Pyroelectric fusion

Pyroelectric fusion refers to the technique of using pyroelectric crystals to generate high strength electrostatic fields to accelerate deuterium ions (tritium might also be used someday) into a metal hydride target also containing deuterium (or tritium) with sufficient kinetic energy to cause these ions to undergo nuclear fusion. It was reported in April 2005 by a team at UCLA. The scientists used a pyroelectric crystal heated from −34 to 7 °C (−29 to 45 °F), combined with a tungsten needle to produce an electric field of about 25 gigavolts per meter to ionize and accelerate deuterium nuclei into an erbium deuteride target. Though the energy of the deuterium ions generated by the crystal has not been directly measured, the authors used 100 keV (a temperature of about 109 K) as an estimate in their modeling. At these energy levels, two deuterium nuclei can fuse to produce a helium-3 nucleus, a 2.45 MeV neutron and bremsstrahlung. Although it makes a useful neutron generator, the apparatus is not intended for power generation since it requires far more energy than it produces.

History

The process of light ion acceleration using electrostatic fields and deuterium ions to produce fusion in solid deuterated targets was first demonstrated by Cockcroft and Walton in 1932 (see Cockcroft–Walton generator). That process is used in miniaturized versions of their original accelerator, in the form of small sealed tube neutron generators, for petroleum exploration.

The process of pyroelectricity has been known from ancient times. The first use of a pyroelectric field to accelerate deuterons was in a 1997 experiment conducted by Drs. V.D. Dougar Jabon, G.V. Fedorovich, and N.V. Samsonenko.