| 摘要 |
894,569. Electron miscroscopes. TESLA, NARODNI PODNIK. April 24, 1959 [April 24, 1958], No. 14052/59. Class 39 (1). Astigmatism in the objective lens 1, 2 of an electron microscope is corrected by a 4-pole stigmator 3 which is disposed outside the vacuum space and which is mechanically displaceable in a plane perpendicular to the axis of the lens. The stigmator is excited by field windings 4 through which adjustable direct current is passed. An alternating current may also be passed to enable centering of the field of the system. The stigmator is also mechanically rotatable. The stigmator may be disposed between the pole-pieces of the objective. |
