Alfvén Eigenmode stability measurements in recent JET H, D, T, and DT plasmas*

We present Alfvén Eigenmode stability measurements (frequencies, damping rates γ<0, and toroidal mode numbers) from hundreds of H,D,T, and DT plasmas in the 2019-21 JET campaigns. Data are collected by eight in-vessel, toroidally spaced antennas [Panis NF 10] independently powered/phased [Puglia NF 16] to resonate with stable AEs [Fasoli PRL 95]. The system recently demonstrated improved performance during high-power heating [Tinguely NF 21a] and X-point configuration [Tinguely NF 21b] compared to the previous system's operation during early JET campaigns, including 1997 DT [Fasoli PoP 00]. Contributions to γ from various drive/damping mechanisms (especially from alphas) are assessed through MHD, kinetic, and gyrokinetic simulations, allowing extrapolation to future fusion devices. Importantly, knowledge gained from a range of isotope mixes, plus significant He fractions, can be transferred to pre-fusion and DD/DT ITER operations.