Patent ID: 7872241
Filing Date: 2011-01-18
Classification: H01J

Abstract:
1. An electron beam production and control assembly, comprising: a vacuum chamber having opposite rearward and forward ends; a beam source located at the rearward end of the vacuum chamber, the beam source producing an electron beam that accumulates ions while the beam is produced, the beam source directing the beam along a path towards the forward end of the chamber; a target located at the forward end of the chamber, the target having an active section and an inactive section, the active section generating x-rays that are directed through a scanner field when the beam impinges on the x-ray producing section; and a focusing unit positioned along the chamber at a location intermediate the rearward end and the forward end, the focusing unit directing the beam towards the target in a converging manner to impinge on the target, the focusing unit sweeping the beam along a scanning path over the active section of the target, the focusing unit moving the beam to a retrace path on the inactive section of the target to maintain ion accumulation in the beam between sweeps over the active section.