An experiment using field emission microscopy has been performed to investigate the kinetics of Pd adlayer on W surface, such as diffusion, thermal and field desorption processes, and coadsorption of hydrogen and palladium on W surface. The work function upon Pd adsorption on W surface is φ=5.0eV at maximum. When θPd=2.0, for the coverage of Pd there are two states of Pd adlayer on W surface, the weakely bound state that disappears at T=1100_??_1200 K and the more stably bound state that desorbs at T=1500_??_1700 K. Field emission current variation in the field desorption process of Pd adlayer on W surface can be divided into 3 stages: 1) the desorption of the overlayer, 2) the most stable adsorption state and finally, 3) the desorption of the monolayer, When the θPd_??_1.0, the field emission current varies strongly upon the exposure to hydrogen. However, influence is observed at θpd_??_2.0.
Velocity distribution of an atomic beam in a cesium beam frequency standard is analyzed. A simplified numerical calculation method, in which the Ramsey resonance curve is analyzed, is developed to determine simultaneously the velocity distribution function and the nonlinear power parameter by successive approximation. In an experimental method for direct mea-surement of velocity distribution in which the pulse excitation method is used, an automatic measurement system is assembled by applying the technique which uses microwave pulses in the alternate reversed phase. Measurements of the velocity distribution in a commercial beam tube by these methods agree sufficiently with each other. From the results of these analyses, it is expected that the second order Doppler shift can be evaluated within an error of one part in 1014 in the cesium beam frequency standard. The application of the numerical analysis method to the laboratory type cesium beam tube is also described.