  Inelastic and elastic neutron scattering is used to study spin correlations
in the quasi-one dimensional quantum antiferromagnet IPA-CuCl3 in strong
applied magnetic fields. A condensation of magnons and commensurate transverse
long-range ordering is observe at a critical filed $H_c=9.5$ T. The field
dependencies of the energies and polarizations of all magnon branches are
investigated both below and above the transition point. Their dispersion is
measured across the entire 1D Brillouin zone in magnetic fields up to 14 T. The
critical wave vector of magnon spectrum truncation [Masuda et al., Phys. Rev.
Lett. 96, 047210 (2006)] is found to shift from h_c 0.35 at H>H_c. A drastic
reduction of magnon bandwidths in the ordered phase [Garlea et al., Phys. Rev.
Lett. 98, 167202 (2007)] is observed and studied in detail. New features of the
spectrum, presumably related to this bandwidth collapse, are observed just
above the transition field.
