Neutron production with a pyroelectric double-crystal assembly without nano-tip

Abstract

Two cylindrical LiTaO3 crystals facing each other's deuterated circular face were exposed to deuterium gas at an ambient pressure of a few mTorr. With a distance of about 4cm between the z+ and z− cut crystal faces, neutrons were produced via the 2H(d,n)3He fusion reaction upon the heating and cooling of the crystals. The 2.5MeV neutrons were detected with organic liquid scintillation detectors equipped with neutron-gamma pulse-shape discrimination electronics to reject pulses generated by the intense X-ray flux. During the cooling phase of naked crystals, deuterium ion-beam (D2+) energies of up to 400keV were obtained as deduced from the associated electron bremsstrahlung end-point energy. The highest electron-beam energy observed during the heating phase was 360keV. With a layer of deuterated polyethylene evaporated on the front face of the crystals, the maximal energies were about 10% lower. In contrast to earlier studies, an electric-field enhancing nano-tip was not employed. Neutron yields up to 500 per thermal cycle were observed, resulting in a total neutron production yield of about 1.6×104 neutrons per thermal cycle. Our approach has the potential of being substantially improved by reducing the frequency of the discharges we are currently experiencing with our geometry, which was not designed for the unprecedented high potentials produced in the presentwork.