| 摘要 |
PURPOSE:To raise an exhaust rate with the amount of to-be-spattered matter increased, by installing a control electrode on one side of a cathode and having kinetic energy of an incident ion in the cathode as positive potential distributed to a large region in terms of a ratio of spattering. CONSTITUTION:Most of gaseous molecules which are ionized by an electron group made up at a hollow part 2 of an anode 1 collide with either getter matter 3a or 3b of a cathode 3 and spatter the getter matter. An energy distribution function of an incident ion adopts a value other than zero and takes a shape of being shifted to the higher energy side of that function in a state of almost the same electric discharge action. As a result, an integrand of numbers per unit time of the getter matter of the cathode to be spattered takes a large value than that in case of the conventional triple-pole type ion pump and thereby the amount of the spattered getter matter becomes increased, taking the best effect to increase the exhaust rate of an ion pump. |
