Does the helicity barrier control ion heating in imbalanced solar wind?

In imbalanced Alfvenic turbulence (normalized cross helicity $\sigma_c$ near 1) at $\beta$ below about 1, conservation of generalized helicity blocks the cascade at $k\rho_i \sim 1$ (the helicity barrier), causing a steep transition range in the magnetic spectrum and ion heating by ion-cyclotron waves. Determine whether this mechanism sets the transition-range steepness, ion-cyclotron wave occurrence and $Q_i/Q_e$ as functions of $\sigma_c$ and $\beta_i$ in the solar wind, and its threshold in $\beta$. An answer is spacecraft statistics showing or excluding the predicted dependences.

Parker Solar Probe and Solar Orbiter statistics of the spectral transition, ion-cyclotron wave occurrence and ion heating versus $\sigma_{c}$ and $\beta_{i}$ matching hybrid-kinetic predictions.