Talk:Electrostatic deflection

Electrostatic deflection is very useful for small deflection angles but is well know to be inferior to magnetic deflection for deflecting a charged particle beam into large angles - say over 10 degrees. Also in electrostatic deflection it has long been the practice to inject the beam midway between the charged deflection plates so as to avoid the fringe fields as much as possible. However it was found by computation methods that deflection aberations would be significantly reduced if the beam were injected offset toward the attracting plate. That way the beam tends to follow equipotentials and the force is normal to the beam direction. Thus offset, all the electrons in the beam are deflected into the same angle. There is an induced astigmatism that is correctable. This deflection idea has been tested and verified. Deflection angles of 50 degrees are possible without measurable deflection aberration. Optimal injection offset is approximately 1/3 of the plate gap toward the deflecting plate. The useful beam diameter is also approximately 1/3 of the gap. See M. Retsky and R. Stein. Testing an electron beam deflection innovation: Initial results. Jour. Vacuum Science and Tech. B 20(6): 2678-2681 Nov/Dec 2002. Also see US patents 6614151, 6232709, and 5825123. —Preceding unsigned comment added by 24.151.69.65 (talk) 19:17, 13 January 2008 (UTC)