1. A method for controlling an ion beam, the method comprising:
imparting an ion beam from an ion beam source into an end of a cylindrical tube, the ion beam having an original cross sectional
deflecting the ion beam to strike an interior wall of the tube at an angle, thereby creating an impact area of the ion beam
on the interior wall that is greater than the original cross sectional area; and
rotating the deflected ion beam around a circumference of the interior wall of the tube, thereby increasing the impact area
of the ion beam on the interior wall;
wherein a beam power of the ion beam is absorbed by the increased impact area on the interior wall.