New evidence can be found that Japan was developing an atomic bomb at the end of World War II

In August 1945, atomic bombs were dropped on Hiroshima and Nagasaki, Japan. Japan has adopted the ' Nuclear Three Principles ' as its national policy as the only atomic bombed country to which an atomic bomb was dropped in the war, but at the end of World War II, the military was secretly developing an atomic bomb. New supporting material has been discovered.

Discovery of Japanese military atomic bomb development materials Kyoto University exempts GHQ from being seized: Kyoto Shimbun
http://www.kyoto-np.co.jp/top/article/20150625000018

New evidence of Japan's effort to build atom bomb at the end of WWII-LA Times
http://www.latimes.com/world/asia/la-fg-japan-bomb-20150805-story.html

Newly discovered is the data on the development of a centrifugal separator for uranium enrichment, which was stored at the Kyoto University Radioisotope Research Center. This is a record of the development that was being carried out in the laboratory of Professor Fumaku Arakatsu of Kyoto Imperial University (now Kyoto University) who had been requested to develop an atomic bomb by the former Japanese Navy during the Pacific War. And related materials have been found.

After the end of the war, the Allied General Command (GHQ) seized all the development materials for the atomic bomb at Kyoto Imperial University, and most of the details remained unknown because it was classified as confidential in the United States. However, the discovery of what was left unconfiscated this time is a valuable discovery for examining the history of Japanese science and technology at the time, the Kyoto Shimbun reports.

The research notes discovered were signed by Professor Sakae Shimizu and Professor Emeritus of Kyoto University, who belonged to the laboratory of Professor Fumaku Arakats during the war, and were written around the end of the war from October to November 1944. It seems to be a thing. The time is ambiguous because the date was written in the Imperial era.

In the notebook, the numerical values and materials related to the centrifugal separator necessary for performing the 'uranium enrichment' necessary for the development of the atomic bomb are described, and it seems that overseas related papers are photographed and pasted .. There is also a page in the notebook that describes the materials required to actually manufacture the centrifuge, and in the material list, the necessary material names such as 'super super duralumin' and their diameter and length are described in detail. I am.

Approximately a month after the atomic bomb development documents that were free from GHQ seizures were found, centrifuge design drawings were found elsewhere.

New drawing of atomic bomb research in Japan during World War II Uranium concentrator at Kyoto University 'Completed on August 19, 1945' (1/2 page)-Sankei News
http://www.sankei.com/life/news/150726/lif1507260018-n1.html

Two points were discovered: a design drawing of the centrifuge that seems to have been originally designed in the laboratory of Professor Fumaku Arakats, and a drawing by the Tokyo Keiki Seisakusho (currently Tokyo Keiki) that was entrusted with the design. It seems that Professor Akira Masaike, Professor Emeritus of Kyoto University, who is investigating the history of nuclear physics, discovered it in the relics of Professor Sakae Shimizu.

The drawing designed by Professor Arakatsu's laboratory was created in March 1945 and is labeled 'Air Turbine Ultracentrifuge'. In addition, the drawing of Tokyo Keiki says 'Completion August 19, 1945', and it is expected to be completed just a few days after August 6 and August 9 when the atomic bomb was dropped on Japan. It seems that However, it is said that the centrifuge manufactured by the company was actually lost during the air raid.

The atomic bomb development commissioned by the former Japanese Navy is called 'F research' after the acronym for 'fission' and is said to have begun in 1948 at the end of the war.