University, Kyoto. Arakatsu had spent some years studying abroad including at the Cavendish Laboratory at Cambridge under Ernest Rutherford and at Berlin University under Albert Einstein. Next to Nishina, Arakatsu was the most notable nuclear physicist in Japan. His team included Hideki Yukawa, who would become in 1949 the first Japanese physicist to receive a Nobel Prize. Early on in the war Commander Kitagawa, head of the Navy Research Institute's Chemical Section, had requested Arakatsu to carry out work on the separation of Uranium-235. The work went slowly, but shortly before the end of the war he had designed an ultracentrifuge (to spin at 60,000 rpm) which he was hopeful would achieve the required results. Only the design of the machinery was completed before the Japanese surrender. After Arakatsu and Nishina's meeting, in Spring 1944 the Army-Navy Technology Enforcement Committee formed due to lack of progress in the development of Japanese nuclear weapons. This led to the only meeting of the leaders of the F-Go Project scientists, on July 21, 1945. After the meeting, nuclear weaponry research ended as a result of the destruction of the facility that housed isotope separation research, known as Building 49. Shortly after the surrender of Japan, the Manhattan Project's Atomic Bomb Mission, which had deployed to Japan in September, reported that the F-Go Project had obtained 20 grams a month of heavy water from electrolytic ammonia plants in Korea and Kyushu. In fact, the industrialist Jun Noguchi had launched a heavy water production program some years previously. In 1926, Noguchi founded the Korean Hydro Electric Company at Konan (now known as Hungnam) in north-eastern Korea: this became the site of an industrial complex producing ammonia for fertilizer production. However, despite the availability of a heavy-water production facility whose output could potentially have rivalled that of Norsk Hydro at Vemork in Norway, it appears that the Japanese did not carry out neutron-multiplication studies using heavy water as a moderator at Kyoto. Postwar aftermath On 16 October 1945 Nishina sought permission from the American occupation forces to use the two cyclotrons at the Riken Institute for biological and medical research, which was soon granted; however, on 10 November instructions were received from the US Secretary of War in Washington to destroy the cyclotrons at the Riken, Kyoto University, and Osaka University. This was done on 24 November; the Riken's cyclotrons were taken apart and thrown into