Manhattan District History; Book VIII - Los Alamos Project (Y); Volume 2 Technical

Page 4

The euppleseat, written by others, follcnn in general the •SJne methode of ie tha lea.et diaturbance of the contlnlllt7 of the vhole. kTT Participation, and a number of other•.

Page 5

devoted to t he wartime developn.ent of the atomic bomb. This branch of the DSM organization was created ear)Jr in the year 1943. During t he period of its existence it has been the center of activities connected with bomb development and production, as distinguished from the developrrent and production of nuclear The hi.!5tor.}' of all DSM activities possesses a peculiar interest and i mportc.nce, not only because of the remarkable achievements and potentialities of n~lear technology, but also because of the ftartime character a nd motivation of its initial develoμnmt. Because of its large socia.l cost, a scrupulous accounting of the entire venture is evidently required. Froject Y has been, of a crucial position. The vmrtime success of the entirE! undertaking has depended upon its success. The nature of the present chronicle of IDs Alamos is thus detenninedJ by the requirement that there exist a careful accounting of its technical, administrative and. policy-making activities. This document is a record, nc:_>t an interpretation_ of events. Within the limitations thus implied, however, it has n<>t been forgotten tbat the events recorded have taken place within a vrider context, t he evolut ion of organized ocientific research and of world technology. The problems of organization and policy that lie here , sharpened by t he advent of control over nuclear energies, will call for the most . searc hir.ie interpretation and analysis. It is hoped that in this record of fac~

Page 6

'I b:i s is the neces sary lJmission of !Mny subj ective fac t ors. The 1'UOcess of is o ocmpl ex and uncerttt i n Ii ventur t-1 as Los Alamos depen~ s upon its ability to ext end knowl1icge of th e explicit nnd publicly a.ccountabJe sort at which science ur ,fo1d inr o!' posi>ib i1iti es ac q uired t h is ap pearance only thronp;h the interaction !inc on occas ion the clr..sh of op inion, in an a.tmoa.phere domir..o.ted by the ?r ::rnl ew. t ic and t ne uncertain. The omis&ion is inevi te. bl f' in an account which pa.tt~rr~ of c! '3 velopment is so largely a rational one h a tributt! to the unity of p urp%e 0 f o.11 concerr.ed i admini::;tra.tors anc scientists, civilian anc military. A lal'"ge share of the credit t~t t ~i s has b e en so rr.ust be t;iven to the Dir ector, Dr. Op penheimer; net onJy for his general leadership, but a.lso more specifically boc~usE:· he underatooc the necessity for unity and sought in every The 1·ea.der wi1 i obser~e frorr. t he tutle of contents tha.t the history c f Los Alamo f, ho.::; bte n divided into two pe:-ioc!s. the first ext ericing to Auguat,

Page 7

it does con:e at the t ime of an extensive e:.dministration reorganization. The . ree l purpose of this division is to permit some chance to summarize and conr,c ct 'activities which, a lthough const.'.lr;tly interrf!lated'- in practice, must be written a bout in separa te cha pters. And althoug h nc distinct separa tion into pha.ses :la possible, t he d:.. t e chosen mc.rks as welJ. as any the transition at Los Ala.mes from n ,sea rc h t o dev€lopment, from scheruat i za tion to engineering. from many mer. bers of tl.e Los /d ..amos L:l.boratory. In particular I wish to thank me in ga thering data, in dr.::..fting various sections of the report, or in extenslve critic i sm of ea.rlier drafts. I wish especially to thank Emily Morrison and Priscilla Duffield for ingenious r~searches in the records of an organization that was fre 1.1uent.ly too busy to be concerned with posterity. Mr•· Morrison has prepared the graphical ma. terial, has draftEd several of the chapter~, and has given invaluable genera l assistan_ce. Finally it must be made clear that all errors of f a ct in this rec ord are the sole responsibility of the author"

Page 8

TAH LE OF C'OMIENTS Organ ha ti on The April Conferences Report. of ReYiewing Ccmmlttee CRAFTER II I • THI PERIOO APRIL 1943 - AUGUST 19440 Salary Polloy and Admini1tration Per a onn el J'f'OC\U"em en t Pe. t.,,nt; Off foe

Page 9

The Oisoovery ~r Pu Organ 1.ta ti on Energy Speotrvm ot Fission Bel.ttrona Scattering E~p•riments. Choice of Tamper The lta ter Boiler Gun Design. Proving.- Interior Balliatioa Proj•otile, Target and Initiator Deeign Arming and ·'F'l..i sing Intr oduc t i on

Page 11

t.18 of Energy in the Presence ot Low Temperature Energy Loes through Thermal Conduction Deuterium aJXi Tritium Reaction Cross Sections The Water Boiler CHAPTER XIV - ORDNANCE DIVISION Implosion Studies: The X··F.aJ" Method

Page 12

Eicplosives De·welopnent and Production Uranium Puritiea.tion and Recnery Preparationtt tor the Trinity Test

Page 14

Objective and Organization 1. 1 During the early period of the DSM rI'oject t h$ most urgent Nquirement was the_ large scale product.ion of nucil.ear explosives. There could separation of u235 and t.h• production ot Pu · preaented major scientific and indu.'!ltria~ probleD18. Until these probleru.<3 were o.n the i r way to solution, there mechanism ot the nuclear explosion. Ttrl.a work had in tact not progressed. very tar beyond what was need~d to show the probable feasibility and ·effecti veness ot the ( 1 .had become clear that the scientif'ic and engineering problem8 camected with the developilent of such· a weapon and its use in canbat called tor earJ.¥ and intai•ive effort. At this time overall responsibility for the physics ot bCIDb develoμie nt had been given to the Metallurgical I.abor~ tory of the Universit y ot Chicago. Thia organization was geared, however, to its own problems, and in part icular to •- the developnent of the slow neutron chain re<\ ~tion as a. source of pluton ium., Work on fast neutr on chain r eactions , looking toward banb develoμnent, was going 1.2 The t i.rat .step toward a ino:re concer t ed program. ot banb de~elo~nt Ca li.f ornia as Director of this branch t1:f the work. Although associated with the . Californi a with a small group of theoretfoal physicists . In hie coordination of

Page 15

1.3 L'.l.te in June, a confere nce was called in Berkeley to dtscuss the theory of the bomb and plan work for th(' future~ Pre ~~: nt at this conference were devoted to a new type of explosive reaction that had been ··onsidered by Teller, . a ~hermo-nuclear reaction in deuteriwn. ( 1.47) There was some discu..<J~ion of the Uieory of the shock-waves produced in the chain reaction explosion, on the bas is of \-lOrk that h.'.1'.d been done by Bethe and Van Vleck. Another topic was the damage to be expected i ..r1 terms of energy~release. This was discussed largely in a qu;:.lit.o.tive way, by scaling up from small explosiol'.l3 and by comparison with such disasters as the Halifax explosion. At this conference, there was a thorough review of' theoretical and ex:rerimental work that hr~ ct been done. By this time enough information was available so that there were no large gaps in the picture. Rough but qualitatively reliable data were available from work that had been done under Metallurg ical Laboratory contracts; a good deal of i·elevant information had and Dirac. British theoretical results were also available. Although a fair part of the discussion at the conference was not along what subsequently turned out to be the main line of development, it served to clarify basic ideas c'l.nd define basic problems. It also served to make clea r that the develoμnent of the fission bcmb would require a major scientific and technical effort9 l .. 1+ Follotting the summer conference in Berkeley there were a. number of conference~ in CM.cago with experimentalists. At this time a number of sub-contracts had a.lready been let, by the Uniirersity of Ch.~.c:-.igo, for the r0 u.rpos1~ of pursuing the imtestigation of nucl6!:!r properties relevant to bomb designs,. A loose organization waq_ fomed, including the sub-projects at. Rice Ins t itute, The Department of Corr1el'- UnivBrsity 3 the University of Chica go, a nd the Universlty of California..

Page 16

1. 5 By Octobar of 1942, it. hr. d been decided tl·a t t he m.<J.gnitude of the difficulties involved made necessary tn.e f'o:r'lIBtion of a new proj ect. Even the hampered b1 the lack of an organiza~ion united in one locality; it was clear that 1 . 6 The site ot ProJect Y was selected in November cf 1942. It was t he Los Alamos Ranch School, located on an isolated mesa in th~ Pajarito Plateau by highway about ~ mil'a north and wes t of. Santa Fe ~ New Mexico. The reasons tor the selection of such a site are o! sane interest, and throw light on the character of the new project. First, the r e woul~ be need of a large proving ground, with a climate isuitable for outdoor work in winter-. Second, the site would have to be remote frcrn. both seacoasts and the poBoib:Uity - at that time not negligible - ot attack. Locations might have been found w~ich satisfied these requirements but were more accessible. The inaccessibility of Los Alamos, however, would not have created serious problems for a small project,· such as this was · 1zt ended tQ... be. Its subsequent growth to many times its original size was not foreseen. In the was a dec i ding factor in favor of this locat i on. Project froan the auapic.es of t he Office of Scient ific Re~earch a.nd Develoi:-nent to that of t hf) Manhattan. District. The highest · degree of sec recy had to be ma.inta~.ned

Page 17

consideration was tbe geograpM.cally enforced isolatior. of project personnel, CJ which would minimize the posaibility that secret in!onnation might diffuse 1.8 The choice of a site, dstermined by the considerations suggested views, nevertheless, ·had a bearing on the selection, and served to strengthen in the minds of the military authorities the arguments for isolationa The task that confronted the project was not one o{ development and engineering in the ordin~ry sense. It wa~ one of intensive and highly organized research in a region that ha4, been ,only schematically explored. It required collaboration ot physic iste, chemists, metallurgi.ste, and engineers in solving difficult problems, many of which could not even be anticipated until the work was well under way. Th6 need for collatloration was ma.de emphatic by the imposition of a definite time-scalea The bomb had to be read,y tor production by the t.in:e usable quantities of nuclear explosive became available. T'o carr1 out therefore o! decentralization and mutual confidence. To thia end, . free coamunication.within the laboratory is indispensable. felt and stated by the scientific staff members, the normal military procedure for protecting secret information is· one of subdivision. Fach individual oJ• working unit has access only to infonnation immediately :relevant to the work beiP.g pursued,. This conflict of ciantif j.c and. military requirt:mentai is, of course, ste.ff were, or had been, engaged in other vn.:i.r research, a nd vwre from previous exper ience convinced of' the evils of obs t.ruct.ine the normal f ow of infoI"1$ t i on within a laboratory.. They were •rigorously opposed to C<:l'npa rtment.alizat.ion.

Page 18

requirements could be met by allowing intern-'.11 freed om and i mpos ine; instead more severe externa l restrictions than might otherwise aμμear neCE•ssary. The adoption cf such a folicy made necessary. the choice of an isolated location for 1. 10 The Les Alamos site, together with a large surrounding apea, W<'l.S established a s a military reservation. 'rhe community 1 fenced and guarded, was made an army post. The laboratory, in turn, wa~ built within an inner fenced and guarded area , called the "'technica l Area". Both the military and t e chnical execut.ive res !-·on;:;ibility for the work. The Comnanding Officer reported dlrectl.y to Gener::il Groves , he was responsible for the conduct of military personnel, the maint enanc e of adequate living conditions, prevention of trespass, and special guardin~. Oppenhe~ner, as Scientific Director, was also responsible to Genera l Gr oves~ who had as his tec hnica l advisor J. B. Conant. In addition to his technical responsibilities, the Director was made responsible for the policy and administration of security. This provision represented a guarantee that there would oe no military control of the exchange ot information among scientific staff members, and a t the same time fixed responsibility for the maintenance of security w ider t hese conditions. In carrying out his responsibilities for security, the Director was to be given the ass i s tance and advice of a Military Intelli.gence Office1. ~l The financial and procurement operat fons of the Project were period of oper~tion~, when the3e had largely to do w. th the employment of personn13l and es ta b.lishing a procurement office, the Uni1 ersity a cted i.mder a

Page 19

This contract, with subsequent supplementa l agreements, had be en the forrr..al basis of the Project's operation throughout the rest of its history. 1.12 The financial operations of the University at Los Alamos were provided for by the appointment of a resident Business Officer, J . A. D. Muncy. The procurement of roaterials was arranged through a dual organization. In addition to the procurement division of the Project, the University establisred in Loa Angeles a special purchasing office. This arrangement v:as dictated primarily by reasons · of security. It might be posslble to determine both t .he nature and progress of the work !rom· a knowledge of the nature and volume o! its procurement operations. According to the procedure established, goods ordered through the Los Angeles office were received there and transshipped to Los Alamos. The procurement offices at the site were pl.aced under the direction of D. P. Mitchell. Mitchell had for many years been in charge of laboratory procurement for the Physics Department of Colwnbia University, and most recentlJ' for a National Defense Research Council project at that Uni'-'3 rsity. l.l3 A statement of the r esponsibilities of the military and , contractor organizations, and & directive outlining the scope and purpose of Project Y, were set forth in a letter to Oppenheimer dated February 25, 1943, fran General Groves and Conant. Thi3 letter contains also a sta~ement of intention concerning the future organiz~tion of the project. According t o this statement i t was anticipated that the Project would remain an organizatj_on of the OSRD t.Y}"">e during the first period of its operation, when it would be engaged . ma.inly in nu.clear r esearch . puring a later period of operation, when the project woul d be involved in the dangerous work of bomb development and as sembly, it would be conduc ted on a military basis, with oppor-t..unity f or its civilian staff membera to be commi3aioned as officers. This anticipated reorganizatior. pr·oved unnecessar y. Difficulties that had be er. expected with the initia l …