NIELS BOHR COLLECTED WORKS GENERAL EDITOR ERIK RÜDINGER THE NIELS BOHR ARCHIVE, COPENHAGEN VOLUME 8 THE PENETRATION OF CHARGED PARTICLES THROUGH MATTER (1912-1954) EDITED BY JENS THORSEN EUROPEAN SCHOOL, LUXEMBOURG HP 1987 NORTH-HOLLAND AMSTERDAM OXFORD NEW YORK TOKYO
Foreword to Volume 8 Contents Abbreviated Titles of Periodicals Abbreviations Acknowledgements v IX XIV XVII XIX PARTI: THE CLASSICAL THEORY Introduction 3 1 Bohr's First Stay in Manchester (1912) 4 2 Darwin's Theory of the Absorption of a Rays (1912) 5 3 Bohr's First Paper on the Absorption of Charged Particles (1912-1913) 7 4 Bohr's Second Paper on the Absorption of Charged Particles (1915) 13 5 The Problem ofquantized Energy Transfer (1913-1916) 17 6 Experimental Work in Copenhagen (1918-1920) 24 7 Collisions ofthe Second Kind (1921-1922) 27 8 Correspondence Concerning Collision Problems (1921-1922) 28 9 "On the Behaviour of Atoms in Collisions" (1925) 30 I Physical Experiments, Manchester (1912); Facsimile 37 II Moving Electrified Particles [1912]; Unpublished Manuscript 43 Facsimile 46 III On the Theory ofthe Decrease of Velocity ofmoving Electrified Particles on passing through Matter, Phil. Mag. 25(1913) 10-31 47 IV On Absorption ofa and ß Rays; Om Absorption afix- og ß-Straaler (1912); Unpublished Manuscript 73 Translation 90 V On the Decrease in Velocity of a. andß Rays in passing through Matter (1915); Unpublished Manuscript 107 Facsimile 113 VI General Remarks on Absorption of a. and ß Rays (left out of Paper July 1915); Unpublished Manuscript 115 IX
VII Calculation of Decrease of Velocity ofa and ß Rays [1915]; Unpublished Manuscript 119 Facsimile 124 VIII On the Decrease of Velocity of Swiftly Moving Electrified Particles in passing through Matter, Phil. Mag. 30 (1915) 581-612 127 IX Note on Scattering ofa. Rays [1916]; Unpublished Manuscript 161 X Recent Work on Atomic Theory (1916); Nyere Arbejder over Atomteorien; Manuscript 167 Translation 172 Facsimile 177 XI On the Result ofcollisions belween Atomic Systems and Free Electrical Particles [1] (1920); Om Virkningen af Sammenstod mellem Atomsystemer og fri elektriske Partikler; Unpublished Manuscript 181 Translation 188 XII On the Result ofcollisions between A tomic Systems and Free Electrical Particles [2] (1920); Om Virkningen af Sammensted mellem Atomsystemer og fri elektriske Partikler, Det nordiske H.C. 0rsted Mode i Kobenhavn 1920, H.C. 0rsted Komiteen, Copenhagen 1921, pp. 120-121 195 Translation 199 PART II: GENERAL THEORY OF PENETRATION Introduction 203 1 Capture and Loss of Electrons in Atomic Collisions (1925-1926) 203 2 Quantum-mechanical Treatment of Collision Phenomena (1926-1930) 206 3 Treatment of Collision Problems in Copenhagen (1931-1932) 214 4 Work with E.J. Williams on Collision Problems 221 5 Scattering and Stopping of Fission Fragments (1940) 232 6 "The Penetration of Atomic Particles through Matter" (1940-1948) 240 7 Electron Capture and Loss by Heavy Ions (1950-1954) 258 I Atomic Collision Problems and the Recent Discoveries Regarding Nuclear Disintegrations (1932); Unpublished Manuscript 267 Translation 278 II Workwith Williams on Collision Problems (1933-1934); Unpublished Manuscript 287 III NotesfromBohr'sLecluresinPrinceton (1939);hxcetptof NotesTakenbyJohn A. Wheeler 301 IV Scattering and Stopping offission Fragments [1] (1940); Unpublished Manuscript 307 V On the Fragments Ejected in the Disintegration ofthe Uranium Nucleus [1] (1940); Om de ved Urankerners Sonderdeling udslyngede Fragmenter; Outline of Lecture 313 Translation 315 Slides 316 VI On the Fragments Ejected in the Disintegration ofthe Uranium Nucleus [2] (1940); Om de ved Urankernernes Sonderdeling udslyngede Fragmenter; Overs. Dan. Vidensk. Selsk. Virks. Juni 1939-Maj 1940, pp. 49-50 317 Translation 318 X
VII Scattering and Stopping of Fission Fragments [2] (1940); Phys. Rev. 58 (1940) 654-655 319 VIII Velocity-Range Relation for Fission Fragments [1] (with J.K. Boggild, K.J. Brostrom and T. Lauritsen), Phys. Rev. 58 (1940) 839-840 323 IX Velocity-Range Relation for Fission Fragments [2], Phys. Rev. 59 (1941) 270-275 327 X First Outline of Contents of 1948 Paper (1940); Unpublished Manuscript 335 XI Collisions between Charged Particles [1940]; Sammensted mellem elektriske Partikler; Unpublished Manuscript 341 Translation 347 XII Stopping Power and Ionization in Classical and Quantum Theory (1940); Unpublished Manuscript 353 XIII Two Notes Relating to Stopping Power (1940) 357 Contents 360 Translation 361 1 Sandsynlighed for, at en Kerne med Ladning Z x e og Hastighed V fanger en Elektron fra en Kerne Z 2 e; Probability ofcapture ofan Electron from a Nucleus of Charge Z 2 e by a Nucleus of Charge Z x e and Velocity V 362 Translation 363 2 Ioniseringen ved hurtige ladede Partikler; Ionization by Swiftly Moving Charged Particles 365 Translation 366 XIV Early Outlines of Contents of 1948 Paper (1940); Unpublished Manuscript 369 XV The Penetration of Heavy Alomic Particles through Matter (1941); Unpublished Manuscript 373 XVI A Comparison between Thomas' and Kramers' Expressions for the Capture of Electrons (1942); Sammenligning mellem Thomas' og Kramers' Udtrykfor Indfangning qf Elektroner; Unpublished Manuscript 383 Translation 388 XVII Lectures on Scattering and Stopping (1942); Forelasninger over Spredning og Stopning; Excerpt of Lecture Notes 391 Translation 397 XVIII The Penetration of Heavy Atomic Particles through Matter-Introduction (1942); Unpublished Manuscript 403 XIX Note on the Law of Conservation of Energy (1943); Note om Energisatningen; Unpublished Manuscript 409 Translation 412 XX Contents of Paper on Penetration as of September 1943; Unpublished Manuscript 415 XXI Photographs of Blackboards (1948); From a Lecture Given in Princeton in the Spring of 1948 419 XXII The Penetration of Atomic Particles through Matter, Mat.-Fys. Medd. Dan. Vidensk. Selsk. 18, no. 8 (1948) 423 XXIII Discussion Remarks at the 8th Solvay Conference 1948; Les particules elementaires, Rapports et discussions du huitieme Conseil de physique, Bruxelles, 27.9-2.10.1948, R. Stoops, Brüssels 1950 569 XXIV Electron Capture by Swiftly Moving Ions of High Nuclear Charge [1] (1952); Elektronindfangning af hurtigt bevagede Ioner med hoj Kemeladning; Unpublished Manuscript 573 Translation 576 XI
XXV Electron Capture by Swiftly Moving Ions of High Nuclear Charge [2] (1952); Elektronindfangning afhurtigt bevagede Ioner med hoj Kerneladning, Overs. Dan. Vidensk. Selsk. Virks. Juni 1951 - Maj 1952, p. 49 579 Translation 581 XXVI Notes for Bohr's Opposition at N.O. Lassen's Defence ofhis Thesis (1952); Kommentarer til Lassens Disputats; Unpublished Manuscript 583 Translation 586 XXVII Papers by Lassen and Lindhard on Fission Fragments (1952); Papers Presented at the International Physics Conference in Copenhagen, 3-17 June 1952 589 XXVIII Electron Capture and Loss by Heavy Ions Penetrating through Matter (with Jens Lindhard), Mat.-Fys. Medd. Dan. Vidensk. Selsk. 28, no. 7 (1954) 593 APPENDIX E.J. Williams, Application ofordinary Space-Time Concepts in Collision Problems and Relation of Classical Theory to Born 's Approximation, Rev. Mod. Phys. 17 (1945)217-226 627 PART III: SELECTED CORRESPONDENCE (1913-1950) Inlroduction 641 Correspondence Included 642 Correspondents Patrick M.S. Blackett 649 Felix Bloch 650 Max Born 656 William Lawrence Bragg 664 Marie Curie 664 Clive Cuthbertson 665 Adriaan Daniel Fokker 667 Ralph Howard Fowler 677 James Franck 680 Hans Marius Hansen 695 Douglas R. Hartree 698 Werner Heisenberg 699 George H. Henderson 706 George de Hevesy 706 Fritz Kalckar 709 Oskar Klein 711 Martin Knudsen 717 Fritz K. W. Kohlrausch 719 Hendrik Anthony Kramers 726 Willis E. Lamb 739 Niels Ove Lassen 740 Thomas Lauritsen 748 Ernest Marsden 751 Harry Milton Miller 753 NevillF.Mott 754 XII
Carl Wilhelm Oseen 755 Robert L. Platzman 759 Heinrich Rausch von Traubenberg 766 Svein Rosseland 769 Ernest Rutherford 783 Megh Nad Saha 788 Edward Teller 789 John A. Wheeler 790 Evan James Williams 791 INVENTORY OF RELEVANT MANUSCRIPTS IN THE NIELS BOHR ARCHIVE Introduction 817 INDEX xni