Principal schemes of laboratory accelerating devices of explosive type, which are applied at Russian Federal Nuclear Center (Arzamas-16) to measure dynamic compressibility of substances under pressures up to 2-3 TPa (20-30 Mbar), are presented in this paper. Three types of such devices are considered.
Devices of the first type are based on deceleration of explosion products against metal screen, where they generate stationary shock wave with amplitude up to 45 GPa (450 kbar) [1].
What the devices of the second type are concerned, pressures in the screen shielded investigated samples are caused by impact of thin metal plates accelerated up to maximum velocity of 6 km/s. As this takes place, pressures in the samples are up to 200 GPa (2 Mbar) [2].
Devices of the third type are semispherical [3], where explosion products of converged detonation wave accelerate steel cover-projectile, which "converges" to the system center. Initiation is carried out in synchronism along all exterior surface of charge. In one of measuring devices maximum velocity of the cover near the center is approximately 23 kin/s, in the beginning of movement its velocity is 6 km/s. impact of such cover against samples causes pressures of 200 GPa -3 TPa correspondingly in them.
Compression parameters of iron, which is reference metal for invesUgation of other substance compressibility, are determined at pressures up to 1.83 TPa with help of these devices. Taking into account measurements of iron compressibility carried out under conditions of underground nuclear explosions, which are shock-wave generators of a sort, shock adiabat of iron is determined at pressures up to l0 TPa. Its interpolation into area of higher pressures determined by theoretical solution is presented in the paper.
Let us consider particular accelerating systems employed at Russian Federal Nuclear Center to measure shock compressiNlity of substances. 1. Devices to provide pressures up to 45 GPa [ 11. Scheme uf such device is depicted in Fig. l.