Characterization of degraded hydrogen dissociator envelopes by AES

The performance of hydrogen dissociators used in atomic clocks is known to degrade after prolonged operation, requiring large increases in rf power to maintain a constant output of atomic hydrogen. Auger electron spectroscopy (AES) has been used to characterize the inner surfaces of Pyrex dissociator envelopes. Prolonged operation of the dissociators leads to buildup of a dark film incorporating large quantities of carbon in its amorphous and carbide forms and smaller amounts of nitrogen. Possible mechanisms by which the film could interfere with the operation of the dissociator are given which involve its electrical conductivity and its role as a catalyst in the recombination of atomic hydrogen.