Population distributions of metastable state of gadolinium atoms produced by electron beam heating were measured by laser light absorption. The atomic excitation temperature was determined to be 14001600 K from the population distributions. The atomic excitation temperature decreased with increasing evaporation and was much lower than the evaporation surface temperature of 21002400 K which was estimated from, the evaporation rate.
A new Monte Carlo analytical technique is proposed to calculate the pressure distribution in an arbitrary three-dimensional structure. This technique has two features : First, an analytical model composed of complicated three-dimensional components can be built easily by the set theory and coordinate transformations, and second, pressures in the model can be calculated by counting the particles passing through the imaginary walls without interference with the particles. This technique was applied to the calculation of pressure distribution in the JT-60 neutral beam injector (NBI). The analytical results were in good agreement with the experimental ones, and hence the analytical technique was shown to be valid for the calculation of pressure distribution in an arbitrary three-dimensional structure composed of many complicated components.