Controversy and Consensus: Nuclear Beta Decay 1911-1934

Carsten Jensen, geboren 1952, wuchs in Marstal auf. Er studierte in Kopenhagen Literaturwissenschaft und arbeitete als Journalist und Kritiker. Sein literarisches Arbeiten begann er Mitte der neunziger Jahre.

To all four of us, Carsten was the best possible friend and colleague. To Finn, he was a fellow student in the history of science for several years at the Niels Bohr Institute; to Relge, he was a welcome resource for personal and intellectual interac tion in an otherwise less than fertile environment for the history of science; Roger was Carsten's friend and advisor, not least in the development of the dissertation on which the present book is based; and as director of the Niels Bohr Archive, Erik was his main advisor in his historical work. Because he was the person closest to Carsten's work on his Ph. D. dissertation on the history of beta decay, on which the present book is based, it is only fitting that Erik stands as single author of the words in Carsten's memory at the very beginning of this book. Before his untimely death shortly after the completion of the Ph. D. disser tation, Carsten had himself plans to develop the dissertation into a book. Being a true perfectionist, he wanted to rework the manuscript substantively, especially with regard to relating it to the broader discussion among historians of science.

1 Prelude: Beta-Spectrum Research in the Pre-Nuclear Years, 1900-1911.- 1.1 Discovery and identification of the beta particle.- 1.2 The first experiments on the velocity distribution of beta particles.- 1.3 Absorption measurements question the inhomogeneity of the beta particles.- 1.4 The Hahn-Meitner vs. Wilson controversy.- 1.5 From unity to complexity: magnetic-deflection experiments, 1910-1911.- 2 The Origin of Beta Rays, and the Growing Complexity of Their Spectrum: The Rutherford Era, 1911-1919.- 2.1 Introduction.- 2.2 Rutherford's 1912 theory, and reactions to it.- 2.3 The beta particle as a nuclear constituent.- 2.4 An extreme complexity of beta line-spectra is brought to light: deflection experiments in the years 1911-1913.- 2.5 Continuity as well as lines: The composite beta spectrum.- 2.6 Rutherford's 1914 theory.- 2.7 The Bohr-Sommerfeld quantum conditions and the beta line-spectrum.- 2.8 Rutherford and the gamma rays.- 3 The Rise of a Controversy: Ellis, Meitner and Smekal Advance Different Beta-Spectrum Theories, 1920-1922.- 3.1 Introduction.- 3.2 Internal conversion, nuclear levels, and Ellis's interpretation of the beta line-spectrum.- 3.3 Analogy between alpha and beta emission, and Meitner's interpretation of the beta line-spectrum.- 3.4 Ellis's response to Meitner's hypothesis, and his interpretation of the continuous beta spectrum.- 3.5 Meitner replies to Ellis, and reveals her view on the continuous beta spectrum.- 3.6 The atom as a unity: Smekal joins the discussion, and is met with a sharp reaction.- 3.7 Two repetitions of the Chadwick experiment lead to contradictory conclusions.- 4 Secondary Effects and Order of Emission: Two Main Questions in the Controversy, 1923-1925.- 4.1 Introduction.- 4.2 Meitner investigates thebeta spectrum of UX1 and takes it as further support for her view.- 4.3 Radiationless transitions: Rosseland suggests an explanation of the emission of primary, and some secondary, beta particles.- 4.4 The nuclear field and the Compton effect: Two possible reasons for the continuous beta spectrum.- 4.5 Ellis and Skinner reinvestigate the beta line-spectra of RaB and C, and serious problems arise.- 4.6 Beta first, gamma second, or is it the other way around?.- 5 The End of the Beginning: The Controversy Enters the Decisive Phase, 1925-1929.- 5.1 Introduction.- 5.2 Ellis adjusts his view on the emission process, but maintains his interpretation of the continuous spectrum.- 5.3 The number of emitted beta particles.- 5.4 Ellis and Wooster's tour de force: A determination of the heating effect of RaE.- 5.5 Continental reactions to Ellis and Wooster's experiment.- 5.6 Some concluding remarks about the controversy.- 6 From Anomaly to Explanation: The Continuous Beta Spectrum, 1929-1934.- 6.1 Introduction.- 6.2 Non-conservation of energy or a new particle? The first phase of the Bohr-Pauli dispute, 1929-1932.- 6.3 Other attempts at explaining the anomalous continuity.- 6.4 The question of upper limits in beta spectra, and the thorium C branching problem.- 6.5 The impact of the miraculous year: The second phase of the Bohr-Pauli dispute, 1932-1933.- 6.6 The two theories of beta decay.- 7 Towards a Theory of Internal Conversion: The Beta Line-Spectrum, 1927-1934.- 7.1 Introduction.- 7.2 Experimental evidence brings about a new view on the origin of gamma rays.- 7.3 The radiation hypothesis proves insufficient to explain internal conversion of gamma rays.- 7.4 A theory of internal conversion is developed.- Summary and Conclusion.- Name Index.