Electron-optical imaging system having controllable elements

摘要

The invention is directed to an electron-optical imaging system such as for an electron microscope. The imaging system has magnetic lenses, current and voltage sources corresponding thereto, a computer, a permanent memory and a touch panel. The electron microscope is manually calibrated when first taken into use by a discrete sequence of different operating conditions. Polynomes of the second degree are adapted to the experimentally calibrated parameter values for the lens currents. The computer polynome coefficients are stored in a permanent memory. Operating states are adjustable via the touch panel on the operating console of the electron microscope. These operating states lie between the calibrated operating states. The lens currents necessary for these operating states are computed in the computer based on the function coefficients stored in the memory and are subsequently emitted to the current sources by the computer. The step width in which the operating states are adjustable is preselectable via the keyboard independently of the position of the calibrated operating conditions.