Photographic Emulsions, Films, and Papers

1972 ◽

Vol 30 ◽

pp. 594-595

Author(s):

Keinosuke Kobayashi

Keyword(s):

High Voltage ◽

Linear Response ◽

Thickness Distribution ◽

Contour Map ◽

Mass Thickness ◽

Voltage Electron ◽

High Voltage Electron ◽

Homogeneous Particle ◽

Photographic Emulsions ◽

Logarithmic Relation

Equidensitometry as developed by E. Lau and W. Krug has been little used in the analysis of ordinary electron photomicrographs, yet its application to the high voltage electron images proves merits of this procedure. Proper sets (families) of equidensities as shown in the next page are able to reveal the contour map of mass thickness distribution in thick noncrystalline specimens. The change in density of the electron micrograph is directly related to the mass thickness of corresponding area in the specimen, because of the linear response of photographic emulsions to electrons and the logarithmic relation between electron opacity and mass thickness of amorphous object.This linearity is verified by equidensitometry of a spherical solid object as shown in Fig. 1a. The object is a large (1 μ) homogeneous particle of polystyrene. Fig. 1b is a composite print of three equidensities of the 1st order prepared from Fig. 1a.

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Factors in Photographic Emulsions for Low Dose Electron Crystallography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s143192760000101x ◽

1980 ◽

Vol 38 ◽

pp. 230-231

Author(s):

T.W. Jeng ◽

W. Chiu

Keyword(s):

Radiation Damage ◽

Low Dose ◽

Damage Effect ◽

Photographic Emulsion ◽

Electron Crystallography ◽

Electron Microscopic ◽

X Ray ◽

Signal Contrast ◽

Diffraction Patterns ◽

Photographic Emulsions

With the advances in preparing biological materials in a thin and highly ordered form, and in maintaining them hydrated under vacuum, electron crystallography has become an important tool for biological structure investigation at high resolution (1,2). However, the electron radiation damage would limit the capability of recording reflections with low intensities in an electron diffraction pattern. It has been demonstrated that the use of a low temperature stage can reduce the radiation damage effect and that one can expose the specimen with a higher dose in order to increase the signal contrast (3). A further improvement can be made by selecting a proper photographic emulsion. The primary factors in evaluating the suitability of photographic emulsion for recording low dose diffraction patterns are speed, fog level, electron response at low electron exposure, linearity, and usable range of exposure. We have compared these factors with three photographic emulsions including Kodak electron microscopic plate (EMP), Industrex AA x-ray film (AA x-ray) and Kodak nuclear track film (NTB3).

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Disintegrations produced in the light elements of nuclear emulsions by 950 MeV protons

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1956.0115 ◽

1956 ◽

Vol 236 (1204) ◽

pp. 104-111 ◽

Cited By ~ 4

Keyword(s):

Potential Barrier ◽

Coulomb Barrier ◽

Light Nucleus ◽

Light Nuclei ◽

Light Elements ◽

Heavy Nuclei ◽

Particle Track ◽

Proton Track ◽

Photographic Emulsions ◽

Mev Protons

Ilford G 5 photographic emulsions have been exposed to 950 MeV protons from the Birmingham synchrotron, and 430 m of proton track searched for nuclear disintegrations. Disintegrations of carbon, nitrogen and oxygen were selected by the potential barrier criterion; the adequacy of this method, which depends on the presence of a short a-particle track indicating the low Coulomb barrier of a disintegrating light nucleus, is discussed. The characteristics of the disintegrations occurring in the light nuclei are described and compared with those for heavy nuclei; most of the observed differences can be explained as features of the complete break-up of a nucleus consisting of a small number of nucleons.

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A study of the nuclear disintegrations produced by 950 MeV protons

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1955.0180 ◽

1955 ◽

Vol 231 (1186) ◽

pp. 368-378 ◽

Cited By ~ 21

Keyword(s):

Simple Model ◽

Excitation Energy ◽

Residual Nucleus ◽

Parent Nucleus ◽

Heavy Nuclei ◽

Substantial Fraction ◽

Photographic Emulsions ◽

Mev Protons

Nuclear disintegrations produced in the heavy nuclei of Ilford G 5 photographic emulsions by 950 MeV protons have been analyzed in detail. The characteristics of the disintegrations observed can be explained in terms of a simple model which assumes that a substantial fraction of the π mesons created is reabsorbed in the parent nucleus and that the energy of these mesons contributes mainly to the excitation energy of the residual nucleus.

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