The aneutronic ¹¹B(p, α)2α fusion reaction driven by the interaction of high-energy lasers with matter has become a popular topic of research, since it represents a potential long-term goal alternative to the most studied deuterium-tritium reaction. However, the detection of the typical ionic products, especially alpha particles, of this low-rate fusion reaction is a challenging issue, due to their low flux. One of the diagnostic devices that can be implemented in laser-driven proton-boron fusion experiments is a Thomson spectrometer (TS), which is capable of detecting and discriminating ions according to their mass-to-charge ratio (, where is the mass number and is the atomic number of the ions). In this work, we report on the ultimate test of a TS, which was designed and developed at the ENEA Research Centre in Frascati, Italy, in the context of a p + ¹¹B fusion experiment. Our device—designed to have high sensitivity and a robust shielding against electromagnetic pulses (EMPs)—was implemented at the PALS laser facility (∼700 J in ∼350 ps pulses) at a distance of 367 mm from the laser-plasma interaction point. We analyse here the measured signals obtained with our device, focusing on the assessment of their signal-to-background ratio. Despite the presence of strong EMPs and background radiation at such a short distance from the laser-irradiated target, the TS proved to be suitable for effectively detecting protons and heavier ions stemming from the plasma source.

中文翻译：

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激光驱动低速无中子聚变反应实验中的高灵敏度汤姆逊光谱法

由高能激光与物质相互作用驱动的非中子 11 B ( p , α ) 2 ^α聚变反应已成为热门研究课题，因为它代表了替代研究最多的氘-氚反应的潜在长期目标. 然而，由于通量低，检测这种低速聚变反应的典型离子产物，尤其是 α 粒子是一个具有挑战性的问题。可以在激光驱动的质子-硼聚变实验中实施的诊断设备之一是 Thomson 光谱仪 (TS)，它能够根据离子的质荷比检测和区分离子 (，其中是质量数，是离子的原子序数）。^{在这项工作中，我们报告了 TS 的最终测试，该测试是在意大利弗拉斯卡蒂的 ENEA 研究中心在 ap + 11}的背景下设计和开发的 B融合实验。我们的设备设计具有高灵敏度和强大的电磁脉冲 (EMP) 屏蔽功能，在距离激光等离子体相互作用点 367 毫米的 PALS 激光设备（约 700 J in 约 350 ps 脉冲）中实施。我们在这里分析用我们的设备获得的测量信号，重点是评估它们的信号背景比。尽管在距激光照射目标如此短的距离处存在强 EMP 和背景辐射，但 TS 被证明适用于有效检测来自等离子体源的质子和较重的离子。