Talk:Japanese nuclear weapon program/@comment-78.149.200.119-20160717092933

                                            Notes on the ‘Tonizo’ documents.

TONIZO is the abbreviation for To Dai Ni Zohisho, Tokyo 2nd Arsenal.

The documents consist of four hand written reports, the first of five sheets 26 x 36cm, ie 10 pages dated April 1943 and titled “On Uranium (U)”. It is a general review of atomic research world wide.as well as that pertaining to Japan. The author is not recorded but is surmised to be Takeo Yasuda as he is known to have spent some time in Germany on military training and no doubt learnt some of the language. This report contains a part translation of  Dr. Alfred Stettbacher’s  paper ” Der amerikanische Super-Spengstoff U-235”  the American super explosive U-235, Nov. 1940. Stettbacher writes (translation from german) of an atomic bomb being able to ‘destroy entire military complexes, melting Tanks and Bunkers’. The latter bring translated into Japanese as the coal store of a ship and clearly has made use of a dictionary.

The author’s knowledge is somewhat limited as an example, ‘According to the US Naval institute (1940), Nishina has succeeded in changing U238 to U235 and it seems they have an interest in this matter.’ This is of course a miss understanding of Nishina discovery of U237 and symmetrical fission.

This document also contains a shortened version of Tokutaro Hagiwara’s lecture given in May 1941 in Yokohama to the Navy, titled ‘Uranium 235 Chobakuritsu sai Genshi’ the super expolosive nature/properties of the U235 atom’. Explosive is normally ‘bakuhatsu’ but Hagiwara used ‘ritsu’ form, meaning to tear or tear apart. An unusual form but understandable.

 The interpretation of part has led to the proposal that Hagiwara theorised on the possibility of fusion and the hydrogen bomb. Professor Fukui of Nagoya University and Mr. Kaji of Tokyo Institute of Technology have shown that the Kanji in this script is not the same as appeared in the printed version of Hagiwara’s lecture. Only the first half of the Kanjis are identical. The Kanji in Hagiwara’s lecture ‘cho’ meaning super was replaced by ‘ki’ meaning awaken, initiate or trigger, as in’ Okite kudasai’  please wake up. Or if it’s your teenage son, a firm ’Oki-nasai !’ which is not a request.

A more critical sentence is ‘Tekito nodo suiso to no kongobutsu no aru’ which is talking about mixing (kongobutsu) the U235 with hydrogen (suiso), tekito meaning suitable.’ The ‘no’ in ‘nodo’ has the meaning of strength, thickness, density but not specifically density which is mitsudo, ‘do ’indicating a measure of. The word has the sense that we talk of a strong cup of tea or the number of sugars put into the tea. The significance of this word is in the fact that a fission neutron requires on average 18 collisions with a hydrogen atom to reach thermal energies where it’s probability of causing fission of  U235 is some 500 time greater. That number being dependent on thickness and density of hydrogen. The idea of an atomic bomb on these lines was not uncommon at the time.

The reports for July 43, Feb.44 and Nov.44, are 5 or 6 pages 18 x 25 cm and cover proposals, explanations and progress etc. The hand writing appears similar and is assumed to be that of Ishida. In some instants due to a kanji requiring many strokes a simpler one having the same sound but with an unrelated meaning, has been substituted. Also a number of words are followed by katakana to aid pronunciation. Some of the phases are old fashion or ‘mans’ words which is not surprising as Nishina was said to have been very much a ‘Meiji man’.

<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"TimesNewRoman",serif">Due acknowledgement is made to the Riken Institute, Tokyo for the facsimile of these documents.