The Societal Benefits of the U.S. International Linear
Collider Research and Development Program1
I.
Introduction
The International Linear Collider (ILC) project is a global, collaborative effort which represents
the consensus of the world-wide high energy physics community for the next major particle
accelerator facility: a linear accelerator capable of colliding positrons and electrons with centerof-mass energies of 500 GeV, eventually upgradeable to 1 TeV. Building the ILC will require
substantial advances in accelerator and detector science and technology that can only be
accomplished through significant world-wide investment in a coordinated R&D effort in the next
five years. While a global consensus has been reached by the high energy physics community on
the priority of the ILC in terms of fundamental scientific merit, the scale of the proposed effort is
such that any substantial national commitment will likely require further detailed consideration
of the potential wider impact of the R&D program.
Such an assessment needs to be undertaken with great care. Decision makers would like
realistic, quantitative assessments of both the risks2 and benefits of such a large program in the
context of a wider portfolio of R&D options in order to allow meaningful comparisons between
possible alternative courses of action. While such quantitative assessments can be reasonably
undertaken for short-term benefits and risks, the primary long-term wider impacts of curiosity
driven basic research programs are often indirect, and difficult or impossible to predict. For
example, relatively short-term technological spillovers or spinoffs that more or less directly
follow from investment in advanced radiofrequency (RF) technology needed for the ILC to
applications such as next generation light sources can be reasonably guessed at and quantified.
However, the much wider benefits that may follow from the use of such light sources across the
medical, biological and physical sciences are difficult to quantify, and even the existence of any
future applications of the basic understanding of physics at the Terascale is nearly impossible to
guess at. Recent history indicates that there is great danger in appearing to oversell the shortterm spillovers and ignoring the long-term wider benefits, which are central to societal and
economic arguments for undertaking high risk, high payoff basic science research. Nevertheless,
historical econometric studies on technological change have consistently shown that both direct
and indirect R&D spillovers of research are an important and fundamental source of
advancement, yielding high social rates of return.3 The challenge, then, is to find appropriate
narratives and/or quantitative metrics which are able to capture both the short-term and longterm benefits and risks of basic research in a balanced way so as to facilitate the decision-making
process.
1
Prepared by U. Varadarajan.
These risks may, for example, be associated with the probabilities and adverse impacts of failing to attain some
desired performance criteria in a required time period or within a forecast budget.
3
Leon Clarke, John Weyant and Alicia Birky, On the sources of technological change: Assessing the evidence,
Energy Economics, 2006, vol. 28, issue 5-6, p. 579-595.
2
1
Further, as basic science becomes a truly global endeavor whose fruits are available to scientists
internationally, the question of why the U.S. should invest in any given program rather than
allow Asia or Europe to spend its money also needs to be addressed. Any specific comparative
advantages that the U.S. may have in a given area or uniquely national benefits that may to
accrue from investment in a program also need to assessed.
The aim of the present document is to provide a narrative for the development of a detailed
assessment of the wider relevance of the U.S. ILC R&D program. Major components of the ILC
accelerator and detector R&D effort will be described, and a qualitative initial assessment is
made of their potential wider direct and indirect scientific and technological benefits, along with
any relevant national comparative advantages or international context. This will be followed by
a discussion of potential societal impacts that follow more broadly from investment in the ILC
R&D program, such as knowledge benefits, workforce development benefits and issues of
international cooperation. Finally, a sketch of the further information and analyses needed to
produce a more quantitative economic assessment is outlined.
II.
ILC R&D Program Scientific and Technological Benefits
The ILC R&D program is envisioned as a globally coordinated effort that will involve detailed
planning and a prioritization of needs. The bulk of this effort will be devoted to the accelerator
R&D program which will be coordinated as an integral part of the ILC Global Design Effort
(GDE). The direct, short to mid-term wider benefits of this accelerator R&D program arise
largely from the applicability of the scientific knowledge, technology and infrastructure being
developed for the ILC to a range of next-generation accelerator-based facilities. The novel
facilities enabled by this R&D effort in turn are expected to enable a myriad of potential, longerterm future applications in fields as diverse as medicine and nuclear waste. In addition, it is
expected that there will be indirect benefits or spillovers of the accelerator R&D program to nonaccelerator based technologies. An overview of the proposed ILC accelerator R&D program, the
novel facilities it is expected to help enable, as well as the potential for other indirect spillovers
will be discussed in detail in the first part of this section.
In addition to the accelerator R&D program, a more modest (and independently coordinated)
program will be devoted to detector R&D. The technologies required to attain the measurement
precision as well as the global data analysis infrastructures needed to extract the physics of the
Terascale from the collisions at the ILC are expected to have wider application. These issues
will be discussed in the latter part of this section.
A. Accelerator R&D
Creation of energetic particle beams enables much of modern research in the physical sciences.
Electrons, protons and atomic nuclei accelerated to high velocities serve as probes for studying
the broad range of matter from molecules and materials to quarks. The ILC will be able to
accelerate tightly focused beams of electrons and positrons to energies nearly an order of
magnitude higher than any previous machines. Collisions of these extremely high energy beams
will enable the study of the physical laws governing nature at the smallest distance scales, in the
2
hope of addressing fundamental questions such as the precise nature of dark matter and the
detailed physics of electroweak symmetry breaking and the Higgs field.
In order to produce the colliding beams necessary to precisely explore this new physics, the ILC
R&D program must make fundamental advances in accelerator science and technology. Many of
these advances – in areas such as superconducting radiofrequency (SCRF) science and
technology, high power RF power systems, polarized electron and positron sources, damping
rings, nanometer-scale beam instrumentation, large-scale alignment and metrology, as well as
accelerator simulations – will have substantial direct impacts on future accelerator based
facilities, as well as far ranging wider benefits. Further, the transfer of technology from
laboratory to industry is needed. After a description of each of these areas as well as the
advances required for the ILC, an assessment of the wider benefits of these advances is made,
focusing largely on their relevance to a range of novel next-generation accelerator-based
facilities. Finally, we discuss the international context of this R&D program, focusing on SCRF
technology.
Superconducting Radiofrequency (SCRF) Science and Technology
The ILC R&D program area focused on the superconducting radiofrequency (SCRF) science and
technology is both the area of highest priority and the most resource intensive, comprising more
than half of the accelerator R&D effort.
In all existing and planned accelerator facilities, beams are accelerated in evacuated tubes by the
powerful electric fields in traveling radiofrequency (RF) waves moving at the same speed as the
particles. In linear accelerators (linacs), these waves travel through a series of successive
cavities in synchrony with bunches of particles so as to constantly accelerate them as they move
along the linac. The main linac of the ILC will use cold superconducting radiofrequency cavities
powered by state of the art RF power sources to accelerate electrons and positrons. Older
accelerators used copper cavities and operated at room temperature. However, in order to
achieve the extremely high energies required to reach the Terascale in an accelerator of
reasonable length and cost, the ILC requires cavities which can support a very high ‘gradient’ or
energy gain per unit length measured in mega-electron volts per meter (MV/m). This could be
achieved by increasing both the frequency and RF power applied to a copper cavity.
Unfortunately, the resulting strong electric fields set up currents in the surface of a copper cavity
which dissipate energy and tend to cause electrical discharges which destroy the surface. One
way around these problems is offered by cooled superconducting cavities, where the tiny
resistance of the metal at RF frequencies virtually eliminates the currents and the heating,
resulting in much higher power efficiency. The superconductor of choice is ultra-pure niobium,
whose surfaces have been freed from inclusions, painstakingly polished, and cooled to just above
absolute zero by a liquid helium bath. Single-cell niobium cavities are formed into donut shapes
and welded into nine-cell units typically about one meter long. These units are processed
through a series of steps involving ultra-pure water rinses, high temperature baking, chemical
etching and electropolishing in a bath of highly reactive acids. Nine of the multi-cell units are
packaged into a single cryomodule which provides the enclosure for the helium bath. The ILC
will require approximately 2000 cryomodules containing 16,000 multi-cell units to produce
collisions at energies capable of probing the physics of the Terascale.
3
The U.S. ILC R&D effort will be focused on several challenges which need to be overcome in
order to make SCRF acceleration a viable technology within the capability of US industry. The
primary advantages of superconducting acceleration are realized by creating fairly high gradients
at lower frequencies of operation and high efficiencies, allowing larger apertures, shorter
accelerators, lower power consumption and less required infrastructure. Current accelerators
which make use of SCRF technology have operated at relatively low gradients, between 5-10
MV/m. A description of some major facilities which currently make use of low gradient
(between 5-10 MV/m) SCRF technology with applications outside of high energy physics are
described in Appendix A. Over the past decade, advances in laboratory settings have raised the
gradients to over 30 MV/m, offering dramatic new opportunities for research facilities and
industrial applications. However, achieving such high gradients reliably at the scale needed for
the ILC effort will require gaining good control of the niobium cavity surface preparation steps.
These involve complex operations involving highly reactive chemicals and high temperatures,
where the possibility of contaminating the surface is large. The ILC R&D effort will therefore
require a more refined understanding of surface processing steps, new fabrication methods, and,
perhaps, the development of new materials such as large grain niobium. Further, in order to
optimize the performance of the cavities, ILC R&D will also explore improvements and
standardization in SCRF cavity processing, new cavity shapes, and better control of higher order
cavity modes. An essential goal of the effort will involve transfer of SCRF technology to U.S.
industry and the expansion of U.S. and worldwide industrial capabilities in SCRF cavity
production.
The scale of the ILC effort will make it the most important future driver for SCRF acceleration
technology. Thus the ILC R&D will be the engine through which the entire field will be
advanced, and opportunities will be created for the myriad other applications across the physical,
materials, and life sciences.
Efficient, Reliable RF Power Systems
In linacs, the electromagnetic fields present in the cavities through which the particles move and
gain energy are generated in a series of steps. A modulator converts AC power from the power
grid to short pulses of constant high voltage. This pulse is delivered to a klystron in which
electrons are oscillated by permanent magnets, gaining energy in the high voltage and amplifying
the RF electromagnetic wave generated by the oscillating electrons. This wave is then
transported through wave guides to the front end of the cavities, thereby creating the fields which
accelerate the particles in the beam. New modulators and klystrons are needed to generate the
higher power electromagnetic waves needed for future accelerators such as the ILC. Techniques
for improving the efficiency and reliability of these components also need to be developed.
Electron and Positron Beam Sources
One of the important features of the ILC is that the electron beam will be highly polarized. The
development of an electron beam source capable of the > 80% polarization, reliability, stability,
and long bunch trains desired for the ILC will require R&D on time-programmed high power
lasers, photocathodes, and high voltage electron gun technology. The need to produce a high
4
quality positron beam will spur further research on undulators for polarized photons and
Compton back-scattered polarized photon beams.
Damping Rings
The electrons and positrons emerging from their respective sources are converted into high
intensity, small phase space beams in the ILC damping rings. Superconducting wiggler magnets
occupying 200m of the rings give rise to beam cooling through photon radiation. New methods
for suppressing positive ion or electron buildups are required. These damping rings will require
parallel development of lower frequency superconducting RF cavities and cryomodules together
with fast injection and extraction systems and associated pulse compression techniques.
Beam Instrumentation
In order to ensure that a sufficient luminosity is achieved (i.e. so that the rate of collisions
between high energy electrons and positrons is high enough to see rare phenomena), the electron
and positron beams must be focused at the Interaction Point (IP) to a size of about 500 by 5 nm.
However, any particles which stray far from the tight beam core must be collimated, so that they
would not be mistaken for products of a collision. In order to maintain this very stringent set of
constraints, beam parameters such as the energy spectrum and polarization must be very
precisely measured, requiring sophisticated beam diagnostics and instrumentation Such
measurements should be made both before and after interaction. Beams coming in to the
interaction point must be measured to facilitate tuning of the machine. Fast intra-train and slow
inter-train feedbacks are needed to keep the beams in collision and maintain the small beam
sizes. The detector and beamline components must be protected against errant beams. After
collision, the beams must be transported to the beam dumps safely and with acceptable losses.
These requirements require the development of new instruments for beam energy spectroscopy,
non-destructive measurement of beam position, profile and angle such as cavity higher order
mode monitors, laser wire detectors, and X-ray synchrotron radiation cameras capable of
changing real-time beam measurements.
Large Scale Metrology and Alignment
The extraordinary precision and stability in alignment required to deliver a beam with nanometer
precision over kilometer-scale distances will require advanced alignment and control systems.
Robotic survey systems for real-time dynamic micrometer level alignment of ILC components
over kilometer-scale distances will be required. Nanosecond-scale feedback systems based upon
new beam position instrumentation will be needed, which will thereby enable the development of
fast beam correction algorithms required for achieving beam stability. The ILC will use such
systems to provide spatial corrections for large mechanical systems such as magnets and
cryomodules.
Accelerator Simulations
5
Development of new cradle-to-grave simulation codes for study of wake fields and collective
instabilities, effects of magnetic element misalignment and ground motion will be critical to the
design and operation of the ILC.
Scientific and Technological Benefits of ILC Accelerator R&D
Advances in accelerator technology enabled by the large scale ILC R&D effort are likely to have
a direct impact in the near to mid-term on a range of future facilities with applications to a broad
array of fields. Broad, direct impacts on accelerator based facilities include:

Availability of lower cost, higher reliability components. The industrialization effort
associated with the ILC R&D program in SCRF technology promises to make available
high quality, reliable superconducting cavities, cryomodules, and klystrons. The
resulting substantial drop in unit price for these items will likely have far reaching
benefits for a very wide range of future accelerators.

Efficient, reliable RF power systems. Similarly, the high efficiency, reliable RF power
systems being developed for the ILC will lower operational costs and downtime for a
wide range of future facilities.

Advanced beam instrumentation and accelerator simulation tools. Further, the
nanometer scale beam instrumentation along with the new accelerator simulation tools
being developed for the ILC will also find general use for all accelerator facilities.
In more detail, the ILC accelerator R&D effort will likely have a substantial impact on the
following future accelerator facilities with a range of wider applications: 4

Future high current proton linacs for neutron spallation sources (such as a proposed
upgrade of the Spallation Neutron Source (SNS)) will benefit from high-gradient SCRF
cavities, efficient high power RF systems and the industrial and laboratory experience
and infrastructure arising from the ILC R&D effort. The high gradient SCRF linac
system (cavities, cryogenics, and RF power systems) can be applied with little
modification to build shorter, less costly proton linacs (due to reduced cryomodule and
conventional construction costs). Further, SCRF proton linacs with no normal
conducting sections yield better performance with regard to beam halo growth with
attendant beam loss, and the ILC industrialization effort promises to make available high
quality, reliable SCRF linac systems at significantly lower unit prices than would have
been possible otherwise. This opens up the possibility for higher power spallation
sources. 5
Wider Applications: These neutron sources provide intense pulsed neutron beams for
scientific research and industrial development, including applications to materials
science, chemistry and the life sciences.
4
For more details on these and other applications of SCRF, please see the RF Superconductivity - 2004 brochure,
prepared by Hasan Padamse, available at http://www.lns.cornell.edu/~preprint/hasan/BrochureOriginal.pdf.
5
Private communication from P. Montano, Division of Scientific User Facilities, Basic Energy Sciences.
6

New Storage Ring Light Sources will benefit from ILC damping ring research and
innovations aimed at developing high intensity small phase space beams, such as a much
better understanding of collective effects (fast ion instability), creation of very low
emittance beams, impedance control, as well as fast injection and extraction systems and
associated pulse compression techniques.
Wider Applications: These highly sought after light sources have had and are expected to
continue to have an enormous impact on materials and life sciences such as molecular
and electronic structure determination, elemental analysis, imaging, microtomography,
the structure of proteins and cells, chemical reaction dynamics, environmental impacts on
soils and water sources, and X-ray lithography. For example, synchrotron radiation has
been used to aid in the design of drugs – recent studies contributed to the development of
new pharmaceuticals effective in the treatment of AIDS and influenza, and
crystallographers using the Brookhaven and Argonne synchrotrons solved the major
structure of the ribosome, the cell’s factory for assembling proteins.6

Energy Recovery Linacs (ERL) are next generation light sources which will be based
on SCRF technology as well as efficient, reliable RF power systems developed for the
ILC. The SCRF technology is critical to making ERLs viable as they must use low loss
SCRF technology since energy recovery is not efficient in normal conducting structures.
Focused R&D to improve surface properties of SCRF cavities, either through improved
processing techniques or the use of different superconducting materials, will improve
ERL performance. Further, just as with storage ring light sources, the fast injection and
extraction systems and associated pulse compression techniques developed for the ILC
damping rings will find application in ERLs as well. It would also be important in an
upgraded storage ring operating in a hybrid mode (both storage ring and ERL modes).
Note that while ERLs will make use of the advanced SCRF cavities and technologies
being developed by the ILC R&D program, they will run in continuous wave (CW) mode
rather than a pulsed mode as in the ILC, and therefore may not run at the highest possible
gradients due to higher operating costs associated with increased cooling and power
needs.7
Wider Applications: These ERLs will be capable of producing sub-picosecond light
pulses with much higher peak brilliance and coherence than storage right light sources
with comparable average light fluxes. Such pulses will enable atomic resolution, real
time studies of single molecule dynamics and are expected to have an even greater impact
on the material and life sciences than the previous generation of light sources.

The development of Free Electron Lasers (FEL) based on SCRF linacs operating at
frequencies ranging from the IR to the soft X-ray range will benefit from cost and size
reductions enabled by SCRF acceleration and efficient, reliable RF systems. Focused
R&D to improve surface properties of SCRF cavities, either through improved processing
techniques or the use of different superconducting materials, will improve FEL
6
“The Structure of the 50S Ribosomal Subunit at 2.4 Å Resolution and its Functional Consequences,” Poul Nissen,
et al, American Crystallographic Association Golden Anniversary Meeting, (July 2000).
7
Private communication from P. Montano, Division of Scientific User Facilities, Basic Energy Sciences.
7
performance. The present cost of laser energy delivery is on the order of $1/kJ, and it is
expected that the industrialization of cavity production enabled by the ILC R&D effort
and the subsequent production rate required for the ILC may help to bring down this
price below the $0.10/kJ range needed for FELs to become competitive for large-scale
industrial and medical uses.8 The fast kicker technology being developed for the ILC
damping rings is also important to FELs, where the beam is distributed from the linac to
multiple independent FEL beamlines. Note that like ERLs, FELs will also run in
continuous wave (CW) mode rather than a pulsed mode.
Wider Applications: FELs will have a large range of applications reaching from
industrial processes such as laser peening to toughen ship propellers to medical
applications such as laser surgery to ultra-fast phenomena in condensed matter, atomic
physics, chemistry and life sciences. FELs are also very promising as the underlying
technology for the next generation of high power laser weapons systems for naval
defense.

Powerful, electron accelerator based terahertz radiation sources are currently being
developed using SCRF technology very similar to that used for FELs and ERLs. The
ILC R&D efforts regarding the industrialization of high quality SCRF cavities and
accelerator systems as well as the development of efficient, reliable RF power systems
will play a key role in enabling wider scientific and industrial development of terahertz
radiation sources.
Wider Applications: Terahertz radiation is a largely unexplored band of frequencies with
potential applications ranging from imaging for defense and homeland security
(explosives detection, mine detection, security technologies), medical imaging,
manufacturing, pharmaceuticals, to fundamental materials science, biology, optics, and
chemistry.

Revolutionary X-Ray Free Electron Lasers, such as the European X-Ray Laser Project
(XFEL) to be built in Germany starting later this year, will use high gradient SCRF
cavities and efficient high power RF systems based upon ILC prototype work to create
brilliant (a billion times as bright as current light sources), coherent pulses of X-rays
capable of observing atomic scale processes in materials with femtosecond time
resolution. These facilities have been directly by advances in SCRF technology
associated with the ILC R&D effort.
Wider Applications: X-Ray FELs promise to have not only a substantial impact in
materials science but also on the biological sciences – for instance, allowing structural
biologists to resolve protein structures that are difficult to crystallize.

Next generation, large scale medical accelerators for proton and neutron therapy may
benefit from the use of high gradient SCRF technology as well as efficient high power
“Jefferson Lab Free Electron Laser Program Overview,” presentation by Fred Dylla for the Jefferson Lab FEL
Team, FEL Users/Laser Processing Consortium Meeting, March 8, 2006, and private communication with G.
Williams at Jefferson Labs.
8
8
RF systems. The current state-of-the-art linac for neutron therapy of prostate and other
tumor treatment uses a roughly 100 foot long proton linear accelerator to generate the
high current neutron beam. With the accelerating gradients as required for the ILC, a
linac of about 25 feet would be required, possibly bringing this technique into the range
affordable to major research hospital centers.
Wider Applications: Proton and neutron therapy allows the irradiation of tumors with
greater specificity, precision, and intensity than other methods of radiation therapy,
giving rise to less normal tissue damage. Almost 40,000 patients have been treated with
proton therapy as of July 2004.9

Advances in efficient, reliable RF power systems (modulators, klystrons) due to the ILC
effort may also have an impact on the production of more efficient photon based
medical accelerators which are widely used for radiation therapy today.
Wider Applications: About 10,000 cancer patients are treated every day in the United
States with photon or electron beams from electron accelerators.10

SCRF technology is also starting to be used to build new linear proton and deuteron
accelerators for the production of radio-nuclides for medical diagnostics and
therapy such as the SARAF project in Israel. This technology may help enable practical
hospital-based facilities capable of both particle therapy and radioisotope production for
procedures such as PET scans.11
Wider Applications: Radio-nuclides are used in medical diagnostic tests that primarily
show the physiological function of the system being investigated, and are an important
complement to anatomical images provided by CT or MRI. In U.S. hospitals, one of
every three patients benefits from diagnostic or therapeutic nuclear medicine procedures
(about 36,000 per day). More than 50 diagnostic tests involve nuclear medicine and 20%
of all radiopharmaceuticals use isotopes produced in accelerators.12

Spallation neutrons from proton drivers may be used for accelerator based
transmutation of radioactive waste, to transmute long-lived actinide isotopes and
fission products to stable or quickly decaying isotopes. SCRF linacs would substantially
lower the power needed for operation of such facilities, and the larger bore radius of
SCRF cavities will relax alignment and steering tolerances as well as reduce beam loss.
J. Sisterson, “Ion beam therapy in 2004”, Nuclear Instruments and Methods in Physics Research, B241, p.713
(2005).
10
. Projected from a 1994 survey: J. B. Owen, et al, “The Structure of Radiation Oncology in the United States in
1994,” Int. J. Radiation Oncology Biol. Phys. 39:179 (1994).
9
11
See for example, A. J. Lennox, “Hospital-based proton linear accelerator for particle therapy and radioisotope
production,” Nuclear Instruments and Methods in Physics Research, B56/57, pp. 1197-1200 (1991).
HEPAP’s Composite Subpanel for the Assessment of the Status of Accelerator Physics and Technology, (May
1996), J. Marx et al.
12
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Wider Applications: The increasing demand for nuclear energy will be accompanied by a
substantial growth in radioactive waste products with life-times in the 10,000 year range.
Transmutation of these waste products to stable isotopes or those with 100 year lifetimes
can lessen some of the technical problems associated with storing long-lived, high level
radioactive waste.

The nanometer scale beam instrumentation may be of interest to accelerators used in ion
implantation with applications to the fabrication of novel nano-scale devices.
Wider Applications: Ion implantation is essential to the multi-billion-dollar
semiconductor industry, using ion beams from accelerators to embed doped layers in
semiconductors. Ion implantation is also used to alloy a thin surface layer and harden
surfaces such as those of artificial hip or knee joints, high-speed bearings, or cutting
tools.

Future Rare Isotope Accelerators (RIA) will be based upon novel low and medium
velocity SCRF accelerator technology as well as new, efficient high power RF systems
whose development will benefit from laboratory infrastructure and industrial
development spurred by the ILC R&D effort. These accelerators promise to provide deep
insights into nuclear astrophysics such as the origin of the heavy elements.
Wider Applications: RIAs are expected to have applications to radioisotope production
and biomedical research, the nuclear physics needs for science-based nuclear stockpile
stewardship, R&D for accelerator based transmutation of radioactive waste, as well as
materials science.

New, high energy, continuous proton beam facilities for high precision nuclear
physics experiments will make use of higher-gradient SCRF cavities as well as new,
efficient high power RF systems. These facilities will help map the details quark and
gluon structure of nucleons. For instance, DOE has identified upgrading the energy of the
Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Labs as a nearterm priority. This upgrade requires higher gradient SCRF cavities, and the simultaneous
involvement of Jefferson Labs in the ILC SCRF effort will accelerate both efforts.

Next-generation heavy ion colliders for nuclear physics applications such as two
proposed upgrades of the Relativistic Heavy Ion Collider, RHIC II and eRHIC, will
both likely make use of SCRF cavities as well as new, efficient high power RF systems in
order to probe high energy density nuclear physics as well as the partonic spin and flavor
structure of nucleons. Such upgrades will benefit from the infrastructure development
undertaken by the ILC R&D program.

SCRF technology will likely be critical to efforts to extend the frontiers of high energy
physics as integral elements of the technology needed to build a muon collider. A 3 TeV
muon collider may likely fit in a site like Fermilab. However, as muons are unstable,
their decays produce a heat load, large detector backgrounds, and dangerous levels of
neutrino radiation, making the realization of a muon collider very challenging. However,
10
the last problem can be turned into a feature, as muon storage rings may be ideal
neutrino factories.
Further, the accelerator ILC R&D program may also have a range of indirect benefits that extend
beyond the direct applications of accelerators such as:

ILC R&D can be expected to advance understanding of RF superconductivity and
material science. Processing ultrapure niobium cavities on a large scale should advance
the metallurgy of refractory metals generally.

Improvements in vibration damping and ground motion correction as well as extremely
stable low mass mechanical support systems for experimental detectors can be used in
other scientific applications.

The ILC R&D devoted to novel polarized electron source may help develop new
technology for electron beam sources more generally, with potential future applications
to novel electron microscopes, such as a Spin-Polarized Low Energy Electron
Microscope (SPLEEM).13

The development of undulators for polarized photons and Compton back-scattered
polarized photon beams done as part of the positron source R&D effort may be of interest
as an alternative source of photons for photon radiotherapy.

Advanced techniques for simulating electromagnetic structures used for accelerator
modeling and simulation are of general benefit.
International Context of ILC Accelerator R&D
At present, U.S. industry lags behind that in Europe and Japan in attaining key competencies in
high gradient SCRF technology. The main activity in developing high gradient SCRF was in the
DESY laboratory in Germany over the past decade. Most of what is known about the processes
necessary to polish niobium surfaces, fabricate clean multi-cell units and assemble them into
cryomodules, and provide the RF power sources was achieved in test facilities in DESY. The
only high gradient cavities in operation as an accelerator are at DESY. Most importantly, the
Germans have succeeded in transferring the main steps in fabrication to their industry. The total
investment in high gradient superconducting RF at DESY where the technology was pioneered
exceeded $150M (European accounting without manpower) over several years. There is a
proposal to build a new European superconducting test facility on the $100M scale.
The Japanese have started superconducting RF programs more recently, capitalizing with their
characteristically close interaction with Japanese industry. Their focus so far has been on
developing new shapes for cavities which offer even higher acceleration, and their single cell
cavities have reached gradients above 50 MV/m. Their pioneering work on electropolishing to
get the final surface smoothness required has been taken over by labs elsewhere. The KEK
13
For recent work along these lines, see M. Kuwahara, et al.: Jpn. J. Appl. Phys. Vol. 45, No. 8A (2006) pp. 62456249, or slides of a talk given at Jefferson Labs, http://casa.jlab.org/seminars/2006/slides/kuwahara_061114.pdf.
11
laboratory in Japan is already embarked on building a test facility similar in scope to that
proposed by a US consortium at Fermilab.
Some developing industrial nations have seen the promise of superconducting RF for their own
research and commercial applications. In particular, Korea and India are now stepping up their
investment in superconducting RF activities with an eye toward developing domestic light
sources, neutron facilities or heavy ion programs.
For major high energy physics projects such as the ILC or high intensity neutrino sources, we
expect a very high degree of international collaboration. The scale of the ILC will very likely
demand that accelerating cavities be produced in the US, Europe and Asia, using local industry.
The head start that Europe, and to some extent Japan, have makes it imperative that the US make
a vigorous start in developing its own superconducting RF technology.
In the U.S., a new consortium of laboratories has developed plans to advance the state of the art
in superconducting acceleration, and to transfer the technologies to industry. This consortium is
driven primarily by the ILC needs, but has important elements that were brought by the nuclear
physics and basic energy sciences communities. Fermilab serves as the leader of the consortium
to develop the superconducting cavities, with Argonne, Thomas Jefferson Laboratories and
Cornell University as key players. The proposed R&D program is distributed among these
laboratories under Fermilab leadership. A separate consortium lead by SLAC, with help from
Lawrence Livermore National Laboratories, is developing the new power sources – new
modulators, klystrons and RF delivery systems. These programs have been seeded primarily
through laboratory generic accelerator R&D funds, but would benefit greatly from dedicated
large scale support from the ILC R&D effort. This effort will consist of two major elements –
the support needed to have industry build a series of cavities, cryomodules, power couplers,
modulators, klystrons, and the provision of test facilities at DOE laboratories that can measure
the performance and diagnose possible problems of these components. The industrial production
will require a learning curve, with first prototypes expected to fall short of desired ultimate
specification. Close collaboration of industry and laboratories in this learning phase will be
essential, with rapid turn-around from production of items, test in laboratories, development of
plans for improvement and subsequent industry production of the next series of prototypes.
The extensive existing infrastructure and capabilities of the U.S. national laboratory system
across the many scientific disciplines with substantial interests in SCRF technology can
provide the Nation with a competitive advantage in pursuing SCRF technology, if these
resources are quickly mobilized on a large enough scale. The expansion of accelerator
science, technology, and industrialization envisioned for the ILC R&D program, provides the
opportunity for the U.S. to become a world leader in high gradient SCRF technology. This
leadership role would be critical in accelerating the wide-scale adoption of SCRF in cutting edge
facilities with benefits to the myriad of applications described above. Such a course of action
will in turn help enable continuing and future U.S. leadership in disciplines ranging from
materials science to radiation therapy.
B. Detector R&D
12
Exploring with precision the physics of the Terascale at the ILC poses tremendous challenges to
current detector technology. Most ILC detector subsystems will have to perform beyond the
current state-of-the-art. A comparison of the ILC detector requirements with the performance of
the detectors recently built for the Large Hadron Collider (LHC) can provide a sense of the
challenge.
For example, at the heart of an ILC detector system will be a vertex detector, a compact particle
tracking device about the size of a wine bottle which surrounds the interaction region. The
vertex detector is analogous to a 3D digital camera – it consists of concentric cylinders of finely
segmented silicon detectors, similar to the arrays of small sensors used to record pixels in digital
cameras. However, for the ILC, a billion pixels are needed in this 3D camera to measure the
tracks of outgoing particles with micron precision. In particular, this kind of precision is critical
in order to accurately detect and characterize exotic heavy quarks produced by the collisions at
the ILC which are critical pointers to new physics. These heavy quarks live only for a billionth
of a second and decay at “vertices” within the detector to familiar forms of matter. In order to
achieve this precision, the sensor size for an ILC vertex detector must be reduced by a factor of
30 and the sensors must be thinner by a factor of 20 (to avoid disturbing the particles) as
compared to those used at LHC detectors. Further, as we describe in detail below, the readout
speed required for the ILC is also much greater than the present state-of-the-art can provide –
that is, we must be able to take consecutive 3D gigapixel pictures of the particle tracks much
faster than any digital camera can today.
Meeting these demands is plausible only because the environment at the ILC is benign by LHC
standards. The LHC demands detectors that are extremely radiation hard and that can operate at
high speeds. The ILC, on the contrary, relaxes the radiation hardness requirement, admitting
many additional technologies. It runs at comparatively low rates and consequently poses lighter
demands for power dissipation. High precision, thin detectors are needed, which have not been
developed for LHC.
Vertex Detector
The vertex detector is challenging because of the need to combine high precision with speed.
The electron and positron beams at the ILC consist of trains of electrons and positrons which
cross about five times a second. Each of these trains, in turn, consist of about 3000 bunches of
more than 1010 electrons each, spaced by about 300 ns. Thus, 1010 electrons and positrons cross
within the detector (a bunch crossing) every 300ns for a period of 0.9 microseconds, five times a
second. Now, each of these bunch crossings will result in the deposition of roughly 5 particles
per square centimeter in the innermost layer of the vertex detector. If the signals are read out
only once for the entire train of 3000 bunches-crossings, the accumulated backgrounds
overwhelm the signal, and render the device useless. Unfortunately, the state-of-the-art in the
technology that was the basis of the precise SLD detector used in the linear collider at SLAC,
Charge Coupled Devices (CCDs, also familiar as the core technologies in digital cameras and
camcorders), permits no more than one readout per train.
A British group has developed a new system based on CCDs, but while it is several orders of
magnitude faster than any previous CCD system for science, it is probably still too sluggish, and
13
the devices may not hold up in the radiation environment of the ILC. Other groups are pursuing
a variety of other approaches. Some are attempting to adapt the LHC devices, with their higher
readout speeds, to the ILC environment by making them thinner and more finely grained. Others
are developing smart devices with streamlined readout, or with the ability to timestamp the
signals locally. One of these strategies will need to work if the detector is to meet ILC needs.
Electromagnetic Calorimeter
The electromagnetic calorimeter (ECAL) is designed to measure the energy of light, high energy
particles emerging from the interaction region that interact primarily via electromagnetic
interactions, such as electrons or photons. The ECAL is a “sandwich calorimeter” consisting of
finely segmented, alternating layers of an absorber material with high electric charge nuclei (like
tungsten or lead) and a sensor and readout material. A high energy electron entering a tungsten
absorber layer of sufficient thickness will likely be deflected by the high electric field near some
nucleus strongly enough so that it will emit a virtual photon with enough energy and momentum
to decay into an electron positron pair, roughly moving in the same direction as the original
electron. Thus, one high energy particle becomes three, which in turn further interact with other
tungsten nuclei, creating a cascade or shower of particles. This shower will then enter a sensor
plane, which may be made of silicon pad diodes, monolithic active pixel sensors (MAPS) or of
scintillator strips or tiles. In this last case, as the shower passes through the scintillators, each
particle creates a further shower of photons which can then be readout by novel solid-state,
silicon based photo-sensors or silicon photomultipliers. The energy contained in the initial high
energy electron can be computed by measuring the depth and size of the resulting showers of
light through the many layers of the ECAL.
The need for exquisite energy resolution for precision tests of the physics of the Terascale will
require substantial improvements over current ECAL technology. The sensor sizes in the
electromagnetic calorimeter need to be a factor of 200 smaller than those in the LHC. Currently,
the CALICE collaboration, with 190 physicists and engineers drawn from 32 institutes and 9
countries drawn from Europe, Asia and the Americas, is studying the fine-grained silicontungsten device that might make this possible. A group from SLAC, Oregon and Brookhaven
and another from Asia are testing devices based on the same principle, but with somewhat
different electronics and mechanical design. Further, though silicon-based photo-sensors have
been developed by various groups, the signal-to-noise ratio, gain, long-term performance, and
pixel density required for the ILC calorimeter has not yet been achieved. It is expected that the
ILC R&D effort will be a significant driver for this new technology.
Hadronic Calorimeter
The Hadronic Calorimeter (HCAL) is responsible for measuring the energy of the heavier
hadrons (that is, particles which experience nuclear as well as possibly electromagnetic
interactions) that may deposit only some of their energy in the ECAL. Several technologies of
fine-segmented sampling calorimeters (i.e. with separate absorber and sensor layers just like the
ECAL above) are under investigation with either analog or digital readout.
The analog readout hadronic calorimeters use scintillator tiles as sensors, and steel or lead as
14
absorbers. These scintillator tiles would be readout by the silicon photo-detectors discussed
above.
The digital readout calorimeters make use of gaseous signal amplification, such as GEMs
(Gaseous Electron Multipliers), Micromegas (Micro mesh gaseous structures) or RPCs
(Resistive Plate Chambers) which are being developed in-house specifically for this applications.
These calorimeters consist of thin and large area gas-filled chambers interspersed between steel
absorber plates. The hadronic showers generated in the steel absorber plates create ionized
electrons in the gas-filled chambers as they pass through. These are then accelerated and
detected digitally at the chamber anode, which is segmented in small pads of about 1 cm2 size,
matching the granularity needed for the particle flow algorithms used to compute jet energies to
the precision required.
The Detector Magnet
Fundamental to determining the momentum of charged particles is the fact that their trajectories
bend in the presence of a magnetic field. Thus, a basic component of any ILC detector will be a
large superconducting electromagnet providing such a magnetic field. The precision in
momentum needed for an ILC detector requires a very strong magnetic field, nearly 50,000 times
the strength of the magnetic field at the Earth’s surface, which is also highly uniform over a large
volume.
Data Acquisition, Management, and Analysis
While the overall rate of bunch crossings at the ILC will be on the order of 104 per second or 10
kHz, the pulsed nature of the ILC beam will result in much higher peak rates of several MHz.
Appropriately tailored strategies for the acquisition and management for the large amount of
vertex and calorimeter data associated with such a data stream need to be developed and
validated. Further, novel data analysis and sharing tools will be needed on a global scale to
extract the relevant physics from the data emerging from the ILC.
Broader Impacts of ILC Detector R&D
ILC detector R&D will have important payoffs for instrumentation and data analysis in many
other fields ranging from medicine to astrophysics. 14

A new method for photon detection that is suitable for whole-body PET scans. The
ILC calorimeters may require a huge number of photon detectors. One candidate device
is a silicon photomultiplier, in which a photon triggers an avalanche in silicon. The
silicon photomultiplier is small and inexpensive, and thus very suitable as a readout
sensor both for the calorimeter and whole-body PET scans, but current test chips are too
noisy. ILC physicists are working to improve their quality.
Many of the detector applications outlined below were discussed in “Detector R&D for the International Linear
Collider”, prepared for the EPP2010 Committee by the World-wide Study for the Physics and Detectors for the ILC,
(provided courtesy J. Brau).
14
15

Medical imaging may also benefit from the development of CMOS devices for the ILC
vertex detectors.

Future experiments in particle physics, astrophysics and nuclear physics will also
benefit from ILC detector R&D. Even those with very different goals are likely to draw
upon technological advances driven by ILC detector needs, just as some candidate ILC
devices draw upon advances made in connection with LHC detector R&D. In the case of
the ILC, R&D on a fast, finely-segmented vertex detector and new calorimetry are likely
to benefit other experiments, as are technologies associated with the high resolution
tracking devices, the large, high-field, highly uniform magnet, and the detector
stabilization, alignment, and monitoring systems.

Particle detector instrumentation. The very finely pixelated track detectors developed
for ILC experiments will find applications such as security scanning and medical
imaging. New large scale detector technologies that will be stimulated by ILC include
very thin silicon pixel detectors, GEMs and micromegas.

Computing and computer science. The very large data sets collected in ILC
experiments and the need for access to users distributed around the world will stimulate
further development of GRID computing techniques. Recognition of complex topology
collision events will stimulate artificial learning algorithm development.
International Context of ILC Detector R&D
Any detector is an assembly of individual devices. As in the case of the LHC detectors,
institutes in different countries will take responsibility for the construction of individual
components and come together to assemble the full detector. After running starts, the
international collaboration of physicists will work together to analyze the ILC data. The US
must play its part in the development of the experimental apparatus if it wants to be a leader in
the physics of the ILC.
The World-Wide Study (WWS) is coordinating the R&D for the ILC detectors with the
recognition of the ILC Steering Committee (ILCSC) and Global Development Effort (GDE). It
is fostering the development of concepts for the overall detector design, and has set up a
timetable for completing baseline designs with cost estimates. It has also set up an R&D panel to
monitor and prioritize the various detector research areas. This framework ensures that US ILC
detector research is focused and effective.
Once the technology is understood, it is a major undertaking to develop a real (and economical)
design for a large-scale device. For example, the silicon-tungsten technology envisioned for the
ILC electromagnetic calorimeter is similar to the technology used for luminosity monitors at
other electron-positron accelerator facilities such as SLAC and LEP, but designs that contain cost
and power consumption and respect mechanical constraints are needed to turn it into an ILC
detector. Current US funding of detector R&D has been limited - by contrast, the European
Union has recently committed more than 7 million euro over the next three years to develop and
beam test new detector technologies for the ILC, and individual European nations and
laboratories are supporting detector R&D efforts at a similar level. Investment in detector R&D
16
at this early stage will allow US physicists to contribute to inventing the ILC detector
technologies and to the development of the overall detector designs. Ultimately, it will allow US
physicists to be full partners in the ILC detectors and the exploration of the physics of the ILC.
III. Broader Societal Benefits of ILC R&D
While the future direct and indirect technological benefits of frontier research in accelerator and
detector science and technology can be assessed with some confidence, there are a range of
broad societal benefits of basic research that are not captured by such an analysis but may be
equally important in assessing the overall utility of the program. These broader societal benefits
can be grouped into three general categories: knowledge benefits, workforce development
benefits, and benefits associated with international scientific collaboration.15
Knowledge Benefits
Much of basic research is driven by curiosity, a thirst for knowledge and understanding. Perhaps
the most direct benefits from such research are the broad societal impacts associated with the
creation and flow of new knowledge. In the case of the ILC R&D program, the knowledge
generated is expected to largely take the form of scientific and technical knowledge relevant to
accelerator and detector physics and technology. As was discussed in the previous section, this
knowledge has substantial value as a result of its potential application to a range of other
scientific and technological problems of substantial interest to a range of scientists and engineers.
The resulting transfers and flows of this knowledge at universities, workshops, summer schools,
and to industry will not just impact the applications described in the previous section, but also
play an important role in the dissemination and advancement of the state of knowledge in a range
of related fields. That is, a substantial investment in ILC R&D will strengthen a wider
knowledge network linked to accelerator and detector science and technology. The reach of this
network – ranging from nuclear medicine to national security – highlights the range of the
resulting knowledge benefits. In the next section, emerging tools and techniques to measure
such benefits will be discussed.
Workforce Development Benefits
Another fairly immediate societal benefit of basic research is its important role in the nation’s
capacity to attract, train, and retain talent. These benefits, again, extend beyond any particular
technological application and are difficult to capture with a direct market value – they are instead
associated with the broad added value of talented human capital.
In the case of the ILC R&D program, the major workforce issue surrounds the health of the high
energy physics and accelerator communities in the U.S. as the center of gravity of these fields
shift to Europe with the operation of the LHC. By the end of this decade, there will be no high
energy physics accelerator facility in operation within the U.S., posing a substantial challenge to
the capacity of this community to attract, train and retain talent. The ILC R&D program will
The following discussion arose from conversations with B. Valdez (DOE/SC) – see also U. Amaldi, “Spin-offs of
High Energy Physics to Society” at the International Europhysics Conference-High Energy Physics ’99, and the
discussion “What is the use of basic science?” by C. H. Llewellyn Smith found at:
http://press.web.cern.ch/Public/Content/Chapters/AboutCERN/WhatIsCERN/BasicScience/BasicScience1/BasicSci
ence1-en.html
15
17
help retain and expand U.S. talent and workforce capacity in this area, sowing the seeds for
regaining a leadership position in this area.
While some of these talented individuals will primarily contribute directly to closely related
areas of basic research, a substantial fraction will instead contribute to a range of other
endeavors, where their fundamental training (and, perhaps, the new techniques and approaches
they bring with them) will be utilized.16 The value of the corresponding dissemination and
diffusion of knowledge and talent over long periods of time may well be substantial. For
instance, studies of recent physics Ph.D. recipients have shown that at least a third move on to
other research areas and/or the private sector, and further, a majority of those individuals find
that their fundamental physical understanding and problem solving skills (though not their
specific training) are well utilized in these new capacities.17 In high energy and accelerator
physics, specific numbers available through HEPfolk, a community census program at LBL. 18
Preliminary results show that of 333 graduating HEP students in 2007 from physics graduate
programs, at least 102 plan to start jobs in industry or non-HEP academic institution. As will be
discussed in the following section, further study of this issue is needed to better elucidate the
wider impact of these talented individuals.
International Scientific Collaboration Benefits
Basic scientific discovery and discourse is increasingly international in its scope, with some
indirect but important implications for international diplomacy, development, and
competitiveness. Such discourse has occasionally played an important historical role, such as
communication back-channels during the cold war enabled by scientists (particularly high energy
and nuclear physicists), and the role played by scientists such as Andrei Sakharov in promoting
values which are critical to the scientific process, such as freedom of expression and thought.
International scientific collaborations also provide important opportunities for the transfer of
knowledge, expertise, and talented human capital to and from the developing world, with
important implications for development and national security.
Further, as the scale of basic science research grows, international coordination and collaboration
may be essential for further progress in areas in which no individual nation or group of nations is
willing or able to provide the resources to proceed. U.S. participation in such endeavors,
exemplified by projects such as ITER and the ILC, may become critical for future progress in a
range of scientific areas of substantial importance to national interests and competitiveness. The
establishment of international frameworks for cooperation and coordination as well as the
experience gained by scientists, students, and administrators in collaborations such as the ILC
R&D effort will substantially aid U.S. scientists as they vie for leadership in the global scientific
marketplace.
IV. Towards a Quantitative Analysis of ILC R&D Benefits
As described in a 2001 report by the National Academies, Physics in a New Era: An Overview, “In both the public
and private sectors, it is important that decisions about the development and deployment of a technology be made by
people who understand not only its power but also its limitations… basic physical principles lie at the heart of this
understanding…” p. 161.
17
AIP Pub No. R-282.26 Initial Employment Report: Physics and Astronomy Degree Recipients of 2003 & 2004
18
HEPfolk’s website is: http://hepfolk.lbl.gov/census/index.html, and the data described above was taken from
“HEP Demographics Survey (HEPfolk) report on 2007 Census,” prepared by W. Carithers.
16
18
In order to provide decision makers with tools to better assess the utility of the ILC program and
compare it with other basic science alternatives, it is useful to explore quantitative methods of
accounting for the range of benefits and risks described in the preceding sections. While there
are no tools, models, or methods which can come close to providing a framework for
comprehensive assessment of the benefits of basic science like the ILC R&D program, some
tools are being developed which can capture some aspects of the benefits outlined above and
facilitate comparison of such benefits between different research options.
Tools to Assess Direct Technical and Economic Benefits and Risks
The direct technical risks and benefits of the ILC R&D program – that is, assessment of the
direct impact of the R&D on various accelerator and detector-related technology pathways and
industries – can be measured using survey and performance analysis tools which are not very
different from those being developed and used for technical forecasting and performance
assessment across government and industry today. For example, survey and modeling tools are
being developed at DOE19 to assess the potential future impacts of particular energy technology
programs – such as thin film solar photovoltaics – on both technology performance goals as well
as the economic prospects of the relevant industries. Such tools could be adapted and used to
assess potential impacts of various R&D programs on accelerator and accelerator application
performance measures as well as the economic impacts on the relevant industries (i.e. medical
accelerator, isotope production, etc.) and scientific facility (FELs, ERLs, etc.) capital costs.
These tools can be useful in presenting decision makers with aggregated expert opinion
regarding the impacts of various R&D options on relevant scientific and economic goals. Of
course, the use of these tools will require a substantial effort devoted to the sampling of expert
opinion via workshops, surveys, etc.
Tools to Assess Wider Societal Benefits
The assessment of knowledge benefits through bibliometric methods such as citation and patent
analysis has been substantially advanced over the last decade through the use of increased
computational power and network and cluster analysis. Such analyses can now simultaneously
make use of a wide range of data sets and track scientific and technological connections (such as
citation chains, co-authorship, and patent dependencies) across very long time frames. Further,
they are able to assess important features of scientific networks such as the level and impact of
international and cross-disciplinary collaborations, thereby providing insights into their function,
dynamics, and efficacy.20 Such analyses, if applied to the high energy physics and accelerator
communities enabled and supported by ILC R&D, could provide important insights into the
knowledge, international collaboration, and workforce development benefits of the R&D
program that may flow through these communities. These analyses can be undertaken by groups
in both universities and the private sector, but will require dedicated support. Data available
through HEPfolk should provide a promising starting point for such activities.
19
This discussion is based on conversations with B. Valdez and S. Baldwin at DOE who have been engaged in these
activities for the Office of Science and Office of Energy Efficiency respectively.
20
See, for example, C. S. Wagner, L. Leydesdorff, “Mapping the network of global science: comparing international
co-authorships from 1990 to 2000,” International Journal of Technology and Globalisation 2005 - Vol. 1, No.2 pp.
185 – 208.
19
In summary, some tools are available which may help provide more detailed, integrated
assessments of the benefits of the ILC R&D program. The use of these tools will require some
effort and resources, but may provide decision makers, industry, and the scientific community a
much clearer picture of the impact of the ILC R&D program, and even perhaps suggest areas of
opportunity for enhancing cross-disciplinary collaboration and societal benefits.
Appendix A. Existing Facilities Utilizing SCRF Technology

The Argonne Tandem Linear Accelerator System (ATLAS) was the first accelerator
to utilize SCRF technology to produce precision beams of heavy ions for detailed studies
of nuclear structure.

The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Labs uses
SCRF cavities to provide high energy, continuous beams of protons for high precision
nuclear physics experiments such as mapping the details quark and gluon structure of
nucleons.

The Spallation Neutron Source (SNS), an accelerator-based neutron source in Oak
Ridge, Tennessee, employs a lower accelerating gradient system using SCRF cavities.
SNS provides intense pulsed neutron beams for scientific research and industrial
development, including applications to materials science, chemistry and the life sciences.

The Jefferson Lab Free Electron Laser is a high average power free electron laser
making use of SCRF acceleration and energy recovery to reach average powers in excess
of 10kW at frequencies ranging from the IR to the UV. This laser was developed to
process plastics, synthetic fibers, advanced materials, and metals as well as components
for electronics, MEMS, and nanotechnology, and can by used to analyze ultra-fast
phenomena in condensed matter, atomic physics, chemistry and life sciences.

The Cornell High Energy Synchrotron Source (CHESS), an X-ray storage ring light
source based on the Cornell Energy Storage Ring (CESR) has seen its synchrotron
radiation flux more than doubled as a result of the upgrade of CESR to SCRF technology.
These light sources have an enormous impact on materials and biological sciences.
20