Supporting e2v Ltd. in developing capability as a supplier for major space science missions
Submitting InstitutionUniversity College London
Unit of AssessmentPhysics
Summary Impact TypeTechnological
Research Subject Area(s)
Physical Sciences: Atomic, Molecular, Nuclear, Particle and Plasma Physics
Technology: Communications Technologies
Summary of the impact
Research conducted within the Department of Space and Climate Physics at
UCL has had a significant impact upon e2v Ltd., a manufacturer of
charge-coupled devices (CCDs). Through working collaboratively with e2v,
UCL has helped the company to secure major contracts and business [text
removed for publication]. This includes two contracts for the supply of
CCDs for the European Space Agency (ESA) missions Gaia (€20 million) and
Euclid (€10 million). Furthermore, the symbiotic relationship has
contributed to the establishment of e2v as Europe's leading supplier of
high-quality CCDs for space science applications and has underpinned an
improved understanding of device design and optimisation within the
The Department of Space and Climate Physics (also known as the Mullard
Space Science Laboratory, or MSSL) at UCL includes an Instrument Science
Group that develops high-specification cameras for use on scientific
spacecraft and undertakes fundamental research in the field of imaging
sensors, including CCDs. CCDs are optical sensors that take the form of a
two-dimensional pixelated array. They have revolutionised the acquisition
of image information; for example, modern digital cameras are based on
devices of this kind. The success of scientific applications is often
critically dependent on the precise response of CCDs in their expected
environment; for space science applications, this environment is a
satellite operating in the harsh conditions of space.
Since 1995, the MSSL group has worked closely with CCD manufacturer e2v
Ltd. on a programme of CCD characterisation and modelling [1-6]. This
partnership typically involves the detailed design and manufacture of CCDs
by e2v, followed by the scientific evaluation and characterisation of the
devices in specialist facilities at MSSL. This characterisation is within
the context of performance and process models, and includes aspects such
as noise sources and electron mobility, diffusion and loss. Test data are
simulated and interpreted to quantify underlying device properties, and
device performance is estimated. The models that are used have been either
developed at MSSL or adapted from those in the published literature. The
results and evaluations from the research at MSSL then go on to inform
e2v's next generation of devices and their optimal use. The programme has
so far involved the characterisation of more than 250 of e2v's CCDs.
The collaborative studies function within a virtuous circle, in which
research insights relating to the improvement of CCDs are shared, and
understanding builds from project to project. Insights that have resulted
from the programme of research are in areas including the physical
processes of the devices, such as electron mobility and diffusion, noise
sources, linearity, electron loss mechanisms, sensitivity, temperature
dependence and set voltage dependence; camera design optimisation; device
specification; and CCD data interpretation (calibration) during data
analysis. For example, the MSSL group showed how linearity of response
could be increased beyond full-well capacity through pixel integration,
and the point spread function dependency on wavelength gave insight into
the electron diffusion in the drift region of the CCDs.
Much of this CCD research was conducted as part of studies of future
space mission concepts, of which there are many more than actual space
missions, due to the way that technical risk is mitigated and selections
are made. Such studies are very comprehensive and are often competitive
against other mission concepts. These collaborative CCD studies were
conducted between 1996 and 2002 for the space mission Integral, which was
launched in 2002 [1, 2]; in 1999 and 2000 for the GOES Solar X-ray Imager
(SXI) ; in the early 2000s for the planned space mission Eddington [4,
5]; in the mid 2000s for the FPP (Focal Plane Package) and EIS
(Extreme-Ultraviolet Imaging Spectrometer)  instruments on the space
mission Hinode, which was launched in 2006; from the late 2000s to the
present time for the current space missions Gaia and Euclid; and for a
number of other space missions. Often a customer that was an expert in
detector technology was also involved, working with MSSL to optimise
mission performance (for example, Lockheed Martin for GOES SXI  and
Hinode FPP; and ESA for Eddington [4, 5], Euclid and Gaia).
For actual flight missions the emphasis was on device specification,
device characterisation, identifying optimal operating conditions,
screening and preparation for exploitation. Important developments that
have formed part of this work include the examination of back illumination
in CCDs that had been thinned to create extreme ultraviolet sensitivity,
and the evaluation of novel concept L3CCDs (a new type of CCD) as a
potential mission device for Gaia.
The table below lists a number of studies that MSSL has been involved
with and that have led to improved understanding of CCDs.
|Number of CCDs
|Integral flight camera
|European Space Agency contract
|References  and .
|Lockheed Martin (US) contract
|Multiple satellites in the GOES series. Reference .
|Lockheed Martin (US) contract
|Direct result of GOES SXI project.
|References  and .
|ESA and STFC grant
|around 150 (including all flight devices)
|Helped secure Gaia selection as an ESA mission.
|UK Space Agency grant
|Followed Eddington study. Several initial devices manufactured for
ESA. Prototype readout electronics designed and built at MSSL. MSSL
contributed to the devices’ specification.
|ESA and STFC
|5 to date
|Helped secure Euclid selection as an ESA mission.
|Part of the evaluation of a novel far UV spectral imager that flew
on a sounding rocket.
|Back illuminated CCDs 2003
|Enhanced the group’s understanding of a particular device
configuration: charge diffusion and point spread function in
|L3CCDs for Gaia 2004-2005
|Part of Gaia pre-selection evaluation.
Key UCL researchers: Alan Smith (Head of Detector Physics group
1990-2005; Head of Department 2005-present; Professor of Detector Physics
1998-present) and Dave Walton (Research Fellow 1990-present; Head of
Photon Detection Systems group 2006-present).
References to the research
 The CCD and readout electronics for the OMC instrument on Integral,
D. M. Walton, P. D. Thomas, J. L. Culhane, B. Jordan, A. Smith, A. P.
Dibbens and L. J. Bradley, Astronomy and Astrophysics, 411,
L275-L279 (2003) doi:10.1051/0004-6361:20031453
 OMC: An Optical Monitoring Camera for INTEGRAL — Instrument
description and performance, J. M. Mas-Hesse, A. Smith, et. al, Astronomy
and Astrophysics, 411, L261-L268 (2003) doi:10.1051/0004-6361:20031418
 Characterization of the flight CCD detectors for the GOES N and O
Solar X-ray Imagers, R. A. Stern, L. Shing, P. Catura, M. Morrison, D.
Duncan, J. R. Lemen, T. Eaton, P. Pool, R. Steward, D. Walton and A.
Smith, Proceedings of SPIE, 5171, 77-88 (2004) doi:10.1117/12.506346
 CCD issues for Eddington, D. M. Walton, A. Smith and M. S.
Cropper, In: Proceedings of the First Eddington Workshop on Stellar
Structure and Habitable Planet Finding, F. Favata, I. W. Roxburgh
and A. Gimenez (eds.), ESA SP-485, 211 (2002) — pdf available at: http://adsabs.harvard.edu/abs/2002ESASP.485..211W
 A high stability multi-CCD focal plane for ESA imaging missions, D.
M. Walton, P. M, Bonhomme, R. P. Card, G. P. Davison, P. R. Guttridge, M.
R. Hailey, H. Lamoureux, K. J. Rees, A. D. Rousseau, P. D. Thomas, B.
Winter and N. R. Waltham, Nuclear Instruments and Methods in Physics
Research Section A, 573, 253-256 (2007) doi:10.1016/j.nima.2006.10.260
 The EUV Imaging Spectrometer for Hinode, J. L. Culhane, L. K. Harra,
A. M. James, K. Al-Janabi, L. J. Bradley, R. A. Chaudry, K. Rees, J. A.
Tandy, P. Thomas, M. C. R. Whillock, B. Winter, G. A. Doschek, C. M.
Korendyke, C. M. Brown, S. Myers, J. Mariska, J. Seely, J. Lang, B. J.
Kent, B. M. Shaughnessy, P. R. Young, G. M. Simnett, C. M. Castelli, S.
Mahmoud, H. Mapson-Menard, B. J. Probyn, R. J. Thomas, J. Davila, K. Dere,
D. Windt, J. Shea, R. Hagood, R. Moye, H. Hara, T. Watanabe, K. Matsuzaki,
T. Kosugi, V. Hansteen and Ø. Wikstol, Solar Physics, 243, 19-61
References ,  and  best indicate the quality of the
Details of the impact
The primary beneficiary of the research described in section 2 is MSSL's
collaborator on much of the work: e2v Ltd. e2v is a UK company that
develops a range of innovative technologies including CCDs. It employs
1,600 people, roughly a third of whom are scientists and engineers, and
has annual sales of around $370 million. The MSSL research has underpinned
improved performance of e2v within the REF impact period; it has enabled
the company to win major contracts, led to improvements in its CCD
technology, and enhanced its standing in the space market. e2v's Chief
Engineer (Imaging Applications) confirmed the importance of UCL's work to
the company: "the e2v relationship with MSSL and UCL has been one of the
foundations of our space science imaging business" [A].
The development of new generations of CCDs is an expensive affair,
costing millions of pounds, yet cannot be left to chance once a future
space programme is selected. e2v tends to undertake new device
developments under contract from customer organisations (rather than fund
such developments fully themselves). Prior to selection it is necessary to
first demonstrate the science performance and reliability of devices.
MSSL's engagement with e2v and assistance in areas such as this — in
addition to their joint research with e2v on prior space missions — has
enabled the company to secure two major contracts with ESA that have been
active within the REF impact period: a €20 million contract (2007 to 2011)
for the supply of CCDs for the Gaia mission, due to be launched in late
2013; and a €10 million contract (2012 to 2016) for the supply of CCDs for
the visible (VIS) instrument on the Euclid mission, due to be launched in
2020 [A]. Gaia and Euclid will include the largest and second largest CCD
focal planes ever built for space, with 109 and 36 CCDs respectively. The
success of both missions is critically dependent on the performance of the
CCDs, since their main data product is the output of these devices.
Interpretation of the CCD signals therefore delivers the primary mission
MSSL's engagement and work with e2v has also enhanced the company's
standing in the competitive space market, and has assisted them in
becoming Europe's dominant and preferred supplier of CCDs for space
science applications [B]. Indeed, the track record that the research has
helped e2v to secure is unrivalled. This enhanced reputation and improved
ability to secure contracts was recognised by the company's Chief
Engineer, who, speaking about the impact of the joint Gaia mission
research on the Euclid contract and other business activities, said: "The
supply of custom CCDs to the Gaia mission is still the largest space
contract that we have won [...] and the support of MSSL in making this
mission feasible is of course significant. The capability that this
experience has built at e2v now makes it possible for us to be a credible
supplier to the next ESA science missions. For example, we have recently
won a contract for €10M for supply of CCDs to the Euclid VIS instrument
[text removed for publication]" [A].
The influence of MSSL research on the success of e2v is further
emphasised by the Chief Engineer, who praises "the strong technical
liaison between yourselves and the Lockheed Martin Solar Physics group,
which enabled us to supply CCDs into several programmes from SXI on GOES,
to all of the Hinode instruments, the HMI and AIA instruments on the Solar
Dynamics Observatory, and has built both our experience and reputation for
Solar Imaging such that we have also been able to address other
opportunities such as IRIS (the Interface Region Imaging Spectrometer),
STEREO, and SUVI [text removed for publication]" [A]. This liaison
comprised collaborative CCD research and was manifest in part in a joint
publication (reference  in section 3).
In addition to enhancing e2v's reputation and helping them to secure
large contracts, the symbiotic relationship between the company and MSSL
has led to an improved understanding at e2v of mission science
requirements and their implications for CCD design. The Chief Engineer
said: "the insights that the MSSL team have brought to us on the mission
science requirements and how these translate into CCD performance needs
have enabled us to better understand how we can design and optimise our
detectors for particular applications. This insight has been invaluable in
allowing us to address other customers with similar requirements, being
able to offer solutions rather than simply asking questions. In this high
technology marketplace this is a very strong selling point." [A]
Sources to corroborate the impact
[A] Supporting statement from Chief Engineer (Imaging Applications, Space
Science and Astronomy Business) at e2v Ltd. — corroborates that MSSL
research helped e2v to win major contracts (including two with ESA worth a
total of €30 million), enhanced the company's reputation and ability to
secure contracts, and led to an improved understanding of device design
and optimisation. Available on request.
[B] ESA Study Scientist at European Space Research and Technology Centre
(ESTEC) can be contacted to corroborate the claim that MSSL research has
enhanced e2v's standing in the competitive space market and assisted them
in becoming Europe's dominant supplier of CCDs for space science
applications. Contact details provided separately.