An interim report from the National Research Council published by the National Academy of Sciences says that while much progress has been made in the quest for fusion energy in the last decade, critical scientific and technical challenges remain. The report, "An Assessment of the Prospects for Inertial Fusion Energy," reviewed recent work in inertial confinement fusion (ICF) and received technical input describing advances on many fronts, including indirect-drive and direct-drive fusion schemes, heavy-ion-beam focusing and pulse compression, and advances in pulsed-power fusion.
The report encourages the establishment of a scientific-community-based roadmap for the development of fusion energy sources, utilizing university-based researchers already involved, but also "drawing on a broader set of technical expertise in micro-fabrication, materials, laser, accelerator, and pulsed-power disciplines."
Noting that the current National Ignition Facility (NIF, shown in photo) experiments are not specifically designed to be suitable for inertial fusion energy (IFE) applications, the report nevertheless suggested that many experiments could be done to provide "experimental validation of predictive capabilities."
SPIE Newsroom has published videos on the status of the NIF quest for fusion, most recently an interview with program director for Laser Fusion Energy, Mike Dunne. SPIE will also host a conference on "Target Diagnostics Physics and Engineering for Inertial Confinement Fusion" at SPIE Optics + Photonics symposium, 12-16 August 2012 in San Diego.
In an earlier interview with SPIE, Edward Moses, principal associate director for the NIF and Photon Science Directorate at Lawrence Livermore National Laboratory, emphasized the importance of the components and technologies developed specifically for the NIF, such as neodymium-doped phosphate glass, used as a gain medium. Other advances include large-aperture optical switches, high-performance deformable mirrors and large, rapid-growth KDP crystals.
The report says that there is no nationally coordinated R&D program for IFE in the United States incorporating the spectrum of driver approaches (diode-pumped lasers, heavy ions, krypton fluoride lasers, pulsed power, or other concepts), both indirect-drive and direct-drive target designs, or any of the unique technologies needed to extract energy from any of the variety of driver and target options.
Research in these various approaches is conducted across multiple labs and universities, according to the report, although the driver approaches are usually identified with the following institutions:
- Diode-pumped solid-state lasers (Lawrence Livermore National Laboratory and the Laboratory for Laser Energetics at the University of Rochester)
- Pulsed power (Sandia National Laboratories)
- Heavy-ion fusion (Lawrence Berkeley National Laboratory)
- Magnetized target fusion (Los Alamos National Laboratory)
- Krypton-fluoride lasers (Naval Research Laboratory)
The final report of the present study, expected this summer, will evaluate the current status and future prospects for ICF to contribute to the U.S. electricity generation mix.