Paper Title
MgO Photocathode for DC Vacuum-Microdiodes Tunable THZ Sources

Abstract
MgO, referred as a dielectric material has been proved experimentally to be a potential candidate as a cold photoemitter of futuristic DC Vacuum- microdiodes, which are to be employed as THz sources by showing photoemission in femto-ampere range without using any current amplifier, axial magnet field orFarady cup.For the empirical analysis, a commercialMgOsample with dimensions of 10×10×0.5mm, grown withorientation of <100> and polished as 1SP has shown a photocurrent which is measuredby using Keithly 2400source meter and 617 electrometer and is of the order of femto-amperes.For photoemission, an ultraviolet LASERemitting at a wavelength range of 325nm- 442nm (3.81eV-2.8eV, 100mW)is used in continuous wave mode as a photon injector. The photo-emitter is operated below its ablation limit(≤0.03W/mm2) and anelectric field strength is changed from 0.06MV/m to 0.12MW/m. The empirical results showed an excellent agreement with the theoretically values and trends. Therefore, the selection of an MgO photocathode for making THz, DC Vacuum devices and systems promise a cost effective and robust approach for their possible future applications in the fields of sensing and pharmaceuticals. Keywords - Photodetector, Continuous wave, Vacuum-microdiodes, THz sources.