The Effect of Shock-Heated Gaseous Helium and Argon on Pin Shortening

Different signals from pins in shock-heated gaseous helium and argon were observed. Assuming that shock wave in gases was one-dimensional and local equilibrium of thermodynamic was reached during shock loading, the state parameters of these two gases were calculated. It is shown that ionization degree for argon exceed 1% when the velocities of flyers ranged from 3 to 5 km/s, this ionization may cause pins shortening before flyers impact pins. However, helium gas was hardly ionized, in which pins work normally.