Monte Carlo simulations of the beam effect for the emitted molecules from the rotating disks

Ogiwara, Norio

The angular distribution of molecules emitted from rotating disks with a small gap was simulated using the Monte Carlo method. As the molecules have a circumferential velocity (: distance from the rotating axis and : angular velocity), when they leave the surfaces of the rotating disks, they tend to be emitted toward the tangent lines of the rims of the disks. When the disks rotate with a velocity ratio / (: radius of the disk and : mean velocity of the molecules) of 3.8, three quarters of the outgoing molecules gather within an angle of 0.4 radians from the tangent line. The angular distribution is related to the altitude almost independent of the revolution frequency with a value of less than 2, where the rotating vector is specified to be oriented to zenith.