D-Cluster Converter Foil for Laser-Accelerated Deuteron Beams: Towards Deuteron-Beam-Driven Fast Ignition

Using a laser/particle pulse to ignite a pre-compressed ICF target, or Fast Ignition (FI), has gained its popularity in the recent decade since it not only reduce the required laser driven energy to ignite the ICF fuel, but also relax the symmetry requirements for compression (reducing instabilities), and significantly increase the fusion energy gain. Among various choices of particle beams, ion beam is especially appealing due to its almost straight trajectory, making it easily focused in the hot spot. However, the current ion-driven FI encounters various problems for converter-foil based FI, such as depletion problems for proton-driven FI, and high energy consumption problem for Carbon-driven FI. Although high density deuteron beam was considered for this application as well, the proposed method of deuteron generation, direct laser plasma interaction, involves tremendous instabilities.We propose to use the volumetrically-loaded ultra-high-density deuterium cluster material for converter-foil based deuteron beam generation. Due to its volumetric loading, the material will provide enough deuteron beam flux for fuel ignition, avoiding depletion problem encountered by current proton-driven FI. In addition, accelerated deuterons will fuse with the ICF fuel (both D and T) to provide extra bonus energy gain which further relax the laser energy needed. Commercial Applications and Other Benefits: If successful, it will establish the basis for developing a target factory for these ultra-high-density deuterium cluster targets to support the evolving ICF power industry envisioned after successful ignition at NIF predicted in 1~1 years. While the commercialization of ICF power plants would still be some years, the cluster converter foil would be in high demand for experiments performed in supporting its development. With the proposed collaborated effort by NPL and Lockheed Martin, this target factory will greatly accelerate the ICF research of United States, and realize near-term fusion commercialization