Nonuniformity mitigation of beam illumination in heavy ion inertial fusion

作者：Kawata, S.^*; Noguchi, K.; Suzuki, T.; Kurosaki, T.; Barada, D.; Ogoyski, A. I.; Zhang, W.; Xie, J.; Zhang, H.; Dai, D.

来源：Physica Scripta, 2014, 89(8): 088001.

DOI：10.1088/0031-8949/89/8/088001

• instability mitigation
• inertial confinement fusion
• fuel mixing
• heavy ion beam
• Rayleigh-Taylor instability

In inertial fusion, a target DT fuel should be compressed to typically 1000 times the solid density. The target implosion nonuniformity is introduced by a driver beam's illumination nonuniformity, for example. The target implosion should be robust against the implosion nonuniformities. In this paper, the requirement for implosion uniformity is first discussed. The implosion non-uniformity should be less than a few percent. The implosion dynamics is also briefly reviewed in heavy ion inertial fusion (HIF). Heavy ions deposit their energy inside the target energy absorber, and the energy deposition layer is rather thick, depending on the ion particle energy. Then nonuniformity mitigation mechanisms of the heavy ion beam (HIB) illumination in HIF are discussed. A density valley appears in the energy absorber, and the large-scale density valley also works as a radiation energy confinement layer, which contributes to a radiation energy smoothing. In HIF, wobbling heavy ion beam illumination was also introduced to realize a uniform implosion. The wobbling HIB axis oscillation is precisely controlled. In the wobbling HIBs' illumination, the illumination nonuniformity oscillates in time and space on an HIF target. The oscillating-HIB energy deposition may contribute to the reduction of the HIBs' illumination nonuniformity by its smoothing effect on the HIB illumination nonuniformity and also by a growth mitigation effect on the Rayleigh-Taylor instability.

• 出版日期2014-8
• 单位上海大学