Phase: RAMI3BRF in the principal plane for multiple-scattered (two or more scattering events) radiation
brfpp_mlt for HET01_DIS_UNI_RED_20 testcase.
brfpp_mlt for HET01_DIS_UNI_RED_50 testcase.
brfpp_mlt for HET01_DIS_UNI_NIR_20 testcase.
brfpp_mlt for HET01_DIS_UNI_NIR_50 testcase.