Beam Efficiency, Inelastic Scatter, and Radiation Damage in the High‐Voltage Microscope

1972 ◽  
Vol 43 (6) ◽  
pp. 2885-2890 ◽  
Author(s):  
D. F. Parsons
Keyword(s):  
Radiation Damage ◽  
High Voltage ◽  
Inelastic Scatter

Design of Sensitive Photographic Materials for the High-Voltage Electron Microscope

1975 ◽  
Vol 33 ◽  
pp. 156-157
Author(s):  
Murray Vernon King ◽  
Donald F. Parsons
Keyword(s):  
Electron Microscope ◽  
Radiation Damage ◽  
High Voltage ◽  
Radiation Sensitivity ◽  
Fast Electrons ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Biological Studies ◽  
Low Sensitivity

Effective application of the high-voltage electron microscope to a wide variety of biological studies has been restricted by the radiation sensitivity of biological systems. The problem of radiation damage has been recognized as a serious factor influencing the amount of information attainable from biological specimens in electron microscopy at conventional voltages around 100 kV. The problem proves to be even more severe at higher voltages around 1 MV. In this range, the problem is the relatively low sensitivity of the existing recording media, which entails inordinately long exposures that give rise to severe radiation damage. This low sensitivity arises from the small linear energy transfer for fast electrons. Few developable grains are created in the emulsion per electron, while most of the energy of the electrons is wasted in the film base.

Recent U.S. Steel Developments in High Voltage Microscopy

1969 ◽  
Vol 27 ◽  
pp. 110-111
Author(s):  
R.M. Fisher ◽  
L.E. Thomas ◽  
J.S. Lally
Keyword(s):  
Radiation Damage ◽  
Electron Micrographs ◽  
High Voltage ◽  
Image Contrast ◽  
General Interest ◽  
Medical Applications ◽  
Electron Radiation ◽  
Considerable Effort ◽  
Voltage Electron ◽  
Characteristic Features

Since its inauguration, the U.S.S. MVEM has been applied to fundamental studies of the nature of electron radiation damage and the mechanisms of strengthening, precipitation and recrystallization as well as industrial and bio-medical applications. In addition, considerable effort has been expended in optimizing the performance of the microscope and in analyzing the characteristic features of image contrast in high voltage electron micrographs. A brief review of the salient features of these studies of general interest to electron microscopists will be presented.

Detection efficiency and estimation of the performance of high voltage STEM

1978 ◽  
Vol 36 (1) ◽  
pp. 84-85
Author(s):  
A. Ishikawa ◽  
C. Morita ◽  
M. Hibino ◽  
S. Maruse
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Radiation Damage ◽  
High Voltage ◽  
Detection Efficiency ◽  
Beam Current ◽  
High Energy ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Transmission Electron

One of the problems which are met in conventional transmission electron microscopy (CTEM) at high voltages is the reduction of the sensitivity of photographic films for high energy electron beams, resulting in the necessity of using high beam current. This cancels out an advantage of high voltage electron microscopy which is otherwise expected from the reduction of the inelastic scattering in the specimen, that is the reduced radiation damage of the specimen during observations. However, it is expected that the efficiency of the detector of scanning transmission electron microscopy (STEM) can be superior to that of CTEM, since the divergence of the electron beam in the detecting material does not affect the quality of the image. In addition to observation with less radiation damage, high voltage STEM with high detection efficiency is very attractive for observations of weak contrast objects since the enhancement of the contrast (which is an important advantage of STEM) is easily realized electrically.

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