Fusion energy with lasers, direct drive targets, and dry wall chambers

Abstract

A coordinated, focused effort is underway to develop Laser Inertial Fusion Energy. The key components are developed in concert with one another and the science and engineering issues are addressed concurrently. Recent advances include: target designs have been evaluated that show it could be possible to achieve the high gains (>100) needed for a practical fusion system.These designs feature a low-density CH foam that is wicked with solid DT and over-coated with a thin high-Z layer. These results have been verified with three independent onedimensional codes, and are now being evaluated with two-and three-dimensional codes. Two types of lasers are under development: Krypton Fluoride (KrF) gas lasers and Diode Pumped Solid State Lasers (DPSSL). Both have recently achieved repetitive 'first light', and both have made progress in meeting the fusion energy requirements for durability, efficiency, and cost. This paper also presents the advances in development of chamber operating windows (target survival plus no wall erosion), final optics (aluminium at grazing incidence has high reflectivity and exceeds the required laser damage threshold), target fabrication (demonstration of smooth DT ice layers grown over foams, batch production of foam shells, and appropriate high-Z overcoats), and target injection (new facility for target injection and tracking studies).

A Review of the U.S. Department of Energy's Inertial Fusion Energy Program

“…In the case of the HAPL targets [7], the feasibility of producing foam capsules of appropriate dimensions and density on a batch production basis has been demonstrated. Further work is needed to improve capsule quality, reproducibility and largescale production.…”

“…Highlights of Recent Progress: The mercury laser program [7] has activated and operated one of two amplifier heads. In operation at the fundamental wavelength of 1053 nm, Mercury has achieved 34 J in a 15 ns single-shot, and 23 J at 5 Hz for 10 4 shots.…”

Conceptual design of fast-ignition laser fusion reactor FALCON-D

“…For example, KOYO-Fast has 20 m and 30 m distance from the reactor core to the final optics for implosion beam and heating beam, respectively [12]. On the other hand, a grazing incidence metallic mirror (GIMM), which prevents the final optics from the direct expose by the high energy neutron, has also been proposed in the HAPL program [13]. Nevertheless, the final optics is supposed to be damaged by the neutron irradiation, and the easy replacement method of the final optics is required and essential.…”

Feasibility of Hydrogen Production Using Laser Inertial Fusion as the Primary Energy Source

“…Fullsize components will be developed, tested, and integrated during the second phase, which is expected to last until 2013-14. The third phase will see the construction, operation, and testing of a demonstration fusion energy plant, originally conceived as a 300-to-700-MW e net Experimental Test Facility (ETF) operating by 2020 [Sethian and Obenschain (2003)]. This has recently been scaled back to a 150-MW th Fusion Test Facility (FTF) that could be running by 2018 [Sethian and Obenschain (2005)].…”