Local measurements of correlated momentum and heat transport in the TFTR tokamak

Simultaneous profile measurements of the toroidal rotation speed and ion temperature during unbalanced neutral beam injection in the Tokamak Fusion Test Reactor show that the ion momentum and thermal diffusivities are comparable in magnitude (${\mathrm{\ensuremath{\chi}}}_{\mathrm{\ensuremath{\varphi}}}$\ensuremath{\approxeq}1.5${\mathrm{\ensuremath{\chi}}}_{\mathrm{i}}$) and vary similarly with plasma current and minor radius. The correlation of ${\mathrm{\ensuremath{\chi}}}_{\mathrm{\ensuremath{\varphi}}}$ and ${\mathrm{\ensuremath{\chi}}}_{\mathrm{i}}$ is consistent with anomalous transport driven by collisionless electrostatic microinstabilities including ion-temperature-gradient-driven modes (${\mathrm{\ensuremath{\eta}}}_{\mathrm{i}}$ modes) and collisionless trapped-electron modes.