Il Nuovo Cimento (1955-1965)

, Volume 4, Supplement 2, pp 447–447 | Cite as

Zur Massenbestimmung an geladenen Teilchen in kernphotographischen Emulsionen mittels der Methode der variablen Zellen

  • B. Roederer
Sezione A: Particelle pesanti instabili


The method of constant sagitta using the cell-size tables calculated byFay, Gottstein andHain was applied for scattering measurements on 10 identified flat protons and 12 π-mesons in the region of short ranges (0/5 000 μm). Applying usual noise elimination methods, a systematic deviation from the theoretically expected values ofD0 was observed in the case of protons. Diverse sources for noise or systematic errors were investigated. Distortion was found to be insignificant. The falsifications on the results yielded by: i) the error in reading the-cell length; ii) the wrong alignment of the track parallel to the stage movement, although significant, are not sufficient to explain fully the systematic deviation. It is found, however, that the usual way of working out second differences for the double cell size from these measured in the basic cells is not unrestrictedly applicable for the constant sagitta method because adjoining cells are frequently not of equal size. It is suggested, that noise elimination on short tracks (up to ∼ 5 mm) should either be done between two different cell schemes, i.e. by measuring each particle twice, e.g. once in the π-“ scheme and once in theP0.5 scheme; or by applying appropriate corrections in the conventional noise-elimination method. The magnitude of these corrections will then depend on the alignment and length of the track, the mass of the particle and the scheme used. By measuring each particle in two different schemes, we obtain a very good accordance with the values expected by the formula
$$D_0 = 0.5 \cdot (M_{scheme} /M_{particle} )^{0.43} $$
without any correction to the scattering constant assumed by Fayet al. The calculated noise-level is shown to increase rapidly for double and quadruple cell-size.

Copyright information

© Società Italiana di Fisica 1956

Authors and Affiliations

  • B. Roederer
    • 1
  1. 1.Max-Planck-Institut für PhysikGöttingen

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