I. Introduction
The ion stripping method is commonly used for ion beam extraction from a cyclotron [1]–[4]. When passing through a thin foil an ion is deprived of some of its electrons. An ion with a negative charge becomes positively charged after the foil and thus changes the direction of its rotation. The specific charge of a positive ion is increased by the foil and consequently the ion rotation radius is decreased. Both effects are successfully used for beam extraction; however, the extraction of the ions accelerated as positive is more complex due to the loop the beam executes after the foil and before it leaves the cyclotron [5].