sentences:  This is far more efficient than the shock wave, which becomes less important.In HiPER, the compression provided by the driver is "good", but not nearly that created by larger devices like NIF; HiPER's driver is about 200 kJ and produces densities of about 300 g/cm3.That's about one-third that of NIF, and about the same as generated by the earlier NOVA laser of the 1980s.