Hiroshima_ The World's Bomb - Andrew J. Rotter [56]
FOUR - The United States I: Imagining and Building the Bomb
The high-level British scientific committee inspired by the Frisch— Peierls memorandum was meeting with regularity by the middle of spring 1940. Its chair, G. P. Thomson, thought it needed a name, so in June 1940 he christened it the MAUD (or Maud) Committee, imagining he was appropriating a fragment of code from a telegram sent to England by Lise Meitner—though in fact Meitner had only wished to contact Niels and Margrethe Bohr’s former governess, Maud Ray, who lived in Kent. The MAUD Committee coordinated and encouraged rudimentary bomb research. It employed a good number of so-called ‘alien’ scientists, or ‘exotics’ as some called them: Frisch and Peierls, Francis Simon, who did advanced work on isotope separation, Hans von Halban and Lew Kowarski, who had collaborated with Frederic Joliot in Paris, and methodical Klaus Fuchs. They were not allowed to work on radar or own bicycles without permission. They were permitted to do nuclear research. Under MAUD auspices, there occurred a number of remarkable advances in nuclear physics and chemistry that would be consolidated the following year.1
1. The MAUD Committee and the Americans
MAUD’s work was closely monitored by Frederick Lindemann, the Oxford physicist, recruiter to Britain of Central European scientists, and confidant of Winston Churchill. The committee and its scientists also cooperated fully with the Americans. John Cockcroft, the Cambridge physicist and an important figure in MAUD, corresponded frequently with American colleagues and visited the United States and Canada in the fall of 1940. British scientists also entertained high-level American visitors. James Conant, eminent chemist, president of Harvard, and head of the National Defense Research Committee (NDRC), established to follow and encourage the work of the American nuclear physics community, crossed the Atlantic in February 1941. He met Halban at Cambridge; the Austrian-born scientist discoursed on heavy water and chain reactions. (‘Look,’ said an uncomfortable Conant, ‘you’re not supposed to talk to me about this thing.’) But back in London Lindemann raised the issue too, confiding in Conant over lunch that it might be possible to make a powerful explosive by slamming together two pieces of U-235. Conant was followed to England by the nuclear physicist Kenneth Bainbridge. Invited to attend a MAUD meeting, Bainbridge was, like Conant, surprised to learn that British scientists had ‘a very good idea of the critical mass and [bomb] assembly’, and hoped to ‘exchange personnel’ and thus information with the Americans. Back home in early June, Bainbridge told the University of Chicago physicist Arthur Holly Compton and a group assembled at Harvard of British achievements and ambitions, including the hope that a nuclear explosive might be ready for use in two years.2
Similarly, the NDRC ordnance specialist Charles Lauritsen sat in on a MAUD meeting in early July, at which he heard Thomson give a preliminary survey of what was called, simply, ‘MAUD Report’. (The final version came at the end of that month.) The conclusions of the report echoed the optimism and determination previously expressed to Conant and Bainbridge. Building a uranium-based bomb was a project ‘of the very highest importance’, so the work must move forward ‘as rapidly as possible’. There should be more investigation of fission in U-235, an effort