An academic approach

In the early days of the COVID-19 pandemic, initially working from the isolation of his home office, Los Alamos National Laboratory scientist Mark Chadwick led an effort to bring together colleagues to document new research  on Manhattan Project experiments. The resulting collection of 46 papers was published in the Laboratory’s Weapons Review Letters classified journal; 23 of those papers were published as a special open-access issue of the American Nuclear Society’s Nuclear Technology journal.

Five years later, Chadwick launched a similar initiative with a different focus. This time, he invited colleagues to examine early fusion research at Los Alamos, particularly its role in the development of thermonuclear weapons. That effort produced 35 papers published in the Weapons Review Letters. Fourteen of those articles were unclassified and subsequently appeared in Volume 80 (2024) of the American Nuclear Society’s Fusion Science and Technology journal.

“Much of the nuclear fusion technical history presented herein has not been previously reported,” Chadwick and his coauthor, Cameron Reed, write in their introduction. “The papers describe aspects of fusion science from this period, including shock hydrodynamics, electron-radiation coupling, and nuclear physics, such as the discovery of resonances in both the DT [deuterium-tritium] cross section and the lithium tritium-breeding cross section.”

According to Chadwick, the response to both journal issues has been overwhelmingly positive. In addition to presenting new findings, readers have appreciated the opportunity to revisit the history of early fusion research. “While the papers in this issue are testament to the vigorous level of fusion research carried out during and after the Manhattan Project,” Chadwick wrote, “the subsequent course of events makes it easy to forget just how speculative the idea of a fission bomb was in the fall of 1941—let alone a fusion device.” ★

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The following papers were published in Los Alamos National Laboratory’s Weapons Review Letters journal. Individuals with permission and security clearances may access the WRL papers by emailing editor Craig Carmer (csc@lanl.gov). Many of these papers were also published in Fusion Science and Technology.

1. (U) The Evolution of Early Soviet Thermonuclear Bomb Designs; Stephen A. Becker
2. (U) Computing the Early Thermonuclear Devices; B. J. Archer
3. (U) Importance of the 5He (D+T) 3/2+ Resonance to Performance; C. R. Bates and Mark B. Chadwick
4. The Earlier DT Fusion Discoveries, 1938–1955; M. B. Chadwick, G. M. Hale, M. W. Paris. J. P. Lestone, C. Bates, J. B. Wilhelmy, S. A. Andrews, W. Tornow, and S. W. Finch
5. (U) The Konopinski–Teller–Ulam Invention; J. I. Katz
6. (U) The Invention of the Nemo; J. I. Katz
7. (U) From Alarm Clock to the Modern Secondary; J. I. Katz
8. (U) Harold Agnew’s 2001 Speech at Los Alamos; Karen Larue and Daniel Alcazar
9. Richtmyer on Shocks: “Proposed Numerical Method for Calculation of Shocks,” An Annotation of LA-671; L. G. Margolin and K. L. Van Buren
10. (U) The Teller–Ulam Innovation: A Survey of Relative Credit Given; M.B. Chadwick
11. The First Calculation of Comptonization; J. I. Katz
12. (U) Commentary on Oppenheimer’s “Memorandum on Nuclear Reactions” about H-Bomb Feasibility Following the 1942 Berkeley Conference; M. B. Chadwick and Jonathan Katz
13. DT Fusion Through the 5He (D+T) 3/2+ “Bretscher State” Accounts for  25% of Our Existence via Nucleosynthesis and the Possibility of Nuclear Fusion; M. B. Chadwick, M. W. Paris, and B. M. Haines
14. (U) Oppenheimer’s Berkeley 1942 Meeting: Feasibility of an A-Bomb as Communicated by Oppenheimer to Peierls in November 1942; Richard Moore and M. B. Chadwick
15. (U) Klaus Fuchs’s Handwritten Notes on Fermi’s 1945 Super Lectures; Richard Moore and M. B. Chadwick
16. Early Thermonuclear Cross Section Advances 1942–1953 & Comparison to Today’s ENDF Data; M. B. Chadwick, M. W. Paris, G. M. Hale, J. P. Lestone, S. Alhumaida, J. B. Wilhelmy, and N. A. Gibson
17. The Serendipitous Discovery of the New Elements Einsteinium and Fermium from the Debris of the Mike Nuclear Test; Stephen Allan Becker
18. Ruhlig’s 1938 Observation of the A=3 Ions with Deuterium: An Analysis of Secondary Reactions Following dd Fusion in a Heavy Phosphoric Target; J. P. Lestone, C. R. Bates, M. B. Chadwick, and M. W. Paris
19. (U) The Koon Event: Hitting Rock Bottom; Tom Ramos
20. Thoughts on the H-Bomb Decision, Oppenheimer’s Loyalty/ Security Hearing, and the Vacation of the AEC Decision; Thom Mason
21. (U) Updated Calculations of Castle Union; Noah Braun
22. (U) Radiative Opacity and the Development of the H-Bomb; David Kilcrease
23. (U) “Turning on the Light”: The Development of the First UK Staged Thermonuclear Warheads; Richard Moore
24. (U) Origins of Lithium Hydride in US Thermonuclear Weapons, Part I: Lithium Hydride Material and Fabrication Efforts at Design Agencies; C. Haertling
25. (U) Origins of Lithium Hydride in US Thermonuclear Weapons, Part II: Production Efforts at the Oak Ridge Y-12 Plant; C. Haertling and S. Brown
26. Some of the History Surrounding the Oliphant et al. Discovery of dd Fusion and an Inference of the d(d,p)t Cross Section from this 1934 Paper; J. P. Lestone
27. (U) Lithium-7 Cross Sections and the Puzzle of the Castle Bravo Prediction; C. R. Bates, K. A. Eriksen, N. A. Gibson, M. P. Bernardin, and M. B. Chadwick
28. (U) An Investigation of the Bravo Surprise; P. W. Rambo
29. Lithium Neutron Cross Sections During the Manhattan Project and the Quest for the H-Bomb; C. R. Bates and M. B. Chadwick
30. (U) Sorting Out the 1945–1946 Super Patent Idea: Who Did What & and Errors in the Open Literature Regarding Claims of Fuchs’s Inventions; M.B. Chadwick
31. Did Fermi First Suggest Using Radiation to Ignite Thermonuclear Fuel?; M. B. Chadwick
32. (U) Teller’s Testament: How the Idea of the Implosion Emerged and History of the H-Bomb Invention; M.B. Chadwick
33. The Simple Element and Ivy Mike; Jonathan E. Morgan
34. The H-Bomb Controversy (U) [republish LA-14069-H in special issue]; Conrad L. Longmire
35. Origins of the Early H-Bomb (U) [republish LA-14068-H in special issue]; Michael P. Bernardin