Proton radiography applications with MCNP5.

A modified version of MCNP5 has been developed to treat continuous-energy proton transport. This work is summarised in companion papers by Hughes et al. and Bull et al. (in these proceedings). An intrinsic part of this development effort has involved testing, verification and validation of a capability for simulating proton radiographs. This paper presents the results of calculations simulating various different test objects and the effects of alternative physics models. The significant physics processes include elastic scattering, multiple coulomb scattering, collisional energy-loss and straggling, magnetic fields and attenuation owing to nuclear interactions. Comparisons with experimental data are presented.

Magnetic field tracking with MCNP5.

With the introduction of continuous-energy heavy charged particle transport in MCNP5, the need for tracking charged particles in a magnetic field becomes increasingly important. Two methods for including magnetic field effects on charged particles are included in the proton transport version of the code. The first technique utilises transfer maps produced by the beam dynamics simulation and analysis code COSY INFINITY. This method is fast and accurate; however, its use is limited to void cells only and to ensembles of particles with a fairly small energy spread. The second technique, particle ray tracing, is based on an algorithm adopted from the MARS transport code. This method can be applied to both void and material cells and is valid over a very large range of particle energies. Results from tracking particles in a quadrupole 'identity lens' using the two techniques are compared.