Chapter 2.6, Problem 1TQ

Summary Introduction

To review:

The rotation of an image due to magnification in electron microscopy.

Introduction:

Electron microscopy utilizes a beam of electrons instead of a light source. This beam is generated by the formation of high voltage from a magnet that serves as the lens. There are various forms of electron microscopy that are different in several aspects and hence, their resolution powers and effective areas may also vary.

Electron microscopy utilizes an electron beam from an electron source that is projected onto the specimen to be studied. The electron source could be a tungsten filament and the flow of electrons is generated by a high flow of electrons due to the generation of a high voltage in the source. This is accomplished by a magnetic field. The creation of magnetic field focuses on the flow of electrons analogous to the light flowing from a source in a normal microscope.

The magnetic field is thus evident in aligning the electrons as a beam. The beam of electrons spirals as soon as it enters the field because of the influence of the magnetic field lines. This spiral motion of the beam increases or decreases with the magnetic field. The magnetic field fluctuates according to the magnification. Alteration in the spiral motion of the electron beam results in the rotation of the image.