Generation of focused electron beam by pyroelectric and photogalvanic crystals

We have developed a model to explain the phenomena of electron focusing by pyroelectric crystals. The pyroelectric crystals used to compare the experiments with theory were the Fe-doped and undoped LiNbO3. The crystals were either heated from the +z end or illuminated with a laser. Heating the crystals by passing a current through a resistor attached to the +z end produced the pyroelectric effect, a change in polarization in response to a change in temperature. The crystal illumination with a cw solid-state diode-pumped laser (532 nm and 100 mW) produces the photogalvanic current, which creates charges on polar surface of the LiNbO3:Fe. In both cases, the polar ends of the crystal becomes electrically charged and produced self-focusing electron beams that were imaged on a ZnS screen. In addition, we have demonstrated x-ray imaging using the pyroelectric effect