The ejection of particles with energy up to 20MeV u(-1) was reported previously from laser-induced processes in ultra-dense deuterium D(0). Studies of the kinetics of particle formation and decay, and of particle penetration through thick plates are now reported. Magnetic deflection is used to remove charged particles like electrons formed at the target. The signals at a collector in the beam at 0.9m distance and a shadowed loop collector behind a 1.5-4.5mm thick steel plate at 0.6m are compared. The signal at the distant collector matches an intermediate particle B in a decay chain A -> B -> C with formation and decay time constants of 5-15 ns. The signal at the loop collector is delayed relative to the more distant collector, thus showing a delay of the particles penetrating through the steel plate. The signal at this collector is due to pair production with charge cancellation. Compton electrons from gamma radiation are observed at peak current densities of 1mA cm(-2) at the distant collector.