Dynamic compressibility of carbamide at low pressures

The shock adiabats of pressed carbamide samples with a density of $1.29$ g/cm$^3$ and carbamide samples with a bulk density of $0.78$ g/cm$^3$ were studied at pressures of $1$–$14$ GPa using an electromagnetic method. In the coordinates $D$ and $U$, the shock adiabat of pressed carbamide is linear and the shock adiabat of carbamide of bulk density at a pressure of $\approx2.4$ GPa is represented as two linear segments: $D=2U$ at $0.6<U <1.3$ km/sec and $D=0.6+1.55U$ at $1.3<U<2.8$ km/sec. The possibility of a phase transition in carbamide under shock compression is discussed.