Fusion ignition of microfission explosions

Abstract

WINTERBERG1 proposed that microexplosions could be caused in very small amounts of fissionable materials such as 233U, 235U, and 239Pu (see also refs 2 and 3). A small critical mass could be created by imploding the fissionable material until it was 200–300 times its normal density. This could be achieved using a high energy, properly shaped laser pulse (of about 1 ns duration). For a chain reaction to begin in the assembled critical mass, however, neutrons must be present to initiate the fission process. For a critical mass of uranium, of 0.34 g, and a hydrodynamic disassembly time of 10−9s, as proposed by Winterberg1, conventional neutron sources will not be adequate to initiate a chain reaction. Initiation of the fission process using neutrons produced from the fusion of a deuterium–tritium (D–T) mixture placed in the core of the fissionable material seems feasible and offers several distinct advantages over conventional neutron sources.