Patent ID: 7019316

Claim:
A high-energy ion implanter comprising: a tandem accelerator including an accelerating tank defining an accelerating space, a low-energy accelerator that accelerates negative ions at a first energy, a stripper in which a charge exchanging gas removes electrons from negative ions so as to convert the negative ions into positive ions, a high-energy accelerator that accelerates the positive ions at a second energy, a turbo pump connected to the stripper so as to circulate the charge exchanging gas through the stripper, and a dynamo connected to the turbo pump so as to drive the turbo pump, said low-energy accelerator, stripper and high-energy accelerator being disposed in series in said accelerating space; a low-energy box disposed at a front end of the tandem accelerator, and through which the negative ions are supplied to the low-energy accelerator; a high-energy box disposed at the rear end of the tandem accelerator so as to receive the positive ions from the high-energy accelerator; gas sensors disposed, respectively, in the low-energy box and the high-energy box, and operative to measure the amount of gas in the low-energy box and the high-energy box, and to detect the constituents of the gas in the low-energy box and the high-energy box, respectively; and a controller electrically coupled to the gas sensors so as to receive therefrom data indicative of the amounts and constituents of gas in said low-energy and high-energy boxes, and operative to compare said data with standard data on the charge exchanging gas.