Thermal imaging diagnostics was used as a surface temperature mapping tool to characterize the energy density distribution of a high-intensity pulsed ion beam. This approach was tested on the TEMP-6 accelerator (200–250 kV, 150 ns). The beam composition included carbon ions (85%) and protons, and the energy density in the focus was 5–12 J/cm2. Targets of stainless steel, titanium, brass, copper, and tungsten were examined. Our observations show that the maximum energy density measured with the thermal imaging diagnostics considerably exceeds the ablation threshold of the targets. An analysis of the overheating mechanisms of each target was carried out, including metastable overheating of the target to above its boiling temperature during rapid heating; formation, migration, and the subsequent annealing of fast radiation-induced defects in the target under ion beam irradiation. This expands the range of energy density measurement for this thermal imaging diagnostics from 2–3 J/cm2 up to 10–12 J/cm2 but introduces error into the results of measurement. For a stainless steel target, this error exceeds 15% at an energy density of more than 4 J/cm2. A method of correcting the results of the thermal imaging diagnostics is developed for a pulsed ion beam under conditions of intense ablation of the target material.

中文翻译：

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扩展高强度脉冲离子束热成像诊断的测量范围

使用热成像诊断程序作为表面温度映射工具来表征高强度脉冲离子束的能量密度分布。此方法已在TEMP-6加速器（200–250 kV，150 ns）上进行了测试。束组成包括碳离子（85％）和质子，焦点处的能量密度为5-12 J / cm 2。检查了不锈钢，钛，黄铜，铜和钨的靶材。我们的观察结果表明，使用热成像诊断仪测得的最大能量密度大大超过了目标的消融阈值。对每个靶材的过热机理进行了分析，包括在快速加热过程中靶材的亚稳态过热至其沸腾温度以上；以及 离子束辐照下靶材中快速辐射诱导的缺陷的形成，迁移和随后的退火。这将这种热成像诊断的能量密度测量范围从2–3 J / cm 2扩展到10–12 J / cm 2但会在测量结果中引入误差。对于不锈钢靶，在能量密度大于4 J / cm 2时，此误差超过15％。针对靶材料的强烈烧蚀条件下的脉冲离子束，开发了一种校正热成像诊断结果的方法。