Simulation of eddy current on the turbo-molecular pump in a magnetic field

Ogiwara, Norio; Kanazawa, Kenichiro; Yanagibashi, Toru

In order to use turbo-molecular pumps (TMPs) in the quasi-static magnetic field often employed in nuclear fusion devices and particle accelerators, we have attempted to establish a standard procedure for determining the influence of magnetic field on TMPs. This time, the computer simulation was carried out to compare with the experimental results reported elsewhere and revise more finely the semi-empirical (semi-infinite conductor) model for the eddy current. As a result, experimental results related to the dependence of the eddy current loss not only on the direction of the magnetic field but also on the revolution frequency of the rotor are confirmed with the simulation.