Higher precision in nuclear spectroscopy

NOV 01, 1952

Jesse W. M. DuMond

For nearly six years there has been in existence at the California Institute of Technology a program of research work directed at increasing the precision of all measurements in nuclear spectroscopy and especially the precision with which nuclear energy levels may be determined. This trend toward higher precision of measurement is to be observed at present in nearly every area of nuclear physics (except possibly in the still new very high energy field) for it is generally realized that, while much primary qualitative information has been acquired, a real understanding and interpretation of the problems of nuclear structure and the internal mechanics of nuclei must wait for a sufficient fund of accurate and reliable quantitative numerical data to furnish a foundation for theory to build upon.

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References

1. A. C. G. Mitchell, Rev. Mod. Phys. 22, 36 (1950).https://doi.org/RMPHAT
2. Arne Hedgran, “Precision Measurements of Nuclear Gamma Radiation by Techniques of β‐Ray Spectroscopy,” Ark. Fysik, Vol. 5, No. 1, Part I, p. 2 (1952).
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6. Jesse W. M. DuMond, Rev. Sci. Instr. 18, 626 (1947); https://doi.org/RSINAK
Jesse W. M. DuMond, Rev. Sci. Instr. 18, 617 (1947). Many improvements and modifications have been made in the instrument since the publication of this paper, notable among which is the development of a scintillation crystal detector to replace the original multicellular G‐M counter which was used at first, and the perfecting of a completely automatic robot system for making the wavelength settings and recording the results in printed form on a paper strip.https://doi.org/RSINAK , Rev. Sci. Instrum.
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10. The adjustment referred to is that of DuMond and Cohen, Rev. Mod. Phys. 20, 82 (1748). The values obtained at that time have been revised in more recent adjustments using recent atomic beam and microwave data to a state of still higher accuracy but the changes make no material difference in the present argument.
For the most recent review of the subject see DuMond and Cohen, American Scientist 40, 447 (1952).https://doi.org/AMSCAC
11. A. Hedgran and D. A. Lind, Phys. Rev. 82, 126 (1951).https://doi.org/PHRVAO
12. Jesse W. M. DuMond and E. Richard Cohen, “A Least‐Squares Adjustment of the Atomic Constants as of December 1950.” A Report to the National Research Council Committee on Constants and Conversion Factors of Physics.
13. A table giving these results will be mailed upon request to interested physicists. A paper describing this research work with interpretations of some of the decay schemes is now in the hands of the editors of the Physical Review.

More about the authors

Jesse W. M. DuMond, California Institute of Technology, Pasadena.