**Office of Fusion Energy Sciences Strategic Plan**

**September 30, 2005**

**Bringing the Power of the Stars to Earth**

**Introduction**

Total world energy consumption has increased by more than 50% during the
past 25 years, making research on new sources of energy a national
imperative. The development of an economical source of fusion power
would greatly reduce current national concerns over imported oil, rising
gasoline prices, smokestack pollution, and other problems associated
with our dependence on a diminishing supply of oil and other fossil
fuels. Fusion power plants would produce abundant energy without
greenhouse gas emissions, while creating manageable waste and little
risk to public health and safety.

Through a combination of sophisticated experiments, high-resolution
diagnostic measurements, comprehensive theory, and computations, today's
fusion researchers are making rapid progress in understanding the
complex, nonlinear processes within hot plasmas. The knowledge base is
now in hand to build an experiment that can produce, control, and
sustain a burning plasma---a plasma whose high temperature is maintained
by the alpha particles produced by fusion reactions in the plasma. The
important scientific challenges of current fusion research are captured
by the following three overarching themes.

-   **Understand matter in the high-temperature plasma state**: matter
    in the plasma state comprises the core of fusion systems and nearly
    the entire visible universe. Understanding the collective dynamics
    of non-equilibrium gasses of charged particles is essential to the
    development of optimum fusion power systems.

-   **Create a star on earth**: the worldwide fusion community is about
    to embark on the construction of ITER (see Figure 1), the first
    magnetic confinement burning plasma experiment. Similarly the United
    States is building the National Ignition Facility, the first
    inertial confinement experiment capable of reaching burning plasma
    conditions. Both experiments will play a major role in establishing
    the foundations of fusion energy by investigating the new physics of
    burning plasmas.

-   **Develop the science and technology to realize fusion energy**: in
    a fusion power plant, the high-pressure, high-temperature plasma
    must be confined in a way that permits efficient, continuous
    operation. This requires steady-state heating, fueling, power
    handling, and control systems for magnetic fusion systems and
    repetitive formation and efficient compression of high-density
    matter for inertial fusion systems.

These overarching themes motivate fifteen scientific questions that
capture the critical physics and engineering issues to be addressed
during the next decade.

1.  *How does magnetic field structure impact fusion plasma
    confinement?*

2.  *What limits the maximum pressure that can be achieved in laboratory
    plasmas?*

3.  *How can external control and plasma self-organization be used to
    improve fusion performance?*

4.  *How does turbulence cause heat, particles, and momentum to escape
    from plasmas?*

5.  *How are electromagnetic fields and mass flows generated in
    plasmas?*

6.  *How do magnetic fields in plasmas reconnect and dissipate their
    energy?*

7.  *How can high energy density plasmas be assembled and ignited in the
    laboratory?*

8.  *How do hydrodynamic instabilities affect implosions to high energy
    density?*

9.  *How can heavy ion beams be compressed to the high intensities
    required to create high energy density matter and fusion
    conditions?*

10. *How can a 100-million-degree-C burning plasma be interfaced to its
    room temperature surroundings?*

11. *How do electromagnetic waves interact with plasma?*

12. *How do high-energy particles interact with plasma?*

13. *How does the challenging fusion environment affect plasma chamber
    systems?*

14. *What are the operating limits for materials in the harsh fusion
    environment?*

15. *How can systems be engineered to heat, fuel, pump, and confine
    steady-state or repetitively-pulsed burning plasma?*

As an integral part of this Strategic Plan, we have identified four
future facilities to realize our Fusion Energy Sciences vision and to
meet the scientific challenges described in the following pages. The
first of these facilities is ITER, which is the next critical step on
the path toward demonstrating the scientific and technological
feasibility of fusion energy. It will be the first fusion science
experiment capable of producing self-sustaining fusion reactions or a
"burning plasma." Construction of ITER, which is an international
collaboration with the
![](media/image1.jpeg){width="3.244488188976378in"
height="3.25in"}European Union, Japan, Russia, China, and South Korea,
is scheduled to begin in 2006 in Cadarache, France. The other three
future facilities are the Next Step Spherical Torus, which is an
experiment to study confinement, stability, and sustainment of a
spherical torus plasma at fusion-level conditions, the Integrated Beam
Experiment (IBX), which is an experiment to demonstrate the feasibility
of using heavy ions as the driver for a practical inertial fusion energy
system, and one or two yet- to-be determined facilities to develop and
test power plant components and materials needed to make fusion a viable
commercial energy resource. In addition to these facilities, other
national programs will have their own set of future facilities, many of
which will help to answer the fifteen scientific questions listed above.

**Our Strategies**

Given the substantial scientific and technological uncertainties that we
know exist, we will employ a portfolio strategy that explores the
science of a variety of magnetic and inertial confinement approaches. We
are confident that this strategy will ultimately lead to the most
promising concept for fusion applications. The research projects in this
portfolio will be carried out by individual investigators, small
research groups, and large research teams, as appropriate, using peer
review as the primary method for evaluating proposals, assessing
progress and quality of work, and for initiating or terminating
facilities, research projects, and construction projects. Advanced
computational modeling will be a central feature or our program for
guiding and designing future experiments, testing the agreement between
theory and experiment, and exploring innovative designs for fusion power
plants. Accordingly, a major effort to advance the state-of-the-art in
simulation of plasma behavior in partnership with the Office of Advanced
Scientific Computing Research is an important element of our plan.

To ensure the highest possible scientific return on limited resources,
we will extensively engage with and leverage other DOE programs and the
investments of other agencies in such areas as materials science, ion
beam physics, and laser physics. Large-scale experimental facilities
will be necessary to test approaches for self-heated (burning) fusion
plasmas, for inertial fusion experiments, and for testing materials and
components under extreme conditions. Where appropriate, the rewards,
risks, and costs of major facilities will be shared through
international collaborations.

The fifteen scientific questions listed in the previous section can be
arranged into six groups. We will organize the overall Fusion Energy
Sciences effort around six "campaigns" to address the six groups of
questions. Each campaign will be a set of experimental, theoretical, and
computational activities formulated to address one of the six groups of
questions during the next decade. The campaigns will employ a variety of
experiments that span a range of configurations and sizes. This is the
optimal approach for two reasons. First, experiments with differing
configurations and a range of important physical parameters are needed
to identify how these factors affect plasma behavior. Second, there are
a variety of possible attractive approaches to both magnetic and
inertial fusion, and a study of a portfolio of configurations will help
to identify an optimal approach. The six campaigns are described below.

**1. Macroscopic Plasma Physics**

The macroscopic behavior of magnetically confined plasma is due to the
nonlinear interaction of the plasma with the confining magnetic field,
electric fields, and plasma flows. These are determined by the transport
and confinement of the plasma, the presence of instabilities, and the
generation of plasma currents. This interaction of the plasma and the
fields determines the maximum pressure that can be confined in a given
magnetic field configuration, and, thereby, the maximum fusion power
that can be produced. This campaign focuses on questions 1-3 in the list
above and includes the following emphases:

-   Understand the role of magnetic field structure in plasma
    confinement through experiments on the existing major U.S.
    facilities, a variety of smaller experiments, and the National
    Compact Stellarator Experiment (when completed), and through
    analytic theory, and advanced simulation.

-   Understand the processes that limit the maximum pressure that can be
    confined and how to apply external controls to extend these limits
    through experiment, theory, and advanced simulation.

**2. Multi-scale Transport Physics**

The study of dynamical processes in magnetized plasmas is one of the
"grand challenges" of physics. Complexity arises from the extremely wide
range of spatial and temporal scales, strong intrinsic nonlinearities,
and the importance of geometric detail. Even in plasmas that are free
from macroscopic instabilities, the free energy from the plasma pressure
or rotational motion drives small-scale turbulence that dominates
energy, momentum, and particle transport across the confining magnetic
field. The goal of this campaign is to answer questions 4-6 in the list
above and includes the following emphases:

-   Identify the dominant transport mechanisms for heat, particles, and
    momentum in magnetically confined plasmas and seek to develop a
    predictive capability for transport in fusion plasmas through
    comprehensive comparisons between experiment, theory and simulation.

-   Understand the generation of flow shear, regulation of turbulence,
    and self-consistent profile dynamics and identify conditions for
    edge and core transport barrier formation.

-   Explore and understand the dominant driving and damping mechanisms
    for large-scale and zonal flows through detailed measurements of
    transport barriers, advances in theory, and targeted experiments in
    simple configurations.

-   Identify the mechanisms and structure of magnetic reconnection
    through comparisons of reconnections in laboratory and astrophysical
    plasmas and detailed 3-D nonlinear simulations.

**3. High Energy Density Physics**

High energy density plasmas of interest for inertial fusion have vastly
different spatial and temporal scales from magnetic fusion plasmas, and
different physics as well. High energy density plasmas are characterized
by energy densities exceeding 100 kilojoules per cubic centimeter, or
equivalently, pressures exceeding one megabar---conditions achieved in
the center of stars and giant planets. This campaign concentrates on
activities pertaining to heavy-ion-driven high energy density physics,
fast ignition high energy density physics, and magnetized plasma-liner
high energy density physics. It focuses on questions 7-9 in the list
above and includes the following emphases:

-   Depend on DOE's National Nuclear Security Administration's (NNSA)
    National Ignition Facility, which is expected to achieve its full
    energy within five years, to demonstrate target ignition in about a
    decade, and combined with other experiments, lead to a future
    inertial fusion Engineering Test Facility.

-   Use existing experimental facilities, with modest upgrades, to test
    the limits of longitudinal and transverse compression of neutralized
    heavy ion beams and use this information to design an Integrated
    Beam Experiment (IBX).

**4. Plasma-Boundary Interfaces**

The physics of the thin transitional plasma that connects the hot core
plasma (at a temperature of more than 100 million degrees Celsius) with
the much lower temperature (300-1500 degrees Celsius) material walls of
the fusion device is the subject of this campaign. Within this
few-centimeter-wide region, the magnetic field topology changes from
closed magnetic surfaces to open field lines, large electric fields form
spontaneously, magnetohydrodynamic stability continuously evolves, and
the plasma transport changes dramatically. At the walls, the plasma on
the open field lines interacts with the material surfaces through
complex surface chemistry, multi-step ionization processes, and
multi-species ion and neutral transport, all of which depend on the
material surface composition and geometry.

Small changes in the equilibrium of the boundary can dramatically affect
the overall performance of a burning plasma. Understanding the dynamics
of this boundary region, which involves time scales spanning six orders
of magnitude and spatial scales from microns to meters, sufficiently
well to reliably predict the behavior of a burning plasma experiment is
one of the greatest challenges facing the fusion community. This
campaign seeks to answer question 10 in the list above and includes the
following emphases:

-   Develop the capability to predict the magnetohydrodynamic stability
    and plasma parameters of the ITER edge region with high confidence.

-   Identify the underlying mechanisms for cross field transport in the
    edge plasma region and resolve the key boundary physics issues
    governing the selection of plasma facing components for ITER.

**5. Waves and Energetic Particles**

A plasma can support a vast array of electromagnetic waves not possible
in other states of matter. These waves may arise spontaneously or be
excited by external sources. Waves and plasma particles can be strongly
coupled through resonant interactions, which can accelerate the
particles, thereby increasing the plasma temperature and electric
current, or drive mass flows with application to steady-state,
high-performance operation. Conversely, the energetic alpha particles in
a burning plasma can excite unstable waves and turbulence in the plasma,
causing particle and energy loss. Under other conditions, the alpha
particles in a burning plasma can establish favorable conditions for
self-sustained fusion burn and possibly control certain bulk plasma
instabilities. This campaign focuses on scientific questions 11-12 in
the list above and includes the following emphases:

-   Make detailed diagnostic measurements and non-linear, closed-loop
    simulations to understand the macroscopic plasma responses produced
    by wave-particle interactions, including local current generation,
    plasma flows, and heating.

-   Develop scenarios using radio-frequency waves to optimize plasma
    confinement and stability through focused experiments benchmarked
    with simulations that integrate wave coupling, propagation, and
    absorption physics with transport codes and magnetohydrodynamic
    stability codes.

-   Improve analysis and simulations to match the experimental
    measurements of the dynamics of energetic particle-excited modes and
    scale the understanding to predict the dynamics of these modes in
    advanced regimes of operation with high pressure, inverted magnetic
    field shear, and strong plasma flow.

**6. Fusion Engineering Science**

The fusion program has long depended on and benefited from advances in
technologies for heating and current drive, stabilization, and fueling,
as well as advances in magnet technology and high heat flux materials.
As the United States prepares to collaborate in the exploration of
deuterium-tritium burning plasmas, the importance of establishing the
material and plasma chamber engineering science moves to the forefront
of technology issues. The plasma chamber with its plasma-facing,
blanket, and structural materials must provide simultaneously for power
extraction; tritium breeding, extraction, and control; structural
integrity; acceptably high performance and reliability at high
temperature; and maintainability under extreme conditions of heat and
particle fluxes, energetic neutrons, intense magnetic fields, and large
mechanical and electromagnetic forces. These components and materials
surrounding the plasma must be compatible with plasma stability and
exhibit favorable safety and environmental features, while withstanding
an environment significantly harsher than in any existing nuclear
system. This campaign aims to answer questions 13-15 in the list above
and includes the following emphases:

-   Develop the plasma-facing materials and the other technologies
    required to support the planned U.S. fusion research program and the
    U.S. contributions to ITER.

-   Develop and deliver to ITER the blanket test modules required to
    understand the behavior of materials and blankets in the integrated
    fusion environment.

-   Determine the plasma operating regimes and nuclear, material, and
    technological conditions in which tritium self-sufficiency and power
    extraction can be attained in a fusion device.

-   Design materials at the molecular scale to create innovative
    materials that possess the necessary high performance properties for
    the plasma chamber and other systems, leveraging investments in our
    Fusion Energy Sciences program with the materials research of our
    Basic Energy Sciences program.

-   Create additional facilities, as may be needed, to follow the ITER
    project, for testing materials and components for high duty-factor
    operation in a fusion power plant environment.

**Relationship between the campaigns and the overarching themes**

The three overarching themes express the primary motivations for fusion
energy science research and also provide a cross-cutting framework to
organize research activities in the six scientific campaigns. The first
overarching theme---understand matter in the high temperature plasma
state---encompasses the search for the fundamental understanding needed
for the other two themes. It also relates to the development of the
fundamental principles needed to understand a wide range of
astrophysical, laboratory, and industrial plasmas. The second of these
themes---create a star on earth---comprises the more focused research
and engineering activities needed to build magnetic and inertial burning
plasma research facilities and carry out successful burning plasma
research programs on these facilities. The final theme---develop the
science and technology to realize fusion energy---consists of the
specific fusion science and engineering research required to develop an
economically and environmentally attractive fusion power plant.

Each of the six campaigns in our plan concentrates on activities that
answer one or more of the fifteen high priority questions of today's
Fusion Energy Sciences program. However, taken together, these research
activities will also advance our fundamental **understanding of matter
in the high-temperature plasma state** and will contribute ideas of
importance to other fields of science. For example, understanding
macroscopic plasma physics will provide critical insights into the
dynamics of plasmas confined in the complex magnetic fields within the
solar magnetic arcades, in jets emanating from black holes, and in
extra-galactic regions. Similarly, multi-scale transport was first
explored in the fusion program as an issue of importance to fusion
experiments; however, it is now viewed as a fundamental process in
phenomena such as the transport of solar wind plasma into the Earth's
magnetosphere and the transport of angular momentum in astrophysical
accretion disks. In addition, research on high energy density plasmas
contributes to research on particle beam physics, intense
radiation-matter interaction physics, stellar physics, and astrophysics.
Fusion engineering science, which enables the fundamental research in
fusion science, contributes to materials science, plasma-surface
interaction, and plasma chemistry.

The campaigns related to **creating a star on earth** can significantly
advance the research program in ITER by providing the information needed
to make remaining design decisions. Planned research on advanced
operating modes can provide the basis for higher gain and/or longer
pulse burning plasma operation. Further, the U.S. fusion program must
support the development of new measurement techniques or the adaptation
of current measurement techniques to make the measurements needed to
understand a burning plasma. The development of an integrated simulation
capability will be a major asset to planning operating scenarios and
experiments on ITER. Finally, research in fusion engineering science is
needed to provide the power and particle exhaust, fueling, tritium
handling, auxiliary heating and current drive, shielding and other
systems needed for long-pulse, high-power operation and to provide the
blanket modules for tritium and energy extraction tests. Planned
research on high energy density plasmas can provide the information
needed to plan inertial fusion energy related experiments for the
National Ignition Facility, funded by NNSA.

**Realizing fusion energy** is a grand scientific and technical
challenge. In magnetic fusion there is a highly nonlinear interaction
between the plasma and the magnetic field configuration confining the
plasma, and in inertial fusion the interaction occurs between the plasma
and the energetic radiation compressing the plasma. In a fusion power
plant, there will be a similarly complex interaction between the burning
plasma and the plasma chamber responsible for extracting heat and
breeding tritium. The highly nonlinear interaction between the different
scientific and technical issues creates scientific opportunities and
challenges. As with the previous themes, all six campaigns contribute to
realizing fusion power. For example, understanding macroscopic plasma
physics is essential to optimizing magnetic confinement, while
understanding multi-scale transport is necessary to maximize the energy
gain of fusion energy systems. Controlling the plasma boundary
interfaces is important both to optimize the plasma performance and to
obtain adequate lifetime of plasma-facing components. Understanding the
physics of waves and energetic particles is necessary to achieving
advanced, steady-state operating modes and controlling self-heated
plasmas. Investigating the many issues related to high energy density
plasmas, such as heavy ion beam physics, fast ignition, and magnetized
plasma-liner implosions, is necessary to realizing inertial fusion
energy. Finally, successfully addressing many issues in fusion
engineering science, such as blanket systems for power extraction and
tritium breeding, low activation materials, real-time control systems,
and efficient heating and current drive systems, is critical to
realizing fusion energy.

**Our Timeline and Indicators of Success**

Our commitment to the future and to the realization of the fusion energy
goal in the Office of Science Strategic Plan
([www.sc.doe.gov/sub/Mission/Strategic_Plan/Feb-2004-Strat-Plan-screen-res.pdf](http://www.sc.doe.gov/sub/Mission/Strategic_Plan/Feb-2004-Strat-Plan-screen-res.pdf)):
**Bring the Power of the Stars to Earth**, is reflected not only in our
strategies, but also in our Key Indicators of Success listed below, and
in our Strategic Timeline for Fusion Energy Sciences at the end of this
plan.

Our FES Strategic Timeline charts a collection of important,
illustrative milestones, representing planned progress within each
overarching theme. These milestones, while subject to the rapid pace of
change and uncertainties in all science programs, reflect our latest
perspective for the next 20 years and beyond.

Additionally, the Office of Science has identified Key Indicators of
Success, designed to gauge our overall progress toward achieving the
realization of fusion power. These select indicators, identified below,
are representative long-term measures against which progress can be
evaluated over time. The specific features and parameters of these
definitions of success can be found on the web at
[www.sc.doe.gov/measures](http://www.science.doe.gov/measures).

**Key Indicators of Success**

-   Progress in developing a predictive capability for key aspects of
    burning plasmas, using advances in theory and simulation benchmarked
    against a comprehensive experimental database of stability,
    transport, wave-particle interaction, and edge effects.

-   Progress in demonstrating enhanced fundamental understanding of
    magnetic confinement and in improving the basis for future burning
    plasma experiments through research on magnetic confinement
    configuration optimization.

-   Progress in developing the fundamental understanding and
    predictability of high energy density plasmas, including potential
    energy producing applications.

**Strategic Timeline**

**Theme 1: Understand matter in the high-temperature plasma state**

Achieve long-duration, high-pressure, well-confined plasmas in a
spherical torus sufficient to begin design of a Next Step Spherical
Torus **(2008)**

Refine theoretical and experimental understanding of transport,
stability, wave-plasma interactions, and edge effects in tokamaks
**(2009)**

Begin fabrication on the Next Step Spherical Torus to test an advanced
fusion concept for magnetically confining a fusion reaction **(2010)**

Evaluate the ability of the compact stellarator configuration to confine
a high temperature plasma **(2012)**

Create and measure properties of high energy density plasmas using
intense ion beams, dense plasma beams, and lasers **(2012)**

Make significant progress toward developing the fundamental
understanding and predictability of high energy density plasma physics
**(2015)**

Advance plasma science and computer modeling to obtain a comprehensive,
and fully validated, plasma configuration simulation capability for
magnetically confined plasmas that enables the design of fusion power
plants **(2020)**

Determine the potential of one or more of the promising plasma
configurations (e.g. a spherical torus) for use as a component test
facility of a fusion power source **(2020)**

**Theme 2: Create a star on earth**

Begin the U.S. Contributions to ITER project for this international
collaboration to build the first fusion burning plasma experiment
capable of a sustained fusion reaction **(2006)**

Demonstrate use of active plasma controls and self-generated plasma
current to achieve high-pressure/well-confined steady-state operation
for ITER **(2009)**

Initiate design and fabrication of the first test blanket module to be
installed on ITER **(2011)**

Evaluate discharge scenarios for ITER based on major tokamak results
**(2012)**

Begin ITER operation (**2014)**

Make significant progress toward developing a predictive capability for
key aspects of burning plasmas using advances in theory and simulation
benchmarked against a comprehensive experimental database of stability,
transport, wave-particle interaction, and edge effects **(2015)**

Complete ITER experiments to determine plasma confinement in the
parameter range required for an energy producing plasma **(2017)**

Complete experiments on ITER to determine the impact of fusion alpha
particle heating on the stability of energy-producing plasmas **(2020)**

**Theme 3: Develop the science and technology to realize fusion energy**

Begin fabrication of an intermediate-scale, Integrated Beam Experiment
(IBX) to understand how to generate and transmit the focused, high
energy ion beam needed to power an inertial fusion energy (IFE) reaction
**(2009)**

Deliver to ITER the blanket test models needed to demonstrate the
feasibility of extracting energy at high temperature from burning
plasmas and achieving a self-sufficient fuel cycle **(2013)**

Achieve high fusion power for long durations on ITER to define the
engineering requirements for fusion power plants **(2025)**