Research 15: M Bartle

1. Combined Fast Neutron and Dual Energy Gamma
Ray 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.

2. 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

3. DUAL BEAM TRANSMISSION PRINCIPLE
Incident γ-ray beam
Transmitted beam
Transmitted beam
Detector
Incident neutron beam
product

4. Measurement of Meat Fat Content
hydrogen carbon nitrogen oxygen n(H) per EAN
wt% wt% wt% wt% gm
LEAN 10 10 3 77 6.15 x 1022 7.64*
(approx)
FAT 15 74 0 11 9.05 x 1022 5.83
* includes minerals

6. 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

8. Fig. 6. The NEUGAT system called ‘Phoebe’ based on a 252Cf source and a 6 litre
organic liquid scintillation detector. The source is mounted in the top tank filled with
water and the detector is mounted under the conveyor. Neutron and gamma ray events are
separated by pulse shape discrimination.

9. 60
LOW AND HIGH DENSITY WOOD CHIPS
NEUGAT 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%)

10. 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.

11. 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.

12. 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 by
number 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).

13. AA=LOW energy detector
CC
BB=filter
CC=HIGH energy detector
AA
BB
Basic components of a dual energy detector element

14. 30000
Aluminium (Al) Z=13
25000
glass-based scintillators
Difference 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)

15. DEXA Absorption Curves
1.6
Fig.3 DEXA absorption curves for with a range
of atomic numbers (elements) or effective
LE - 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

16. EAGLE FA Meat Scanning System
Measures fat content of meat (100 – fat
percentage equals the chemical lean
percentage)
Fig.5 Meat measurement in bulk meat system based on DEXA.
Food NZ Feb/Mar 2007

18. 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 – an
international first for a New Zealand Rob Archibald ANZCO Foods
manufactured 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 Foods
determine 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.

19. C. Other Dual Beam systems
IAEA New Zealand Contributions to Security and Industrial Applications.
IAEA Asia Pacific
DEXA – dual energy and x-ray absorption
NEUGAT – neutron and gamma-ray transmission
NEUDEG – neutron and dual energy gamma ray
(transmission)

20. International Atomic Energy Meetings 2005 - 2009
The NZ Representative at IAEA Co-operative Research Programme Meetings, Technical meetings (Vienna) and RCA (Regional Co-operative Agreement Meetings
Asia 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 cost
methods 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 Dual
beam X-rays scanners and improved methods for detection of explosives and humanitarian demining’. C Murray Bartle, Chris Kröger, William Stephenson and John
G 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 in
Industrial Dual Beam X-ray Scanners to create New Capabilities in Humanitarian Demining and Explosive detection’. C Murray Bartle, Chris Kröger, and William
Stephenson, 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 William
Stephenson, 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 for
New 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.

21. IAEA Group Asia Pacific Bangkok 2009 http://penguingrove.com
Diagnosing Industrial Multiphase Systems by
Process Visualization using Radiotracers and
Sealed Sources (RCA) 2009 -2012

22. AGM on New Developments and Adoption of Protocols and Procedures for Industrial Radiotracer
and Sealed Source Technology, Beijing, China, 17- 21 May 2010
Protocols 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)

23. D. Simultaneous fast neutron and dual energy gamma ray transmission from a 252Cf
source (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.

24. 1. Based on a dual beam fast neutron and gamma ray system. Makes use of a
simple physical filtering system like DEXA but avoids use of expensive and difficult-to-apply
electronics used in NEUGAT like pulse-shape-discrimination (PSD). Good functionality is
obtained without having to completely separate the fast neutrons and the gamma rays into
two beams.
2. The detector media is low cost plastic scintillator which can be easily machined and
assembled into large systems if required.
3. The electronics is reduced to a simple discriminator and counting system. This is low cost
and 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 PGNAA
so new methodologies using this source are often practical and extends the applications
of existing sources.

25. 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 filter
http://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

26. 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/13504487
1. Detects fast neutrons in a mixed radiation field
2. 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 a
directional fast neutron detector could increase the detection range of some special
nuclear materials from 7 m to 70 m.

27. Summary: NEUDEG systems in development
1. Use of a simple physical filtering system (like DEXA approach for x-rays) but applied to
a Cf-252 source defines two useful beams for product assessments and avoids use
of expensive and industrially unproven electronics needed for NEUGAT e.g. avoids pulse
shape discrimination (PSD) electronics. Good functionality is obtained without having to
completely separate the fast neutrons and the gamma rays in the two beams. Effectively
the electronics is reduced to a simple discriminator and counting system that in principle can
be operated from a portable computer.
2. The detector media is low cost plastic scintillator which can be easily machined and
assembled into large systems if required.
3. Systems are inherently portable.
4. Most countries have 252Cf sources for other applications such as PNGNAA (prompt
neutron gamma neutron activation analysis . New methodologies using this source
extends the value of the investment in this source.