Fast ion physics is an active field of research in the fusion community, but most studies focus on deuterium fast ions. The generation and investigation of energetic helium in present devices, however, provide significantly more insight on how the fast alpha particles produced from fusion reactions, will behave in future reactor plasmas. Fast helium ion populations can be measured with charge exchange recombination spectroscopy (CXRS) in the wings of the helium spectral line (He II n = 4–3, 468.6 nm) providing information on their distribution function. CXRS measurements of energetic ³He ions, a first for ASDEX Upgrade, are presented. The ³He ions are accelerated to high energies by a three-ion cyclotron resonance frequency (ICRF) heating scenario in a mixed hydrogen–deuterium plasma. The spectral signature of the energetic helium ions in the charge exchange spectra is presented and compared with the theoretical predictions obtained with the TORIC-SSFPQL code. The magnitude of the predicted charge exchange spectral radiance, obtained via forward-modelling of the spectrum utilising TORIC-SSFPQL distribution functions, and the expected energies of the ions agree well with the measurement, confirming that the spectral feature is due to ICRF-accelerated ³He ions. Comparisons between the experimental measurement and the modelling reveal discrepancies that illuminate details of the velocity distribution function of these ions.

快速离子物理学是聚变界研究的活跃领域，但大多数研究集中在氘快速离子上。然而，目前装置中高能氦气的产生和研究，为由聚变反应产生的快速α粒子在未来反应堆等离子体中的行为提供了更多的见识。快速氦离子种群可通过氦光谱线（He II n = 4–3，468.6 nm）两翼的电荷交换复合光谱法（CXRS）进行测量，从而提供有关其分布功能的信息。介绍了高能³ He离子的CXRS测量，这是ASDEX升级的首例。在³在氢-氘混合等离子体中，三离子回旋共振频率（ICRF）加热方案将He离子加速为高能。给出了电荷交换光谱中高能氦离子的光谱特征，并将其与通过TORIC-SSFPQL代码获得的理论预测进行了比较。通过使用TORIC-SSFPQL分布函数对光谱进行正向建模获得的预测的电荷交换光谱辐射度的大小以及离子的预期能量与测量结果吻合得很好，证实了光谱特征是由于ICRF加速引起的³他离子。实验测量与建模之间的比较揭示了差异，这些差异阐明了这些离子的速度分布函数的细节。