resolved in separate detector (arrays) Highly engineered production scale and speed scanning system XADA detector Fig1. The effective LE (red line) and 50 x-ray spectrum absorption: low detector absorption: high detector HE (blue line) x-ray energy bands produced in the Eagle DEXA scanner, derived bynumber of photons [a.u.] 40 filtering the total x-ray spectrum (black line) 30 from the x-ray source at the detector. The two 20 peaks are characteristic x-ray lines; the lower energy peak is Kα and the higher 10 energy peak is Kβ. The underlying continuous 0 distribution is from bremsstrahlung radiation. 20 40 60 80 100 120 140 energy [keV] Fig.2. The Eagle DEXA scanner used in these measurements is located in the Isotope and X-ray Imaging Laboratory, National Isotope Centre, GNS Science, Lower Hutt, New Zealand. (Note: DEXA scanners are also deployed at airports (luggage scanning) and hospitals (in vivo bone density measurement).
AA=LOW energy detector CC BB=filter CC=HIGH energy detectorAA BB Basic components of a dual energy detector element
30000 Aluminium (Al) Z=13 25000 glass-based scintillatorsDifference in absorptions LE - HE (arbitrary units) 20000 polycarbonate polystyrene-based scintillators 15000 mu metal A 75%Ni 25%Fe 10000 iron strip (Fe) Z=26 5000 mu metal B 75%Ni 25%Fe 0 silver (Ag) Z=47 0 0.2 0.4 0.6 0.8 1 soda lime glass Summed absorptions LE + HE (normalised)
DEXA Absorption Curves 1.6 Fig.3 DEXA absorption curves for with a range of atomic numbers (elements) or effectiveLE - HE beam absorption Acrylic + aluminium 1.4 layers 1.2 atomic numbers (compounds/alloys). A Acrylic layers 1.0 summed absorption of unity corresponds 0.8 0.6 Polyethylene layers to total absorption of the LE and HE beam 0.4 in the material. 0.2 dry sand 0.0 0.0 0.2 0.4 0.6 0.8 1.0 LE + HE beam absorption Validation trial March 2006 y = 1.015x - 1.396 100 R2 = 0.997 90 Fig.4 Meat measurement in meat boxes using Eagle FA 80 A sample DEXA, Eltham New Zealand 70 Linear (A sample) 60 2007 R.W. Purchas, R. Archibald, J.G. West., C.M. Bartle. ‘An evaluation of the EagleTM FA DEXA (Dual energy 50 X-ray absorpiometry) scanner as a method of estimating the chemical lean in cartons 50 60 70 80 90 100 of boneless beef’, Food New Zealand, February/March issue. Laboratory 1
EAGLE FA Meat Scanning SystemMeasures fat content of meat (100 – fatpercentage equals the chemical leanpercentage) Fig.5 Meat measurement in bulk meat system based on DEXA. Food NZ Feb/Mar 2007
Kiwi ingenuity praised as Innovators Awards 2011 finalists revealed By Esther Goh, September 13, 2011 @ 12:10 pm From nanofibres to bio-pesticides and magnetic resonance, a handful of companies and individuals have been named the best that Kiwi ingenuity has to offer as finalists in the 2011 New Zealand Innovators Awards.Manufacturing:Doyle Sails NZ Ltd - Stratis Ice: a new super-light, super-strong sail membrane fabric Team names:currently on trial in the America’s Cup – aninternational first for a New Zealand Rob Archibald ANZCO Foodsmanufactured fabric. Murray Bartle GNS Science John West “Meatvision Ltd - The Eagle FA: X-ray technology Joe Manning “and specialised software that scans meat Graham Clarke “batches within the processing chain to Wayne Fergus ANZCO Foodsdetermine fat content. Matt Gorton “ Brian Dougan “EnaSolar - Solar Inverter: a range of solar Jamie Skinner “inverters for the global market with built in wi-fi and statistics package for tracking data.
C. Other Dual Beam systemsIAEA New Zealand Contributions to Security and Industrial Applications.IAEA Asia PacificDEXA – dual energy and x-ray absorptionNEUGAT – neutron and gamma-ray transmissionNEUDEG – neutron and dual energy gamma ray (transmission)
International Atomic Energy Meetings 2005 - 2009The NZ Representative at IAEA Co-operative Research Programme Meetings, Technical meetings (Vienna) and RCA (Regional Co-operative Agreement MeetingsAsia Pacific region); 1995-2000 and 2005-2010•1st Research Co-ordinated Meeting on Neutron-based Techniques for the Detection of Illicit Materials and Explosives, Vienna, Austria, 19-21 April, 2006 ‘Low costmethods of detecting illicit materials and explosives’. C Murray Bartle and William Stephenson, GNS Science, PO Box 31312, Lower Hutt, New Zealand•1st Technical Meeting on Combined Devices for Humanitarian Demining and Explosive Detection, Padua, Italy, 13-17 November, 2006.‘Advances of Industrial Dualbeam X-rays scanners and improved methods for detection of explosives and humanitarian demining’. C Murray Bartle, Chris Kröger, William Stephenson and JohnG West, National Isotope Centre, GNS Science, PO Box 31312, Lower Hutt, New Zealand•2nd Research Co-ordinated Meeting on Neutron-based Techniques for the Detection of Illicit Materials and Explosives, Mumbai, India, 12-16 November, 2007.‘Developing Low Cost Systems for the Detection of Threat Materials’, C Murray Bartle, Chris Kröger and William Stephenson, National Isotope Centre, GNS Science,PO Box 31312, Lower Hutt, New Zealand•2nd Technical Meeting on Combined Devices for Humanitarian Demining and Explosive Detection, Vienna, Austria, 26-30 November, 2007. ‘Utilising Advances inIndustrial Dual Beam X-ray Scanners to create New Capabilities in Humanitarian Demining and Explosive detection’. C Murray Bartle, Chris Kröger, and WilliamStephenson, GNS Science, PO Box 31312, Lower Hutt, New Zealand.•3rd Research Co-ordinated Meeting on Neutron-based Techniques for the Detection of Illicit Materials and Explosives, Johannesburg,South Africa, November, 2009 ‘Developing Low Cost Systems for the Detection of Threat Materials’, C Murray Bartle and WilliamStephenson, National Isotope Centre, GNS Science, PO Box 31312, Lower Hutt, New Zealand.IAEA RCA Asia Pacific•IAEA/RCA Regional Training Course on Off-belt Analysis of Metalliferous Ores and Cement Quality by NAS, 13-17 October 2008, Beijing, China. ‘Country Report forNew Zealand’, C Murray Bartle, Bernard Barry and Frank Bruhn, GNS Science, P.O. Box 31312, Lower Hutt, New Zealand. IAEA/RCA meeting Bangkok March 2009: Summarising old programme ‘Raising Productivity in the Coal, Mineral and Petrochemical Industries By using Nucleonic Analysis Systems and Radiotracers (RAS/8/107)’ and commence new programme ‘Diagnosing Industrial Multiphase Systems by Process Visualization using Radiotracers and Sealed Sources. •IAEA/RCA meeting and Beijing May 2010 AGM on New Developments and Adoption of Protocols and Procedures for Industrial Radiotracer and Sealed Source Technology China, Beijing May 2010. •IAEA Expert missions November/December 2010.
IAEA Group Asia Pacific Bangkok 2009 http://penguingrove.com Diagnosing Industrial Multiphase Systems by Process Visualization using Radiotracers and Sealed Sources (RCA) 2009 -2012
AGM on New Developments and Adoption of Protocols and Procedures for Industrial Radiotracer and Sealed Source Technology, Beijing, China, 17- 21 May 2010Protocols on Interwell tracer Quang (VIE), Gao (CPR)Protocols on Column scan Jaafar (MAL), Siripone (THA)Protocols on Leak detection, H.E. Sharma (India), Sugiharto (INS)Protocols on Maintenance & Calibration Khan (PAK), Kasige (SRI)Concept paper for TC project 2012-2013 Jung (ROK), Bartle (NZL)
D. Simultaneous fast neutron and dual energy gamma ray transmission from a 252Cfsource (NEUDEG) http://www-naweb.iaea.org/napc/physics/meetings/3rd-RCM-NBT/Presentations/Bartle.pdf NEUDEG LAYOUT Tank water source conveyor ^ 0.4m 0.25m Test material Plastic organic scintillator deployable Pb filter 4.5 mm thick 1. Create two beams by making measurements by processing the total beam with and without a filter similar to what is done with x-rays DEXA machines. 2. NO PSD required and use is made of a plastic organic scintillator.
1. Based on a dual beam fast neutron and gamma ray system. Makes use of asimple physical filtering system like DEXA but avoids use of expensive and difficult-to-applyelectronics used in NEUGAT like pulse-shape-discrimination (PSD). Good functionality isobtained without having to completely separate the fast neutrons and the gamma rays intotwo beams.2. The detector media is low cost plastic scintillator which can be easily machined andassembled into large systems if required.3. The electronics is reduced to a simple discriminator and counting system. This is low costand reliable and in principle can be operated from a portable computer.4. Systems are inherently portable.5. Most countries have 252Cf sources for other applications such as PGNAAso new methodologies using this source are often practical and extends the applicationsof existing sources.
NEUDEG SYSTEM (Difference in absorption : without Pb filter - difference without filter with Pb filter) v (sum of absorptions) 1.2 Poly layers - with Pb filter 0.8 acrylic layers NEUDEG 0.4 water layers sand layers 0.0 0.0 0.2 0.4 0.6 0.8 1.0 -0.4 sum absorptions with + without Pb filterhttp://www-naweb.iaea.org/napc/physics/meetings/3rd-RCM-NBT/Presentations/Bartle.pdf DEXA - Banana curves 1.6 Acrylic + aluminium LE - HE beam absorption c.f. DEXA 1.4 1.2 layers Acrylic layers 1.0 0.8 0.6 Polyethylene layers 0.4 0.2 dry sand 0.0 0.0 0.2 0.4 0.6 0.8 1.0 LE + HE beam absorption
Application of a NEUDEG System used in the reverse sense.‘An Efficient Directional Fast Neutron Sensor for a Mixed Radiation Field.’Radiation Measurements in press, C.M. Bartle and G.V.M. Williams.www.sciencedirect.com/science/journal/aip/135044871. Detects fast neutrons in a mixed radiation field2. Directional detector as only the fast neutrons and gamma rays passing through the filtering system contribute to the calculation, other radiations being subtracted out.Uses of directional detectors of fast neutrons in a mixed radiation field;1. Controlled fusion neutron imaging (Igushi etal., 2001),2. Nuclear fuel safety research (Kaneko et al., 1997),3. Imaging of solar neutrons and detecting special nuclear materials (SNMs) (Bom, 2009; Bowden et al., 2009; Braver etal., 2006; Srikrishna, Chari and Tisch, 2005)4. Variety of applications in nuclear science (Yamanishi, 2005).Bowden (2009 estimates) that the reduction of background through use of adirectional fast neutron detector could increase the detection range of some specialnuclear materials from 7 m to 70 m.
Summary: NEUDEG systems in development1. Use of a simple physical filtering system (like DEXA approach for x-rays) but applied toa Cf-252 source defines two useful beams for product assessments and avoids useof expensive and industrially unproven electronics needed for NEUGAT e.g. avoids pulseshape discrimination (PSD) electronics. Good functionality is obtained without having tocompletely separate the fast neutrons and the gamma rays in the two beams. Effectivelythe electronics is reduced to a simple discriminator and counting system that in principle canbe operated from a portable computer.2. The detector media is low cost plastic scintillator which can be easily machined andassembled into large systems if required.3. Systems are inherently portable.4. Most countries have 252Cf sources for other applications such as PNGNAA (promptneutron gamma neutron activation analysis . New methodologies using this sourceextends the value of the investment in this source.