  The fast solar wind emerging from coronal holes is likely heated and
accelerated by the dissipation of magnetohydrodynamic turbulence, but the
specific kinetic mechanism resulting in the perpendicular ion heating required
by observations is not understood. A promising mechanism has been proposed by
Chandran et al. (2010), which in this paper we call "magnetic moment breaking"
(MMB). As currently formulated, MMB dissipation operates only on the ion
perpendicular motion, and does not influence their parallel temperature. Thus,
the MMB mechanism acting by itself produces coronal hole proton distributions
that are unstable to the ion-cyclotron anisotropy instability. This quasilinear
instability is expected to operate faster than the nonlinear turbulent cascade,
scattering ions into the parallel direction and generating
quasi-parallel-propagating ion-cyclotron (IC) waves. To investigate the
consequences of this instability on the MMB-heated protons, we construct a
homogeneous model for protons with coronal hole properties. Using a simplified
version of the resonant cyclotron interaction, we heat the protons by the MMB
process and instantaneously scatter them to lower anisotropy while
self-consistently generating parallel-propagating IC waves. We present several
illustrative cases, finding that the extreme anisotropies implied by the MMB
mechanism are limited to reasonable values, but the distinctive shape of the
proton distribution derived by Klein & Chandran (2016) is not maintained. We
also find that these combined processes can result in somewhat higher particle
energization than the MMB heating alone. These quasilinear consequences should
follow from any kinetic mechanism that primarily increases the perpendicular
ion temperature in a collisionless plasma.
