  Thermal fusion plasmas initiated by standing whistler waves are investigated
numerically by two- and one-dimensional Particle-in-Cell simulations. When a
standing whistler wave collapses due to the wave breaking of ion plasma waves,
the energy of the electromagnetic waves transfers directly to the ion kinetic
energy. Here we find that the ion heating by the standing whistler wave is
operational even in multi-dimensional simulations of multi-ion species targets,
such as deuterium-tritium (DT) ices and solid ammonia borane (H$_6$BN). The
energy conversion efficiency to ions becomes as high as 15% of the injected
laser energy, which depends significantly on the target thickness and laser
pulse duration. The ion temperature could reach a few tens of keV or much
higher if appropriate laser-plasma conditions are selected. DT fusion plasmas
generated by this method must be useful as efficient neutron sources. Our
numerical simulations suggest that the neutron generation efficiency exceeds
10$^9$ n/J per steradian, which is beyond the current achievements of the
state-of-the-art laser experiments. The standing whistler wave heating would
expand the experimental possibility for an alternative ignition design of
magnetically confined laser fusion, and also for more difficult fusion
reactions including the aneutronic proton-boron reaction.
