Conceptual D- source exploiting negative surface ionization of deuterons

Under conditions of grazing incidence (theta = 75 to 850) deuterons are specularly reflected from cesiated monochrystals of W, even at energies of a few keV. A fraction of 10 to 45% is charged negatively during the process. These features suggest an improved concept of a D--source in which the extraction of a high quality beam is separated from the formation of D--ions. We shall discuss an experiment designed to test the above ideas at high current densities (250 mA cm-2). The aim is the development of a source delivering a 50 mA cm-2 negative hydrogen beam at 20 kV having a divergence of 60