LUMINOSITY OF SHOCK-WAVES IN ACETONITRILE

Acetonitrile is shown to retain its transparency behind the shock fron t at pressures of up to 12.4 GPa and experiences no chemical transform ation (degradation). At pressures in the wave above 17 GPa the tempera tures at the shock front and in the material near the contact surface with window material which retains its transparency extrapolated to th e pressure in the incident wave differ by 500 K. This is accounted for by shielding, on the front side, of radiation issuing from the final state of the degradation products by layers with incomplete conversion . Temperatures measured at the acetonitrile decane interface are close to those calculated assuming that acetonitrile decomposes behind the shock front to form methane and carbon in the form of diamond, The sta te of acetonitrile on the shock Hugoniot below the range it decomposes is assessed.