| 摘要 |
PURPOSE:To reduce energy flowed in plasma and realize long life by forming a small diameter portion on a plasma generating unit of a vacuum tube and generating stable magnetic field parallel with plasma current by flowing return current helically. CONSTITUTION:A small diameter portion 21a is formed on a plasma generating unit of a vacuum tub 21 accommodating a mercury cathode 6 and an anode 2, and a cylindrical return current conductor 22 of two split connected to a cathode terminal 9 is provided around the portion 21a, and a helical type return current conductor 23 connected to the conductor 22 at the connecting point 24 and one end of which is connected to a conductor 25 is provided around the conductor 22 to form ignitron performing switch action. And a stable magnetic field parallel with plasma current is made to be generated on the plasma generating unit by flowing the return current helically. Then, plasma is stabilized and energy flowing into plasma is reduced, and switch characteristic can be improved. |
