Fabry–Perot laser interferometry is used to obtain nanosecond time resolved particle velocity histories of the free surfaces of copper, tantalum, or magnesium disks driven by detonating triaminotrinitrobenzene (TATB)-based charges and of the interfaces between detonating TATB and transparent salt crystals. Detonation reaction zone profiles are measured for self-sustaining detonation waves propagating through various thicknesses of LX-17 (92.5&percent; TATB and 7.5&percent; KelF binder) and pure ultrafine particle size TATB. The experimental records are compared to particle velocity histories calculated with the DYNA2D hydrodynamic code using the ignition and growth reactive flow model. The calculations yield excellent agreement with the experimental records for LX-17 using an unreacted von Neumann spike pressure of 33.7 GPa, a reaction rate law which releases 70&percent; of the chemical energy within 100 ns, and the remaining 30&percent; over 300 additional ns, and a reaction product equation of state fit to cylinder test and supracompression data with a Chapman–Jouguet (C–J) pressure of 25 GPa. The late time energy release is attributed to diffusion controlled solid carbon particle formation. Ultrafine TATB, pressed to a lower density(1.80 g/cm3)than LX-17(1.905 g/cm3),exhibits lower unreacted spike and C–J pressures than LX-17 but similar reaction rates. ©1997 American Institute of Physics.