Advances in Gamma-Ray Detection and Imaging
Submitting Institution
University of SouthamptonUnit of Assessment
PhysicsSummary Impact Type
TechnologicalResearch Subject Area(s)
Physical Sciences: Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences
Summary of the impact
The University of Southampton's distinguished body of work on the design
of technology for gamma-ray detection and imaging has informed new
counter-terrorism practices. Technological advances arising from the
research have been crucial to delivering significant benefits in the
fields of homeland security and nuclear safety — the latter particularly
in the wake of the 2011 Fukushima disaster. A spin-out company, Symetrica,
currently employs 26 people in the UK and the USA, has a forecast turnover
of more than £10 million for 2013-14 and has been recognised as an example
of best practice. It is a technological leader in the field of radioactive
isotope identification.
Underpinning research
Research into designing technology for gamma-ray detection and imaging
began in the University of Southampton's Astronomy Group in the 1980s and
continued throughout the next two decades, underpinning the formation of
spin-out company Symetrica Ltd in 2002. Symetrica's core technologies
resulted from a combination of the research activities carried out within
the group and specifically within the teams working in instrument design
and construction.
Dr Tony Bird, Reader in the School of Physics and Astronomy
(1987-present), led the advancement of small low-power
scintillator-photodiode radiation detectors for the development programme
of the European Space Agency's (ESA) INTEGRAL space telescope [3.1, G1,
G2]. The International Gamma-Ray Astrophysics Laboratory is the most
sensitive gamma-ray observatory to date and, through the analysis of
gamma-ray bursts in space, aims to solve some of astronomy's biggest
mysteries.
As a postdoctoral researcher, Bird optimised the design of gamma-ray
detectors, creating a technology (paper published in 1993) that was more
cost-effective and robust than existing detectors (standard NaI(Tl)/PMT
combinations) and, crucially, did not require a high-voltage supply that
might cause equipment failure in space. These sensitive radiation
detectors paved the way for highly segmented 2D gamma-ray detector arrays,
which can provide high-resolution spectroscopy as well as imaging
capability.
Essential gamma-ray imaging technologies were developed [G1, G2] by teams
led by Professor A Dean, now a Professor Emeritus within the Astronomy
Group following his retirement in 2009, and Dr D Ramsden, who retired in
1996 and founded Symetrica in 2002, where he is now chief technical
officer and head of research. The resulting imaging systems relied on the
temporal or spatial modulation of the incident gamma-ray flux using high-Z
materials and produced images of far higher quality than previously
possible. These systems are now ubiquitous in high-energy imaging systems
for space astronomy and also form the basis for `stand-off imaging' (i.e.
from distance) in homeland security and nuclear industry applications
[3.2, 3.3, G3].
Led by Dr Fan Lei, a postdoctoral researcher at the time (left
Southampton in 2000), research into instrument modelling guided the
INTEGRAL Mass Model project [3.4, G5] an independent and uniform
instrument and spacecraft modelling program for ESA. Using data on mass
distribution and chemical composition of material in the instruments, Dr
Lei formed a Monte Carlo model of the whole payload to assess the
performance of each instrument and identify any flaws. It was the first
time simulations had provided detailed and useful satellite design input.
Simulations were used to optimise the response of the detectors to gamma
rays, inform the calibration strategy and support data analysis after
launch. Simulations were also used in designing the detector geometry to
ensure high and uniform light collection from the scintillation counters,
producing the best possible spectral resolution.
Research into spectral response modelling through signal processing and
mathematical modelling led to some of Symetrica's core technology for
isotope identification [3.5, 3.6]. These methods allow a detector spectrum
to be deconvolved into the component isotope signatures, enabling accurate
identification and quantification of radioactive materials.
The combination of these technologies provided Symetrica with an initial
portfolio of radiation detection products and continues to inform the
company's development of innovative radiation detection solutions.
References to the research
Outputs (the best 3 illustrating quality of work are starred)
*3.1 Bird, A. J.; Carter, T.; Dean, A. J.; Ramsden, D.; Swinyard, B. M.,
The optimisation of small CsI(Tl) gamma-ray detectors, IEEE
Transactions on Nuclear Science, vol. 40, issue 4, pp. 395-399, 1993.
*3.2 Durrant, PT; Dallimore, M; Jupp, ID; Ramsden, D., 1999. The
application of pinhole and coded aperture imaging in the nuclear
environment, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION
A, Vol 422, p667-671
3.3 Ramsden, D; Bird, AJ; Palmer, MJ; Durrant, PJ, 1996, Gamma-ray
imaging systems for the nuclear environment, NUCLEAR ENERGY-JOURNAL OF THE
BRITISH NUCLEAR ENERGY SOCIETY, Vol 35, p353-359.
3.4 Lei, F.; Ferguson, C.; Bird, A. J.; Lockley, J. J.; Dean, A. J., The
Integral Mass Model — Timm, Astrophysical Letters and
Communications, Vol. 39, p.373, 1999
*3.5 Meng, LJ; Ramsden, D, An inter-comparison of three
spectral-deconvolution algorithms for gamma-ray spectroscopy, 2000,
IEEE Transactions on Nuclear Science, Vol 47, Part 1, p1329-1336
3.6 Meng, LJ; Ramsden, D; Chirkin, VM; Potapov, VN; Ivanov, OP; Ignatov,
SM, 2002, The design and performance of a large-volume spherical CsI(Tl)
scintillation counter for gamma-ray spectroscopy, NUCLEAR INSTRUMENTS
& METHODS IN PHYSICS RESEARCH SECTION A, Vol 485, p 468-476.
Grants supporting the underpinning research:
G1. SERC; GR/H93729; £56,328; 01/04/1993-31/03/1994; "Gamma-ray
astrophysics"; PI: A J Dean
G2. SERC; GR/J63040; £277,290; 01/01/1994-30/06/1995; "Gamma-ray
astronomy with INTEGRAL"; PIs: A J Dean, D Ramsden
G3. PPARC; GR/K41960; £47,838; 01/11/1994-31/10/1995; "Gamma-ray imager
for the disordered nuclear environment"; PI: A J Dean
G4. PPARC; GR/K94867; £701,493; 01/11/1995-31/12/2002; "Southampton
participation in INTEGRAL imager software"; PI: A J Dean
G5. PPARC; PPA/G/R/2002/00466; £454,158; 01/01/2003-31/03/2005; "UK in
INTEGRAL: calibration, mass modelling and core science"; PI: A J Dean
Details of the impact
Research by the University of Southampton's Astronomy Group has gone
beyond solving galactic riddles, radically improving the capability of
security agencies to detect dirty bomb threats and contributing to tighter
safety procedures in the nuclear industry.
Responding to US government calls for technology that could be used at
ports to detect suspect radioactive materials, spin-out company Symetrica
[5.1] set out to adapt the Southampton team's original gamma-ray detector,
which had performed successfully in space exploration. Existing detection
systems, housed in `portals', were unable to discriminate between
different threat and natural radiation sources. Symetrica developed its
original gamma-ray detector — its spectroscopic capabilities enable it to
distinguish different radiation sources and accurately identify threat
materials hidden in heavily shielded containers — to make a system that
could be used in a portal and in a handheld detector as a second layer of
surveillance.
In 2006 Symetrica partnered with Smiths Detection, a world-leading
provider of detection systems for X-rays, explosives and traces of
radioactive materials, which led to a $222m contract from the US
Department of Homeland Security's (DHS) Domestic Nuclear Detection Office
(DNDO) to develop next-generation radiation detection and identification
systems. This move was crucial in giving Symetrica access to the key US
government market. In September 2008 Smiths Detection announced the launch
of the partnership's High Performance Radioisotope Identifier (HPRID), a
next-generation handheld device for detecting and identifying highly
enriched uranium, plutonium and other radioactive materials. A choice of
either a NaI or LaBr3 crystal and a neutron detector identify
and analyse the specific potential threat. The HPRID was based on
Symetrica's original Discovery™ technology for isotope detection and
identification.
The collaboration between Symetrica and Smiths led to further success in
2011 when their RadSeeker handheld radioisotope identifier, which
superseded the HPRID, was approved by the DHS's DNDO as its primary
radiological handheld detector device [5.2, 5.3] to help port and border
personnel evaluate cargo, containers and vehicles as part of the US
government's counter-terrorism efforts.
Smiths received an initial production order for $4.5m in May 2011, built
around Symetrica's key isotope identification and spectrum stabilisation
technologies employed in this device. In 2012, the DHS announced the
purchase of RadSeeker DL instruments for $8.3m. As a result of this
decision, Symetrica's technology was deployed by the Honolulu Emergency
Services Department, through US Government grant funding, to screen
tsunami debris as it reached Hawaii in the aftermath of the Fukushima
disaster [5.4].
Symetrica has grown into an international company with 26 employees in
the UK and the USA — a number that is expected to grow by 30% in 2013-2014
with RadSeeker entering full production. Its forecast turnover is £10m.
Symetrica Inc, a wholly-owned subsidiary of Symetrica Ltd, was founded in
the USA, with a manufacturing and testing facility in Maynard, MA.
Symetrica has a strong R&D programme in the UK itself, and has funded
PhD studentships at the Universities of Southampton and Surrey. It has
also successfully bid for more than £100k of DTI/EPSRC funding on the
basis of collaborative research with the University of Southampton [5.5,
5.6].
Symetrica's shift in market focus from space to security is the key to
its current success and is attributable to a decision taken by commercial
advisers at SETsquared, an organisation that supports spin-outs from the
five universities of Southampton, Exeter, Bristol, Bath and Surrey.
SETsquared matched the Southampton astronomy team with a mentor, Heddwyn
Davies, now the chief executive of Symetrica, who targeted the security
sector as Symetrica's primary market.
Symetrica's Homeland Security portfolio now includes scalable, 3He-free
neutron detectors, inexpensive Radiation Portal Monitors (RPMs) that can
reduce nuisance alarms alarm rates during cargo screening and RPMs
equipped with crystal spectrometers that provide a greatly enhanced
isotope-identification capability. With all three of these technologies
entered into the European Illicit Trafficking Radiation Assessment Program
(ITRAP+10), Symetrica's footprint on the Homeland Security Market has
significantly increased. A prototype portal monitor, trialled at the Port
of Felixstowe, demonstrated its effectiveness in distinguishing naturally
occurring radioactive materials from potential threat materials. The trial
system reduced the number of manual secondary inspections of cargo by
customs personnel at the port by ~80%.
Already partnered with Smith's detection, Symetrica is now in discussions
with two other market-leading prime contractors who wish to use their
technology.
The story behind the Symetrica spin-out was highlighted as an example of
best practice by The Engineer magazine in 2011 [5.7], and in
February 2012 the Duke of York visited Symetrica's headquarters at the
University's Science Park, to learn how its technology is winning export
sales for the UK [5.8].
Symetrica continues to be research-active and has filed 15 patents since
its launch. There is a programme of continued collaboration between the
School of Physics and Astronomy and Symetrica in the field of detector
development. Funded studentships, supervised by Bird, were completed in
2009 and 2011 and the findings fed into products now offered by Symetrica.
The first student (Dr C Burt) carried out the initial development for
large area PVT detectors to act as low-cost replacements for traditional
scintillation counters. The second student (Dr M Foster) worked on
extending these detectors in the search for a replacement for Helium-3
neutron detectors and is now a Symetrica employee in their research
department. Both these developments are now marketed as components within
the Symetrica Radiation Portal Monitor (RPM) range, which offer a >75%
nuisance alarm reduction and improved isotope identification capability
compared to other available systems.
Sources to corroborate the impact
5.1 www.symetrica.com (general
information on company and products)
5.2 http://uk.reuters.com/article/2011/08/10/idUS175245+10-Aug-2011+BW20110810
(DNDO approve RadSeeker as its primary radiological handheld device)
5.3 http://www.smithsdetection.com/RadSeeker.php
(Smiths Detection deploy Symetrica Discovery™ technology in their latest
RadSeeker handheld isotope identifier, Aug 2011)
5.4 http://www.kitv.com/news/hawaii/Advanced-radiation-detector-to-scan-debris-from-Japan/-/8905354/16711292/-/149om70/-/index.html
(Media coverage of RadSeeker screening tsunami debris)
5.5 http://thebln.com/2011/05/how-the-technology-strategy-board-spent-635-million-company-by-company/
(reports TSB grant of £106,319 to Symetrica)
5.6 Grant — PI: A J Bird, "New photo-detection technology for possible
use in sensors for Homeland Security", EPSRC (DTI/EPSRC joint funding),
10/7/2007 - 10/1/2009, £10500 (this was supported by DTI/TSB funding
direct to Symetrica for the joint project)
5.7 http://www.theengineer.co.uk/in-depth/analysis/spin-doctors/1009205.article/
(identifies Symetrica as a successful spin-out)
5.8 http://www.symetrica.com/news/2012/2012_02_07_1.php
(Duke of York meets Dr Ramsden of Symetrica). For verification of
Symetrica sales figures, contact: Chief Technical Officer, Symetrica Ltd