Abstract

In the field of inertial confinement fusion, non-uniform illumination of beams is a significant factor contributing to the non-uniform implosion of the target. Researchers have shown interest in direct-drive heavy ion beams due to their high efficiency in accelerating particles. To ensure the consistent operation of fusion reactors, it is essential to achieve robustness in target implosion. As a proposed solution, this paper investigates the impact of beam radius variation and wobbling frequency on target gain in heavy ion beam illumination. The study specifically examines the effects of beam radius variation and wobbling frequency on target gain. In one case, the wobbling frequency is set at 438 MHz, and the pulse radius is increased from 3.8 to 4.2 mm. The investigation involves analyzing the evolution of RMS nonuniformity in target layers. The results indicate that although increasing the beam radius leads to a slight rise in energy deposition non-uniformity, it still results in an overall increase in target gain of approximately 13%. Additionally, calculations are conducted for a wobbling frequency of 453 MHz. The findings demonstrate that increasing the beam radius from 3.8 to 4 mm, similar to the previous case, increases the target gain by approximately 7%. However, further increasing the radius to 4.2 mm causes a decrease in target gain due to the misalignment of a fraction of the heavy ion beam particles with the target. These results suggest that adjusting the beam radius and wobbling frequency can have a notable impact on target gain in heavy ion beam illumination. By carefully selecting these parameters, it is possible to enhance target implosion uniformity and improve fusion performance. The findings presented in this paper contribute to the understanding of beam-target interactions in inertial confinement fusion and offer insights for optimizing heavy ion beam illumination techniques in future fusion experiments.

中文翻译：

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直驱重离子聚变中束流半径和摆动频率对靶内爆均匀性的影响

摘要

在惯性约束聚变领域，光束的不均匀照明是导致目标不均匀内爆的重要因素。研究人员对直接驱动重离子束表现出兴趣，因为它们在加速粒子方面效率很高。为了确保聚变反应堆的持续运行，必须实现目标内爆的鲁棒性。作为提出的解决方案，本文研究了重离子束照明中光束半径变化和摆动频率对目标增益的影响。该研究专门研究了光束半径变化和摆动频率对目标增益的影响。在一种情况下，摆动频率设置为438 MHz，脉冲半径从3.8毫米增加到4.2毫米。该调查涉及分析目标层中均方根不均匀性的演变。结果表明，虽然增加光束半径会导致能量沉积不均匀性略有上升，但仍然导致靶增益总体增加约 13%。此外，还对 453 MHz 的摆动频率进行了计算。研究结果表明，与之前的情况类似，将光束半径从 3.8 毫米增加到 4 毫米，可使目标增益增加约 7%。然而，由于部分重离子束粒子与目标未对准，进一步将半径增加到 4.2 毫米会导致目标增益降低。这些结果表明，调整光束半径和摆动频率可以对重离子束照明中的目标增益产生显着影响。通过仔细选择这些参数，可以增强目标内爆均匀性并改善聚变性能。本文提出的研究结果有助于理解惯性约束聚变中的束-目标相互作用，并为未来聚变实验中优化重离子束照明技术提供见解。