The grain-density of emulsion tracks

Journal Article · Sun Dec 31 23:00:00 EST 1961 · Il Nuovo Cimento

DOI:https://doi.org/10.1007/BF02887195· OSTI ID:4828728

Patrick, J. W.; Barkas, W. H.

Measurements of the true grain density were made using methods on the tracks of electrons, pions, K mesons, protons, SIGMA hyperons, and alpha particles. The curve of grain density vs velocity in K-5 emulsion was obtained. The results found by different objective methods and by different observers agree. Due to the finite density of silver-halide crystals in the emulsion, the grain- density saturates. The nature of the saturation effect was studied. A decomposition of the grain-density into primary and secondary components was made. Even at the minimum of grain density, about 25% of the grains are of secondary origin. Since only the primary grains are affected by the relativistic rise of the grain density, the interpretation of the plateau/minimum grain density ratio is affected. Observations of the grain density in the relativistic region were made, avoiding temperature, fading, and development-difference effects. A rise to the plateau of 18% in the primary grain density was found. This implies a mean excitation potential for AgBr of 442 ev. Indices measuring emulsion quality are suggested.

• Research Organization: University of California, Lawrence Radiation Laboratory, Berkeley, CA (US)
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• DOE Contract Number: W-7405-ENG-48
• NSA Number: NSA-16-020677
• OSTI ID: 4828728
• Report Number(s): UCRL-9692; 0029-6341
• Journal Information: Il Nuovo Cimento, Journal Name: Il Nuovo Cimento Journal Issue: S1 Vol. 23; ISSN 1827-6121
• Country of Publication: United States
• Language: English

Related Subjects

ENGINEERING AND EQUIPMENT