The Penetration Of Charged Particles Through Matter (1912 - 1954) (niels Bohr - Collected Works)

Bohr's first acquaintance with the subject of penetration of charged particles through matter was as early as in 1912 when he treated the absorption of &agr; and &bgr; rays on the basis of Rutherford's atomic model. From then on he kept a lifelong interest in the subject, often using it as an important test of the methods of atomic mechanics. His last paper on penetration, written together with Jens Lindhard, dealt with electron capture and loss and was published in 1954. Part I of this volume follows Bohr's work on penetration theory based on classical mechanics. Part II deals with the general theory of penetration, taking quantum-mechanical considerations into account. Content: Edited by Page iii Copyright page Page iv Foreword to Volume 8 Pages v-vii Jens Thorsen Abbreviated Titles of Periodicals Pages xiv-xvi Abbreviations Page xvii Acknowledgements Page xix Introduction Pages 3-36 Jens Thorsen I. Physical Experiments, Manchester: Excerpt from Bohr's Laboratory Notebook 1912 Facsimile Pages 37,39-41 II. Moving Electrified Particles: Unpublished Manuscript [1912] Text and Facsimile Pages 43-45,45a III. On the Theory of the Decrease of Velocity of Moving Electrified Particles on Passing Through Matter: Phil. Mag. 25 (1913) 10–31 Pages 47,49-71 IV. On Absorption of α and β Rays: Om Absorption af α- og β-Straaler Pages 73-106 V. On the Decrease in Velocity of α and β Rays in Passing Through Matter Pages 107-114 VI. General Remarks on Absorption of α and β Rays (Left out of Paper July 1915): Unpublished Manuscript Pages 115-118 VII. Calculation of Decrease of Velocity of α and β Rays: Unpublished Manuscript Pages 119-125 VIII. On the Decrease of Velocity of Swiftly Moving Electrified Particles in Passing Through Matter Pages 127-160 IX. Note on Scattering of α Rays: Unpublished Manuscript [1916] Pages 161-165 X. Recent Work on Atomic Theory: Nyere Arbejder Over Atomteorien Pages 167-179 XI. On the Result of Collisions Between Atomic Systems and Free Electrical Particles [1]: Om Virkningen af Sammenstød Mellem Atomsystemer og Fri Elektriske Partikler Pages 181-193 XII. On the Result of Collisions Between Atomic Systems and Free Electrical Particles [2]: Om Virkningen af Sammenstød Mellem Atomsystemer Og Fri Elektriske Partikler Pages 195-200 Introduction Pages 203-265 Jens Thorsen I. Atomic Collision Problems and the Recent Discoveries Regarding Nuclear Disintegrations: Unpublished Manuscript Pages 267-286 II. Work with Williams on Collision Problems: Unpublished Manuscript 1933–1934 Pages 287-300 III. Notes from Bohr's Lectures in Princeton Pages 301-306 IV. Scattering and Stopping of Fission Fragments [1]: Unpublished Manuscript Pages 307-312 V. On the Fragments Ejected in the Disintegration of the Uranium Nucleus [1]: Om de ved Urankerners Sønderdeling Udslyngede Fragmenter Pages 313-316 VI. On the Fragments Ejected in the Disintegration of the Uranium Nucleus [2]: Om de ved Urankernernes Sønderdeling Udslyngede Fragmenter Pages 317-318 VII. Scattering and Stopping of Fission Fragments [2] Pages 319-321 VIII. Velocity–Range Relation for Fission Fragments [1] Pages 323,325-326 IX. Velocity–Range Relation for Fission Fragments [2] Pages 327-333 X. First Outline of Contents of 1948 Paper: Unpublished Manuscript Pages 335-340 XI. Collisions Between Charged Particles: Sammenstød Mellem Elektriske Partikler Pages 341-352 XII. Stopping Power and Ionization in Classical and Quantum Theory: Unpublished Manuscript Pages 353-356 XIII. Two Notes Relating to Stopping Power: Unpublished Manuscripts Pages 357-368 XIV. Early Outlines of Contents of 1948 Paper: Unpublished Manuscript from Folder Penetration November 1940 Pages 369-372 XV. The Penetration of Heavy Atomic Particles Through Matter: Unpublished Manuscript from Folder Penetration [February 1941] Pages 373-382 XVI. A Comparison Between Thomas' and Kramers' Expressions for the Capture of Electrons: Sammenligning Mellem Thomas' og Kramers' Udtryk for Indfangning af Elektroner Pages 383-390 XVII. Lectures on Scattering and Stopping: Excerpt of Manuscript Pages 391-401 XVIII. The Penetration of Heavy Atomic Particles Through Matter—Introduction: Unpublished Manuscript from Folder Penetration Pages 403-408 XIX. Note on the Law of Conservation of Energy: Note om Energisætningen Pages 409-413 XX. Contents of Paper on Penetration as of September 1943: Unpublished Manuscript from Folder Penetration Pages 415-418 XXI. Photographs of Blackboards: From a Lecture Given in Princeton in the Spring of 1948 Pages 419-422 XXII. The Penetration of Atomic Particles Through Matter Pages 423-568 XXIII. Discussion Remarks at the 8th Solvay Conference 1948 Pages 569-572 XXIV. Electron Capture by Swiftly Moving Ions of High Nuclear Charge [1]: Elektronindfangning af Hurtigt Bevægede Ioner Med Høj Kerneladning Pages 573-577 XXV. Electron Capture by Swiftly Moving Ions of High Nuclear Charge [2]: Elektronindfangning af Hurtigt Bevægede Ioner Med Høj Kerneladning Pages 579-581 XXVI. Notes for Bohr's Opposition at N.O. Lassen's Defence of His Thesis: Unpublished Manuscript Pages 583-588 XXVII. Papers by Lassen and Lindhard on Fission Fragments Pages 589-592 XXVIII. Electron Capture and Loss by Heavy Ions Penetrating through Matter: (With Jens Lindhard) Pages 593-625 Appendix Pages 627-638 Introduction Page 641 Correspondence Included Pages 642-813 Introduction Pages 817,818-824 Index Pages 825,827-838 Bohr's first acquaintance with the subject of penetration of charged particles through matter was as early as in 1912 when he treated the absorption of &agr; and &bgr; rays on the basis of Rutherford's atomic model. From then on he kept a lifelong interest in the subject, often using it as an important test of the methods of atomic mechanics. His last paper on penetration, written together with Jens Lindhard, dealt with electron capture and loss and was published in 1954.

Part I of this volume follows Bohr's work on penetration theory based on classical mechanics. Part II deals with the general theory of penetration, taking quantum-mechanical considerations into account.

The phenomena of scattering and stopping of charged particles passing through matter have played a very significant role in the development of atomic and quantum physics, because an understanding of these effects requires a knowledge of atomic structure and dynamics.