A number of the fission bomb assembly methods proposed during the summer conference on bomb design held at UC Berkeley by <a href="//commons.wikimedia.org/wiki/Robert_Oppenheimer" class="mw-redirect" title="Robert Oppenheimer">Robert Oppenheimer</a> in 1942 during the <a href="//commons.wikimedia.org/wiki/Manhattan_Project" class="mw-redirect" title="Manhattan Project">Manhattan Project</a>. These drawings are taken from the "Los Alamos Primer" — Los Alamos Report LA-1 (declassified 1965) — and were created in 1943 by Robert Serber.
Robert Serber
Attribution
Excerpt from <a href="//commons.wikimedia.org/wiki/File:Los_Alamos_Primer.pdf" title="File:Los Alamos Primer.pdf">File:Los_Alamos_Primer.pdf</a>