Wayne R. Meier

An Updated Point Design for Heavy Ion Fusion

Abstract An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant.

Osiris and SOMBRERO inertial fusion power plant designs–summary, conclusions, and recommendations

Abstract An 18 month study to evaluate the potential of inertial fusion energy (IFE) for electric power production has been completed. The primary objective of the study was to provide the US Department of Energy with an evaluation of the potential of inertial fusion for electric power production. The study included the conceptual design of two inertial fusion power plants. Osiris uses an induction linac heavy ion beam driver, and SOMBRERO uses a krypton fluoride laser driver. Conceptual designs were completed for the reactors, power conversion and plant facilities, and drivers. Environmental and safety aspects, technical issues, technology development needs, and economics of the final point designs were assessed and compared. This paper summarizes the results and conclusions of the conceptual designs and results of the assessment studies. We conclude that IFE has the potential of producing technically credible designs with environmental, safety, and economics characteristics that are just as attractive as magnetic fusion. Realizing this potential will require additional research and development on target physics, chamber design, target production and injection systems, and drivers.

Development Path for Z-Pinch IFE

Abstract The long-range goal of the Z-Pinch IFE program is to produce an economically-attractive power plant using high-yield z-pinch-driven targets (~3GJ) with low rep-rate per chamber (~0.1 Hz). The present mainline choice for a Z-Pinch IFE power plant uses an LTD (Linear Transformer Driver) repetitive pulsed power driver, a Recyclable Transmission Line (RTL), a dynamic hohlraum z-pinch-driven target, and a thick-liquid wall chamber. The RTL connects the pulsed power driver directly to the z-pinch-driven target, and is made from frozen coolant or a material that is easily separable from the coolant (such as carbon steel). The RTL is destroyed by the fusion explosion, but the RTL materials are recycled, and a new RTL is inserted on each shot. A development path for Z-Pinch IFE has been created that complements and leverages the NNSA DP ICF program. Funding by a U.S. Congressional initiative of

Timely Delivery of Laser Inertial Fusion Energy (LIFE)

4M for FY04 through NNSA DP is supporting assessment and initial research on (1) RTLs, (2) repetitive pulsed power drivers, (3) shock mitigation [because of the high yield targets], (4) planning for a proof-of-principle full RTL cycle demonstration [with a 1 MA, 1 MV, 100 ns, 0.1 Hz driver], (5) IFE target studies for multi-GJ yield targets, and (6) z-pinch IFE power plant engineering and technology development. Initial results from all areas of this research are discussed.

The Science and Technologies for Fusion Energy With Lasers and Direct-Drive Targets

Abstract The National Ignition Facility (NIF), the world’s largest and most energetic laser system, is now operational at Lawrence Livermore National Laboratory. A key goal of the NIF is to demonstrate fusion ignition for the first time in the laboratory. Its flexibility allows multiple target designs (both indirect and direct drive) to be fielded, offering substantial scope for optimization of a robust target design. In this paper we discuss an approach to generating gigawatt levels of electrical power from a laser-driven source of fusion neutrons based on these demonstration experiments. This “LIFE” concept enables rapid time-to-market for a commercial power plant, assuming success with ignition and a technology demonstration program that links directly to a facility design and construction project. The LIFE design makes use of recent advances in diode-pumped, solid-state laser technology. It adopts the paradigm of Line Replaceable Units utilized on the NIF to provide high levels of availability and maintainability and mitigate the need for advanced materials development. A demonstration LIFE plant based on these design principles is described, along with the areas of technology development required prior to plant construction.

An integrated systems model for heavy ion drivers

We are carrying out a multidisciplinary multi-institutional program to develop the scientific and technical basis for inertial fusion energy (IFE) based on laser drivers and direct-drive targets. The key components are developed as an integrated system, linking the science, technology, and final application of a 1000-MWe pure-fusion power plant. The science and technologies developed here are flexible enough to be applied to other size systems. The scientific justification for this work is a family of target designs (simulations) that show that direct drive has the potential to provide the high gains needed for a pure-fusion power plant. Two competing lasers are under development: the diode-pumped solid-state laser (DPPSL) and the electron-beam-pumped krypton fluoride (KrF) gas laser. This paper will present the current state of the art in the target designs and lasers, as well as the other IFE technologies required for energy, including final optics (grazing incidence and dielectrics), chambers, and target fabrication, injection, and tracking technologies. All of these are applicable to both laser systems and to other laser IFE-based concepts. However, in some of the higher performance target designs, the DPPSL will require more energy to reach the same yield as with the KrF laser.

INDUCTION ACCELERATOR ARCHITECTURES FOR HEAVY-ION FUSION

A source-to-target computer model for an induction linac driver for heavy ion fusion has been developed and used to define a reference case driver that meets the requirements of one current target design. Key features of the model are discussed, and the design parameters of the reference case design are described. Examples of the systems analyses leading to the point design are given, and directions for future work are noted.

Overview of US heavy ion fusion research

Abstract The approach to heavy-ion-driven inertial fusion studied most extensively in the US uses induction modulators and cores to accelerate and confine the beam longitudinally. The intrinsic peak-current capabilities of induction machines, together with their flexible pulse formats, provide a suitable match to the high peak-power requirement of a heavy-ion fusion target. However, as in the RF case, where combinations of linacs, synchrotrons, and storage rings offer a number of choices to be examined in designing an optimal system, the induction approach also allows a number of architectures, from which choices must be made. We review the main classes of architecture for induction drivers that have been studied to date. The main choice of accelerator structure is that between the linac and the recirculator, the latter being composed of several rings. Hybrid designs are also possible. Other design questions include which focusing system (electric quadrupole, magnetic quadrupole, or solenoid) to use, whether or not to merge beams, and what number of beams to use – all of which must be answered as a function of ion energy throughout the machine. Also, the optimal charge state and mass must be chosen. These different architectures and beam parameters lead to different emittances and imply different constraints on the final focus. The advantages and uncertainties of these various architectures will be discussed.

Integrated experiments for heavy ion fusion

Significant experimental and theoretical progress has been made in the U.S. heavy ion fusion program on high-current sources, injectors, transport, final focusing, chambers and targets for high energy density physics (HEDP) and inertial fusion energy (IFE) driven by induction linac accelerators. One focus of present research is the beam physics associated with quadrupole focusing of intense, space-charge dominated heavy-ion beams, including gas and electron cloud effects at high currents, and the study of long-distance-propagation effects such as emittance growth due to field errors in scaled experiments. A second area of emphasis in present research is the introduction of background plasma to neutralize the space charge of intense heavy ion beams and assist in focusing the beams to a small spot size. In the near future, research will continue in the above areas, and a new area of emphasis will be to explore the physics of neutralized beam compression and focusing to high intensities required to heat targets to high energy density conditions as well as for inertial fusion energy.

OPERATIONAL WINDOWS FOR DRY-WALL AND WETTED-WALL IFE CHAMBERS

Author(s): Barnard, J.J.; Ahle, L.E.; Bieniosek, F.M.; Celata, C.M.; Davidson, R.C.; Henestroza, E.; Friedman, A.; Kwan, J.W.; Logan, B.G.; Lee, E.P.; Lund, S.M.; Meier, W.R.; Sabbi, G.-L.; Seidl, P.A.; Sharp, W.M.; Shuman, D.B.; Waldron, W.L.; Qin, H.; Yu, S.S.