| 摘要 |
PURPOSE:To relieve load heat of an accelerating electrode, which is developed due to reflected primary electrons, which are discharged from a reverse-current damper after colliding with the former damper, by preparing the surface of the former damper, with which reverse-current electrons collide, from a metal member which discharges a small amount of reflected primary electrons. CONSTITUTION:After positive ions are electrostatically drawn out of plasmas, which are developed between a reverse-current electron damper 4 and an accelerating electrode system 7 by means of an accelerating electrode system 7, they are accelerated. At the same time, electrons are secondarily produced in the space between accelerating electrodes 7a, 7b and 7c. Part of these electrons collide with the accelerating electrode 7a. Electrons which pass through the electrode 7a without colliding with it flow in the direction opposite to that of the flow of the former positive ions, and are made to collide with the reverse- current electron damper 4. Since the damper 4 is made of a metal having a small reflected electron gain, such as aluminum, a small amount of reflected primary electrons are discharged from the damper 4 after reverse-current electrons collide with the damper 4. |
