Lithium Tantalate is pyro-electric, that is, when subjected to heat it generates an internal voltage. The crystal structure of pyro-electric materials is assymmetric giving rise to electrical polarization of the atoms. When heated, the polarization is altered dramatically, setting up strong internal electric fields, which can be very powerful in some pyro-electrics.

If lithium tantalate is heated in a dilute gas to 100C it acquires an internal electric field so powerful that it strips the electrons from the gas molecules that have been able to penetrate beyond the surface of the crystal. Those gas molecules are then accelerated to huge energies by the electric field. The accelerated electrons collide with static nuclei within the crystal generating the X-rays.

If deuterium is used as the gas, and the lithium tantalate crystal is first cooled to -33C then heated to 7C over a period of 4 minutes, the resulting electric field is strong enough to accelerate deuterium nuclei to energies of 100keV, which when they collide with other deuterium atoms that have permeated the surface layer of the crystal, they underwent nuclear fusion, and producing 400 times as many neutrons as the background radiation, i.e. it produced about 300 neutrons per second. This is very small, and any commercial source of neutrons would have to produce 10's of millions per second or more.