  A procedure for loading particle velocities from a relativistic kappa
distribution in particle-in-cell (PIC) and Monte Carlo simulations is
presented. It is based on the rejection method and the beta prime distribution.
The rejection part extends earlier method for the Maxwell-Juttner distribution,
and then the acceptance rate reaches ~95%. Utilizing the generalized beta prime
distributions, we successfully reproduce the relativistic kappa distribution,
including the power-law tail. The derivation of the procedure, mathematical
preparations, comparison with other procedures, and numerical tests are
presented.
