Progress in the pulsed power inertial confinement fusion program

摘要

Pulsed power acceleratorsare being used in Inertial Confinement Fusion (ICF) research. In order to achieve the goal of a fusion yield in the range of 200-1000 MJ from radiation driven fusion capsules, it is generally believed that approx 10 MJ of the driver energy must be deposited within the ICF target in order to deposit approx 1 MJ of radiation energy in the fusion capsule. Pulsed power reprsents an efficient technology for producing both these energies and these radiation environments in the requireed short pulses (few tens of a nanosecond). Two possible approaches are being developed to utilize pulsed power accelerators in this effort: intense beams of light ions and z-pinches. The paper describes recent progress in both approaches. Over the past several years, experiments have successfully answered many questions critical to ion target design. Increasing the ion beam power and intensity is the next objective. Last year, the Particle Beam Fusion Accelerator II (PBFA II) was modified to generate ion beams in a geometry that will be required for high yield applications. This modification has resulted in the production of the highest power ion beam to be accelerated from an extraction ion diode. Fast magnetically driven implosions (z-pinches) as platforms for ICF ablator physics and EOS experiments are also evaluated. The z-pinch implosions driven by the 20 TW Staurn accelerator have efficiently produced high x-ray power (> 75 TW) and energy (>400 kJ). Containing these x-ray sources within a hohlraum produces a unique large volume (>6000 mm~3), long lived (>20 ns) radiation environment. In addition to studying fundamental ICF capsule physics, there are several concepts for driving ICF capsules with these x-ray sources. Progress in increasing the x-ray power on the Saturn accelerator and promise of further increases on the higher PBFA II accelerator will be described.