Diffusion of metastable atoms and optovoltaic effect

It was found that metastable atoms diffusing in a parent gas and bombarding a metal electrode, Hill cause an electric charge to build up on the electr ode. Laser resonant pumping of a transition with a metastable lower revel w ill cause depletion of the metastable atom density that, consequently, alte rs the electrode potential. It has been shown that in the case of neon, Is( 5) metastable atoms are predominantly responsible for appearance of the opt ovoltaic (OV) signal that is defined as a potential difference between two electrodes equidistant from the discharge. By the laser induced fluorescenc e method a stationary distribution of metastables, produced by a discharge and diffusing into a neutral gas, has been measured. The results are suppor ted by a model. Dependence of the OV signal on the position of the laser be am between the discharge and one of the electrodes has also been measured a nd a physical model developed.