Manhattan -projek

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Die Manhattan-projek was die kodenaam vir die poging van Amerika om 'n funksionele atoomwapen tydens die Tweede Wêreldoorlog te ontwikkel. Die omstrede skepping en die uiteindelike gebruik van die atoombom het sommige van die wêreld se voorste wetenskaplike gedagtes sowel as die Amerikaanse weermag betrek - en die meeste werk is gedoen in Los Alamos, New Mexico, nie die stad New York waarvoor dit was oorspronklik vernoem. Die Manhattan -projek is begin as gevolg van die vrees dat Duitse wetenskaplikes sedert die dertigerjare aan 'n wapen gewerk het met behulp van kerntegnologie - en dat Adolf Hitler bereid was om dit te gebruik.

Amerika verklaar oorlog

Die agentskappe wat tot die Manhattan -projek gelei het, is die eerste keer in 1939 deur president Franklin D. Roosevelt gestig, nadat Amerikaanse intelligensie -agente berig het dat wetenskaplikes wat vir Adolf Hitler werk, reeds besig was met 'n kernwapen.

Aanvanklik het Roosevelt die Advieskomitee vir Uranium gestig, 'n span wetenskaplikes en militêre amptenare wat die potensiële rol van uraan as 'n wapen moet ondersoek. Op grond van die bevindinge van die komitee, het die Amerikaanse regering begin met die finansiering van navorsing deur Enrico Fermi en Leo Szilard aan die Universiteit van Columbia, wat gefokus was op radioaktiewe isotoopskeiding (ook bekend as uraanverryking) en kernkettingreaksies.

Die advieskomitee oor Uranium se naam is in 1940 verander na die National Defense Research Committee, voordat dit uiteindelik in 1941 herdoop is tot die Office of Scientific Research and Development (OSRD) en Fermi bygevoeg het tot sy lede lys.

In dieselfde jaar, na die Japannese aanval op Pearl Harbor, het president Roosevelt verklaar dat die VSA die Tweede Wêreldoorlog sou binnegaan en met Groot -Brittanje, Frankryk en Rusland sou aansluit om teen die Duitsers in Europa en die Japannese in die Stille Oseaan -teater te veg.

Die Army Corps of Engineers het in 1942 by die OSRD aangesluit met toestemming van president Roosevelt, en die projek het amptelik tot 'n militêre inisiatief verander, met wetenskaplikes wat 'n ondersteunende rol vervul het.

Die Manhattan -projek begin

Die OSRD het die Manhattan Engineer District in 1942 gestig en dit in die gelyknamige stad New York gevestig. Kolonel Leslie R. Groves van die Amerikaanse weermag is aangestel om die projek te lei.

Fermi en Szilard was nog besig met navorsing oor kernkettingreaksies, die proses waardeur atome skei en interaksie het, nou aan die Universiteit van Chicago, en die uraan suksesvol verryk om uraan-235 te produseer.

Intussen het wetenskaplikes soos Glenn Seaborg mikroskopiese monsters van suiwer plutonium vervaardig, en die Kanadese regering en militêre amptenare was besig met kernnavorsing op verskeie plekke in Kanada.

Op 28 Desember 1942 het president Roosevelt die oprigting van die Manhattan -projek goedgekeur om hierdie verskillende navorsingspogings te kombineer met die doel om kernenergie te wapen. Fasiliteite is opgerig op afgeleë plekke in New Mexico, Tennessee en Washington, asook in Kanada, vir hierdie navorsing en verwante atoomtoetse.

Robert Oppenheimer en Projek Y

Die teoretiese fisikus J. Robert Oppenheimer het reeds aan die konsep van kernsplyting gewerk (saam met Edward Teller en ander) toe hy in 1943 as direkteur van die Los Alamos Laboratory in die noorde van New Mexico aangewys is.

Los Alamos Laboratory - waarvan die skepping bekend gestaan het as Projek Y - is formeel op 1 Januarie 1943 gestig. Die kompleks is waar die eerste Manhattan Project -bomme gebou en getoets is.

Op 16 Julie 1945, in 'n afgeleë woestyn naby Alamogordo, New Mexico, is die eerste atoombom suksesvol ontplof - die Drie -eenheidstoets - wat 'n enorme sampioenwolk van ongeveer 40 000 voet hoog gemaak het en die atoomtydperk ingelui het.

Wetenskaplikes wat onder Oppenheimer werksaam was, het twee verskillende soorte bomme ontwikkel: 'n ontwerp op uraan genaamd "die klein seuntjie" en 'n op plutonium gebaseerde wapen genaamd "die vet man". Met albei ontwerpe in Los Alamos, het dit 'n belangrike deel van die Amerikaanse strategie geword wat daarop gemik was om 'n einde te maak aan die Tweede Wêreldoorlog.

Die Potsdam -konferensie

Terwyl die Duitsers groot verliese in Europa gely het en oorgawe nader, was die konsensus onder Amerikaanse militêre leiers in 1945 dat die Japannese tot die bitter einde sou veg en 'n grootskaalse inval in die eilandnasie sou dwing, wat lei tot aansienlike slagoffers aan beide kante.

Op 26 Julie 1945, tydens die Potsdam-konferensie in die geallieerde besette stad Potsdam, Duitsland, het die VSA 'n ultimatum aan Japan gestel-oorgawe onder die voorwaardes uiteengesit in die Potsdam-verklaring (wat onder meer die Japannese versoek het om 'n nuwe, demokratiese en vreedsame regering vorm) of 'vinnige en volslae vernietiging in die gesig staar'.

Aangesien die Potsdam -verklaring die keiser geen rol gespeel het in die toekoms van Japan nie, was die heerser van die eilandnasie nie bereid om sy voorwaardes te aanvaar nie.

Hiroshima en Nagasaki

Intussen het die militêre leiers van die Manhattan -projek Hiroshima, Japan, geïdentifiseer as 'n ideale doelwit vir 'n atoombom, gegewe die grootte en die feit dat daar geen bekende Amerikaanse krygsgevangenes in die gebied was nie. 'N Kragtige demonstrasie van die tegnologie wat in New Mexico ontwikkel is, is nodig geag om die Japannese aan te moedig om oor te gee.

Sonder enige oorgawe-ooreenkoms, het die Enola Gay-bomwerpervliegtuig op 6 Augustus 1945 die nog ongetoetste 'Little Boy'-bom ongeveer 1,900 voet bokant Hiroshima laat val, wat ongekende vernietiging en dood veroorsaak het oor 'n gebied van vyf vierkante myl. Drie dae later, met nog steeds geen oorgawe nie, op 9 Augustus, is die bom "Fat Man" oor Nagasaki, die terrein van 'n torpedo-aanleg, neergegooi en meer as drie vierkante kilometer van die stad vernietig.

Die twee bomme gesamentlik het meer as 100 000 mense doodgemaak en die twee Japannese stede gelyk gemaak.

Die Japannese het Washington, wat na die dood van Roosevelt onder die nuwe leiding van president Harry Truman was, in kennis gestel van hul voorneme om op 10 Augustus oor te gee en formeel oorgegee op 14 Augustus 1945.

Nalatenskap van die Manhattan -projek

Met die ontwikkeling van wapens wat bedoel is om die einde van die Tweede Wêreldoorlog as sy doel te bereik, is dit maklik om te dink dat die verhaal van die Manhattan -projek eindig in Augustus 1945. Dit is egter nog lank nie die geval nie.

Na die einde van die oorlog het die Verenigde State die Atomic Energy Commission gestig om toesig te hou oor navorsingspogings wat ontwerp is om die tegnologieë wat onder die Manhattan -projek ontwikkel is, op ander velde toe te pas.

Uiteindelik, in 1964, het die destydse president Lyndon B. Johnson 'n einde gemaak aan die effektiewe monopolie van die Amerikaanse regering op kernenergie deur privaatbesit oor kernmateriaal moontlik te maak.

Die kernsplytingstegnologie wat deur die ingenieurs van die Manhattan -projek vervolmaak is, het sedertdien die basis geword vir die ontwikkeling van kernreaktors, vir kragopwekkers, sowel as ander innovasies, insluitend mediese beeldstelsels (byvoorbeeld MRI -masjiene) en bestralingsterapieë vir verskillende vorme van Kanker.

Bronne

Manhattan: die weermag en die atoombom. Amerikaanse weermag sentrum vir militêre geskiedenis.
Die Manhattan -projek - sy verhaal. Amerikaanse Departement van Energie: Kantoor vir Wetenskaplike en Tegniese Inligting.
Leo Szilárd, 'n verkeerslig en 'n stukkie kerngeskiedenis. Wetenskaplike Amerikaner.
J. Robert Oppenheimer (1904—1967). Atoomargief.

Manhattan -projek historiese bronne

Die Amerikaanse departement van energie (DOE) het 'n wye verskeidenheid in-gedrukte, aanlyn en persoonlike persoonlikhede van die Manhattan-projek ontwikkel en beskikbaar gestel aan die publiek. Dit sluit in geskiedenis, webwerwe, verslae en dokumentversamelings, en uitstallings en toere.

DOE -geskiedenis van die Manhattan -projek: Geskiedenisse wat deur die Departement vervaardig is, sluit in Die Manhattan -projek, wat 'n kort oorsig bied, en die langer, op 100 bladsye (insluitend die "Fotogalery" van 35 bladsye) Die Manhattan -projek: maak van die atoombom. Hierdie nie-tegniese, hoogs leesbare verslae is gerig op die algemene leser. Gepubliseer in 1962, Die Nuwe Wêreld, 1939-1946, was die eerste belangrike geskiedenis van die Manhattan -projek. As Deel 1 van die amptenaar Geskiedenis van die atoomenergiekommissie reeks, Die Nuwe Wêreld het beide ongeklassifiseerde en nog steeds geklassifiseerde bronmateriaal gebruik en baie onthul wat voorheen nie bekend gemaak is nie. Die Nuwe Wêreld en die U.S. Army Center of Military History's Manhattan: die weermag en die atoombom wat in 1985 vrygestel is, bly die mees gedetailleerde gepubliseerde verslae van die Manhattan-projek en is by groot biblioteke beskikbaar.

In Julie 2013 het die departement begin Die Manhattan -projek: hulpbronne, 'n webgebaseerde, gesamentlike samewerking tussen die departement se kantoor vir klassifikasie en sy geskiedenisprogram. Die webwerf is ontwerp om inligting en dokumentasie oor die Manhattan -projek te versprei aan 'n breë gehoor, insluitend geleerdes, studente en die algemene publiek. Die Manhattan -projek: hulpbronne bestaan uit twee dele: 1) Die Manhattan -projek: 'n interaktiewe geskiedenis, 'n webwerfgeskiedenis wat ontwerp is om 'n insiggewende, leesbare, omvattende oorsig van die Manhattan-projek te bied, en 2) die Manhattan District History'n Geklassifiseerde geskiedenis met meerdere volumes in opdrag van generaal Leslie Groves aan die einde van die oorlog, wat 'n groot hoeveelheid inligting in 'n sistematiese, geredelik beskikbare vorm versamel het en uitgebreide aantekeninge, statistiese tabelle, grafieke, ingenieurstekeninge, kaarte en foto's bevat. Al 36 volumes van die Manhattan District History, gedeklassifiseer en gedeklassifiseer met redaksies, word die volledige teks aanlyn beskikbaar gestel.

Geskiedenis van die Manhattan -projekwebwerf: Bykomende bronne vir inligting oor die Manhattan -projek kan gevind word op die volgende terreine wat deur die departement se terreine en laboratoriums aangebied word: die Los Alamos National Laboratory Ons geskiedenis, die Y-12 National Security Complex Y-12 Geskiedenis, die geskiedenis van die Oak Ridge National Laboratory en Hanford's Hanford geskiedenis. In samewerking met die opening van die Manhattan Project National Historical Park op 10 November 2015, het die departement die webwerf K-25 Virtual Museum bekendgestel.

Manhattan Project Images: DOE bied toegang tot 'n verskeidenheid Manhattan Project -beelde via sy Flickr -webwerf.

Manhattan Project Records: Die departement gaan voort om gedeklassifiseerde verslae en dokumente wat verband hou met Manhattan-projek op sy OpenNet-webwerf bekend te maak. Hierdie soekbare databasis bevat bibliografiese verwysings na alle dokumente wat gedeklassifiseer is en na 1 Oktober 1994 in die openbaar beskikbaar gestel is. Sommige dokumente kan in volledige teks besigtig word. By die National Archives and Records Administration (NARA) is toegang tot ongeklassifiseerde en gedeklassifiseerde versamelings van die Manhattan Project -rekords verkry. Die kern administratiewe rekords van die Manhattan Engineer District (MED) kom uit Oak Ridge, Tennesee, en is oorgeplaas na die NARA se Suidoos -streek in Atlanta, Georgia. Ook in Atlanta is die MED -operasionele afdeling en ander Oak Ridge -rekords ongeklassifiseer/gedeklassifiseer. Geklassifiseerde MED -rekords is na die NARA -hoofkwartier (Argief II in College Park) gestuur.

Manhattan -projek - GESKIEDENIS

Die Manhattan -projek het nie net gebeure aan die gang gesit wat die uitkoms van die Tweede Wêreldoorlog sou versterk nie. Die Manhattan -projek het ook die hele manier waarop oorlogvoering vir ewig geveg word, verander. Dit het ook bygedra tot 'n volledige verandering in die globale posisie van supermoondhede, sou supermoondhede en hul bondgenote wees.

Die oorspronklike doel van die Manhattan -projek (1942 tot 1945) was natuurlik om die Tweede Wêreldoorlog te beëindig. Alhoewel dit die doelwit was, het nie eens die wat die kern van die projek was, werklik besef hoe hulle die geskiedenis vir ewig sal verander en vorm deur hul suksesvolle bereiking van hul doel: om funksionele atoomwapens te ontwikkel en te skep.

Die skeuring van die atoom

In die dertigerjare is ontdek dat die atoom verdeel kan word in wat bekend staan as die splitsingsproses. In 1939 sou talle Amerikaanse wetenskaplikes soek na maniere waarop hierdie proses vir militêre doeleindes ingespan kan word. Ironies genoeg was baie van die wetenskaplikes wat aan hierdie projek sou werk, nuut oorgeplante Europeërs wat uit fascistiese regimes in Europa ontsnap het. Hierdie wetenskaplikes het hul lewens nou toegewy aan die nederlaag van hierdie regimes.

Die vroeë stadiums van die projek

Die eerste groot stap in wat uiteindelik die Manhattan -projek sou word, was toe die wetenskaplike Enrico Fermi in 1939 met verteenwoordigers van die Departement van die Vloot sou vergader. Kort daarna in die somer van 1939 sou die legendariese denker Albert Einstein gevra word om 'n voorlegging aan die destydse president Franklin D. Roosevelt te lewer. In die voorlegging het Einstein getoon dat daar 'n enorme militêre potensiaal bestaan in die vrystelling van 'n totaal onbeheerbare splitsingskettingreaksie. Hierdie kettingreaksie kan effektief ingespan word om 'n wapen te skep soos nog nooit op die aarde gesien is nie.

Die heel eerste fase van die projek het vroeg in 1940 vooruitgegaan. Die oorspronklike begroting was 'n toekenning van $ 6,000 in navorsingsfinansiering. In die loop van byna twee jaar was die resultate belowend en het die kantoor van wetenskaplike navorsing en ontwikkeling op 6 Desember 1941 begin toesig hou oor die projek.

Die Verenigde State betree die Tweede Wêreldoorlog in 1941 en die navorsing rondom die (nogtans naamlose projek) sal na die departement van verdediging oorgeplaas word. (Toe genoem die oorlogsdepartement) Daarom word geglo dat die grootste vordering gemaak kan word as dieselfde professionele persone 'n direkte, praktiese benadering tot die ondersoek van wapens volg.

Die Manhattan -projek is gebore

Die Manhattan -projek sou uiteindelik sy amptelike kodenaam in 1942 ontvang. Dit was te danke aan 'n groot deel van die afvaardiging van 'n groot deel van die konstruksiewerk wat verband hou met die projek aan die Corps of Engineers -distrikskantoor in Manhattan. Een rede hiervoor is dat 'n groot deel van die vroeë navorsing vir die projek aan die Columbia University, wat in die Manhattan -gebied geleë was, was.

Een ding wat hierdie projek moet verstaan, is dat dit 'n groot projek was. Alhoewel baie werk in die Manhattan -omgewing uitgevoer is, was hierdie gedeelte van New York nie die enigste plek waar navorsing en ontwikkeling gedoen is nie. In werklikheid was daar navorsingskantore in die hele Verenigde State van Amerika wat verskillende take hanteer en in waters instap wat nog nooit deur wetenskaplike en militêre personeel ingeloop is nie.

'N Internasionale projek

Die Verenigde State was nie die enigste land wat by so 'n projek betrokke was nie. Duitsland het sy eie in 1940 begin, en dit sou 'n understatement wees om te sê dat dit die grootste kommer vir die Verenigde State en Groot -Brittanje was. Groot -Brittanje was ook aan die werk aan sy eie projek en sou uiteindelik in 'n gesamentlike ooreenkoms met die Verenigde State en Kanada saamwerk om die Manhattan -projek te help ontwikkel.

In 1943 sal sommige van die grootste wetenskaplike verstand ter wêreld hul werk bydra tot die Manhattan -projek, wat help om die vordering daarvan voort te sit.

Die skepping van die splitsingsketting

Een van die belangrikste aspekte van navorsing was om geskikte bronmateriaal te vind vir die skepping van die splitsingsketting. Uranium 238 is oorspronklik geëksperimenteer, maar die resultate was tevergeefs. Uraan 235 het die volgende materiaal geword wat aan splitsingskettingprosesse onderwerp is, maar dit was eenvoudig nie betroubaar genoeg nie en te veel werk was nodig om duidelike resultate te kry. Uiteindelik was dit Plutonium 235 wat die bronverbinding sou wees wat gebruik sou word om die kettingreaksie te skep.

Die konsep van die bom

Voor 1943 is daar nie baie moeite gedoen met die ontwikkeling van die bom wat gebruik sou word om die splitsingsketting in 'n wapen te verander nie. Aangesien beperkte vordering gemaak is met die splitsing van die atoom, sou die pad na die werklike skepping van die bom teen topsnelheid beweeg toe J. Robert Oppenheimer 'n laboratorium in Los Alamos, New Mexico, opstel om te werk aan die skep en toets van 'n werklike bom.

Die omvang van die Manhattan -projek in New Mexico was om die hoeveelheid splitsbare materiaal wat nog genoeg sou wees om die kritieke massa van 'n ontploffing te verminder, te verminder. Dit was benewens die moontlikheid om die kettingreaksie binne 'n bom te benut wat betroubaar en effektief kon reageer wanneer dit ontplof word.

Die eerste atoombom toets

Na $ 2 miljard dollar se navorsing en ontwikkeling, is 'n werkbare prototipe van 'n atoombom gemaak. Gedurende die vroeë oggendure van 16 Julie 1945 het die New Mexico -woestyn die eerste atoombomtoets geword. Die bom het ontplof in die vorm van 'n massiewe sampioenwolk. Die krag van die ontploffing was gelykstaande aan 20 000 ton dinamiet en die skokgolwe is kilometers ver gevoel. 'N Groot deel van die omliggende toetsarea vir die bom is verdamp. Dit was duidelik dat die nuwe superwapen gewerk het en die tyd en geld wat aan die Manhattan -projek bestee is, het die gewenste resultate gelewer. Die resultate was die skepping van die mees vernietigende wapen in die geskiedenis van die mens tot op daardie tydstip.

Kort daarna sou die atoombom gebruik word om die Tweede Wêreldoorlog te beëindig deur die bombardemente van Hiroshima en Nagasaki.

51f. Die Manhattan -projek

Hierdie eens geklassifiseerde foto bevat die eerste atoombom en 'n wapen wat atoomwetenskaplikes 'Gadget' genoem het. Die kerntydperk het op 16 Julie 1945 begin toe dit in die New Mexico -woestyn ontplof het.

Vroeg in 1939 het die wêreld se wetenskaplike gemeenskap ontdek dat Duitse fisici die geheime van die skeuring van 'n uraanatoom geleer het. Vrees het vinnig versprei oor die moontlikheid dat Nazi -wetenskaplikes die energie gebruik om 'n bom te produseer wat onuitspreeklike vernietiging kan veroorsaak.

Wetenskaplikes Albert Einstein, wat uit Nazi -vervolging gevlug het, en Enrico Fermi, wat uit Fascistiese Italië ontsnap het, woon nou in die Verenigde State. Hulle was dit eens dat die president ingelig moet word oor die gevare van atomiese tegnologie in die hande van die asmagte. Fermi het in Maart na Washington gereis om sy kommer aan regeringsamptenare te kenne te gee. Maar min het sy ongemak gedeel.

Niks aan die toeval oorgelaat nie, het atoomwetenskaplikes in Los Alamos in Mei 1945 'n voortoets gedoen om die moniteringsinstrumente na te gaan. 'N Bom van 100 ton is ongeveer 800 meter van die Trinity-plek ontplof waar Gadget 'n paar weke later ontplof sou word.

Einstein het 'n brief aan president Roosevelt geskryf waarin hy aanspraak maak op die ontwikkeling van 'n atomiese navorsingsprogram later daardie jaar. Roosevelt het nie die noodsaaklikheid of die nut van so 'n projek gesien nie, maar het ingestem om stadig voort te gaan. Aan die einde van 1941 het die Amerikaanse poging om 'n atoombom te ontwerp en te bou sy kodenaam gekry en die Manhattan -projek gekry.

Die navorsing was eers gebaseer op slegs 'n paar universiteite en die Columbia University, die Universiteit van Chicago en die Universiteit van Kalifornië in Berkeley. In Desember 1942 het 'n deurbraak plaasgevind toe Fermi 'n groep fisici gelei het om die eerste beheerde kernkettingreaksie onder die tribune van Stagg Field aan die Universiteit van Chicago te produseer.

Enrico Fermi, 'n fisikus wat die fascistiese Italië na Amerika verlaat het, het die VSA aangemoedig om met atoomnavorsing te begin. Die resultaat was die uiters geheime "Manhattan-projek".

Na hierdie mylpaal is die fondse meer vrylik toegewys en die projek vorder vinnig. Kernfasiliteite is gebou in Oak Ridge, Tennessee en Hanford, Washington. Die belangrikste monteeraanleg is in Los Alamos, New Mexico, gebou. Robert Oppenheimer was verantwoordelik vir die samestelling van die stukke by Los Alamos. Nadat die finale rekening opgeneem is, is byna $ 2 miljard bestee aan navorsing en ontwikkeling van die atoombom. Die Manhattan -projek het meer as 120 000 Amerikaners in diens gehad.

Geheimhouding was uiters belangrik. Nie die Duitsers of die Japannese kon van die projek verneem nie. Roosevelt en Churchill was ook dit eens dat Stalin in die duister gehou sou word. Gevolglik was daar geen openbare bewustheid of debat nie. Dit is onmoontlik om 120 000 mense stil te hou, daarom het slegs 'n klein bevoorregte kader van innerlike wetenskaplikes en amptenare geweet van die atoombom se ontwikkeling. Trouens, vise-president Truman het nog nooit van die Manhattan-projek gehoor totdat hy president Truman geword het nie.

Alhoewel die as -magte nie bewus was van die pogings by Los Alamos nie, het Amerikaanse leiers later verneem dat 'n Sowjet -spioen met die naam Klaus Fuchs die binnekring van wetenskaplikes binnegedring het.

Hierdie krater in die Nevada -woestyn is geskep deur 'n kernbom van 104 kiloton wat 635 voet onder die oppervlak begrawe is. Dit is die resultaat van 'n toets van 1962 wat ondersoek het of kernwapens gebruik kan word om kanale en hawens uit te grawe.

Teen die somer van 1945 was Oppenheimer gereed om die eerste bom te toets. Op 16 Julie 1945, op Trinity Site naby Alamogordo, New Mexico, het wetenskaplikes van die Manhattan -projek hulle gereed gemaak om die ontploffing van die eerste atoombom ter wêreld te sien. Die toestel is op 'n toring van 100 voet aangebring en net voor dagbreek ontslaan. Niemand was behoorlik voorbereid op die uitslag nie.

'N verblindende flits sigbaar vir 200 myl verlig die oggendhemel. 'N Swamwolk het 40 000 voet bereik en vensters van burgerlike huise tot 100 myl daarvandaan uitgeblaas. Toe die wolk na die aarde terugkeer, het dit 'n krater van 'n half kilometer wye gevorm wat sand verander het in glas. 'N Vals toesmeerverhaal is vinnig vrygestel en verduidelik dat 'n groot ammunisie-storting net in die woestyn ontplof het. Gou het president Truman in Potsdam, Duitsland, die boodskap gekry dat die projek suksesvol was.

Effekte van die Manhattan -projek wat vorentoe gaan

Die bombardemente op Hiroshima en Nagasaki was nie die einde van navorsing oor en die daaropvolgende ontwikkeling van nog sterker atoomwapens nie. Vandag het moderne kernbomme 80 keer die sterkte van die bom wat op Hiroshima neergesit is. Die sampioenwolk wat oor Hiroshima geproduseer word, is kleiner as 1% van die moderne eweknie in vergelyking met die geraamde sampioenwolk van moderne atoombomme. Dit is 'n skrikwekkende gedagte aangesien letterlik net die ontploffing van een van hierdie moderne atoombomme die einde van byna alle lewe op aarde sou beteken.

Selfs nadat die eerste vernietiging deur hierdie bomme met die eerste oogopslag gesien is, het lande na die einde van die Tweede Wêreldoorlog slegs probeer om hul eie atoombomme te skep. 'N Kernwapenwedloop het tussen die groot spelers begin, en daar was 'n tyd van sulke onsekerheid tussen die Sowjetunie en die Verenigde State dat baie burgers van albei nasies elke aand gaan slaap het en gewonder het of hulle sou wakker word en die sonsopkoms sou sien meer tyd.

Die geskiedenis van 'n park toegewy aan die Manhattan -projekverhaal

Hierdie foto van 2016 toon 'n uitsig op die B Reactor National Historic Landmark van die Hanford -terrein, 'n lewendige toerisme- en opvoedkundige trekking wat deel uitmaak van die Manhattan Project National Historical Park.

Die Manhattan-projek was 'n ongekende, geheimsinnige navorsings- en ontwikkelingsprogram wat tydens die Tweede Wêreldoorlog geskep is om 'n atoomwapen te ontwikkel.

Die begin van die atoomtydperk word erken as een van die belangrikste gebeurtenisse van die 20ste eeu. Sy diepgaande nalatenskappe sluit in die verspreiding van kernwapens, groot omgewingsherstelwerk, die ontwikkeling van die nasionale laboratoriumstelsel en vreedsame gebruik van kernmateriaal soos kerngeneeskunde.

In 2001 werk DOE saam met die Advisory Council on Historic Preservation en 'n paneel gesiene historiese bewaringskundiges om bewaringsopsies te ontwikkel vir ses historiese fasiliteite van die Manhattan-projek uit die DOE-besit, wat die paneel van buitengewone historiese betekenis gehad het en 'herdenking' waardig was. as nasionale skatte. ”

In 2004 het die kongres die National Park Service (NPS) opdrag gegee om met DOE saam te werk om te evalueer of dit gepas en haalbaar is om 'n nuwe eenheid van die nasionale parkstelsel te vestig wat die verhaal van die Manhattan -projek vertel.

Na 'n dekade se werk deur plaaslike gemeenskappe, verkose amptenare, DOE, NPS en ander belanghebbendes, is die Manhattan Project National Historical Park goedgekeur as deel van die Carl Levin en Howard P. "Buck" McKeon National Defense Authorization Act for Fiscal Year 2015 Die park bevat geriewe op die drie primêre Manhattan Project -plekke - Los Alamos, Oak Ridge en Hanford.

By Los Alamos het meer as 6000 wetenskaplikes en ondersteuningspersoneel gewerk om die atoomwapens te ontwerp en te bou. Die park bevat tans drie gebiede: Gun Site, wat verband hou met die ontwerp van die "Little Boy" bom V-Site, wat gebruik is om komponente van die Trinity-toestel en Pajarito Site, wat gebruik is vir plutonium-chemiese navorsing, te monteer.

Die Clinton Engineer Works, wat die Oak Ridge -reservaat geword het, ondersteun drie parallelle industriële prosesse vir uraanverryking en eksperimentele plutoniumproduksie.

Die park bevat die X-10 Graphite Reactor National Historic Landmark, wat klein hoeveelhede plutonium geproduseer het ter ondersteuning van Los Alamos-wapenwerkgeboue by die Y-12-kompleks, die tuiste van die elektromagnetiese skeidingsproses vir uraanverryking en die plek van die K-25 gebou, waar tegnologie vir gasverspreiding van uraanverryking vooropgestel is.

Die Hanford Engineer Works, nou die Hanford -terrein, huisves meer as 51 000 werkers wat 'n massiewe nywerheidskompleks gebou en bedryf het om uraanbrandstof in reaktore te vervaardig, te toets en te bestraal en dan plutonium chemies te skei om in wapens gebruik te word.

Die Hanford-landskap is ook verteenwoordigend van een van die eerste dade van die Manhattan-projek-die veroordeling van private eiendom en die uitsetting van huiseienaars en Amerikaanse Indiese stamme om die weg te ruim vir die geheimsinnige werk. Die park bevat die B Reactor National Historic Landmark, wat die materiaal vir die Trinity Test en plutoniumbom vervaardig het en vier historiese geboue uit die begin van die eeu wat besoekers 'n blik op die geskiedenis van die Hanford-gebied gee voor die aankoms van Manhattan Projek.

Die park word bestuur as 'n samewerkende vennootskap tussen DOE, wat steeds die parkgeriewe besit, bewaar en onderhou en sal poog om openbare toegang tot hulle en NPS, wat die park bestuur, uit te brei, die verhaal van die Manhattan -projek te interpreteer en tegniese hulp aan DOE oor historiese bewaring. 'N Ooreenkoms memorandum tussen DOE en die Amerikaanse departement van binnelandse sake wat in November 2015 onderteken is, het die park amptelik geskep en lei die implementering van die parkmissie deur die twee agentskappe.

Terwyl 'n belangrike komponent van die nasionale historiese parkmissie binne DOE die toegang van die publiek tot die parkgeriewe verbeter, werk DOE en sy kontrakteurs ook daaraan om aanlynhulpbronne te ontwikkel, sodat virtuele besoekers en studente kan leer oor die historiese fasiliteite en die Manhattan -projek.

Hierdie DOE-webblad bied 'n wye verskeidenheid historiese bronne in druk, aanlyn en persoonlik in die Manhattan-projek. Die departement het ook podcasts oor die geskiedenis en impak van die Manhattan -projek vervaardig.

By die Los Alamos -parkeenheid bied die Bradbury Science Museum, bedryf deur Los Alamos National Laboratory, talle elektroniese hulpbronne, insluitend 'n oorsig van die park en Projek Y in Los Alamos, en 'n oorsig van Manhattan Project -terreine op laboratoriumgrond. Met die aanlyn versamelingsdatabasis van die Bradbury Science Museum kan besoekers artefakte, foto's en historiese dokumente van die Manhattan -projek deursoek. LANL het ook 'n video gemaak van historiese terreine en werk daaraan om dit vir toekomstige geslagte te bewaar.

Oak Ridge se K-25 virtuele museum bied besoekers inligting oor die Manhattan-projek en die koue oorlog.

Die Hanford -park -eenheid is toeganklik vir virtuele besoekers deur 'n verskeidenheid hulpbronne, insluitend dié wat deur vennote in die gemeenskap verskaf word. DOE bied virtuele toegang tot die B Reactor National Historic Landmark via 'n 360-grade kamerastelsel.

Die Hanford History Project (HHP) by Washington State University Tri Cities bewaar die federale Manhattan -projek van DOE en versameling artefakte en mondelinge geskiedenis van die Koue Oorlog. Virtuele toegang tot hierdie versamelings, sowel as die versamelings van mondelinge geskiedenis van die HHP, geskenkde argiefmateriaal, dokumente en foto's is beskikbaar op HHP se webwerf.

Die B Reactor Museum Association bied 'n reeks video's met diepgaande inligting oor hoe die B Reactor funksioneer en waarom dit erken word as 'n wetenskaplike en ingenieurswonder.

Vroulike wetenskaplikes van die Manhattan -projek

Dr Marie Curie

Marie Sklodowska is in 1867 in Warskou, Pole, gebore as 'n wiskunde- en fisika -onderwyser.
Omdat sy nie 'n universiteit kon bywoon nie, omdat sy 'n vrou was, het sy 'n ondergrondse kollege by die "Flying University" bygewoon.
Marie verhuis in 1891 na Parys om 'n graad in fisika en wiskunde te volg.
Nadat sy haar meestersgraad ontvang het, het Marie begin werk saam met Pierre Curie, wat later haar man geword het.
Marie en Pierre Curie het twee nuwe elemente, polonium en radium, ontdek en die term radioaktiwiteit geskep.
In 1903 word Marie Curie die eerste vrou wat haar doktorsgraad in Frankryk verwerf het.
Marie en Pierre ontvang die Nobelprys vir hul werk in fisika in 1903.
In 1911 ontvang Marie Curie die Nobelprys vir Chemie.
Gedurende die Eerste Wêreldoorlog het Curie haar tyd daaraan gewy om gewonde soldate te help en oorlogsverbande met haar Nobelprysgeld gekoop.

Dr Lise Meitner

Lise Meitner is in 1878 in 'n Joodse gesin in Oostenryk gebore.
Meitner het in 1905 die tweede vrou geword wat 'n doktorsgraad in fisika aan die Universiteit van Wene verwerf het.
Na die gradeplegtigheid verhuis Meitner na Berlyn en begin saam met Otto Hahn werk waar hulle verskeie nuwe isotope ontdek.
In 1922 word Meitner die eerste vrou in Duitsland wat 'n professor in fisika aan die Universiteit van Berlyn geword het.
In 1938 moes Meitner in die geheim uit Berlyn na Swede reis, waar sy haar werk sou voortsit.
Ses maande later publiseer Meitner en Otto Frisch resultate waarin kernsplitsing verduidelik en genoem word.
Alhoewel Lise verskeie kere genomineer is, het Lise nie die Nobelprys vir haar werk ontvang nie. Otto Hahn het die toekenning ontvang.
Meitner, wat 'n pos op die Manhattan -projek aangebied het, het die werk geweier en gesê: "Ek het niks met 'n bom te doen nie."
Element 109, wat in 1997 ontdek is, is ter ere van haar genoem. Meitnerium.

Dr Leona Woods Marshall Libby

Leona studeer op 14 -jarige ouderdom en op 19 -jarige ouderdom aan die Universiteit van Chicago met 'n BS in chemie.
Terwyl sy haar Ph.D. Woods is aangestel om te werk op die Chicago -stapel, waar sy die neutrondetektore gebou het om die vloei van vloei op neutrone in die stapel te meet.
Leona was ook die enigste vroulike wetenskaplike op die Hanford -werf en werk direk saam met Enrico Fermi.
Dr Libby het 'n suksesvolle loopbaanonderrig aan verskeie universiteite gehad voordat hy in 1973 'n pos by UCLA as besoekende professor aangeneem het.
Dr Libby se navorsing het die studie van reënvalpatrone in boomringe ingesluit honderde jare voordat rekords gehou is. Dit het die deur oopgemaak vir navorsing oor klimaatsverandering.

Die werk van die Manhattan -projek

In the initial stages of the American fission effort (1939-1942), scientists at a variety of university laboratories — notably Columbia University, the University of Chicago, and the University of California–Berkeley, among many others— identified key processes for the development of the “fissile material” fuel that is necessary for a nuclear weapon to operate.

The first approach considered was the isotopic enrichment of uranium. (Chemical elements can vary in the number of neutrons in their nucleus, and these different forms are known as isotopes.) It was discovered as early as 1939 that only one isotope of uranium was fissionable by neutrons of all energies, and by 1941 it was understood that to make a fission weapon required a reasonably pure amount of material that met this criterion. Less than 1% of the uranium as mined is the fissile uranium-235 isotope, with the other 99% being uranium-238, which inhibits nuclear chain reactions. It was understood by 1941 that to make a weapon the fissile uranium-235 would need to be separated from the non-fissile uranium-238, and that because they were chemically identical this could only be accomplished through physical means that relied on the small (three neutron) mass difference between the atoms. Isotopic separation had been undertaken for other elements (for example, the separation of the hydrogen isotope deuterium from the bulk of natural water), but never on a scale of the sort contemplated for the separation of uranium. 16

Several methods were proposed and explored at small scales at various research sites in the United States. The preferred candidates by the end of the first year of the Manhattan Project (1942) were:

Electromagnetic separation, in which powerful magnetic fields were used to create looping streams of uranium ions that would slightly concentrate the lighter isotope at the fringes. This work was related to the cyclotron concept pioneered by Ernest Lawrence at the University of California, and the bulk of the research took place at his Radiation Laboratory.

Gaseous diffusion, in which a gaseous form of uranium was forced through a porous barrier consisting of extremely fine passageways. The gas molecules containing the lighter isotope would navigate the barrier slightly faster than the gas molecules containing the heavier isotope, although the effect would have to be magnified through many stages before it resulted in significant separation. This work was originally explored primarily at Columbia University under the guidance of Harold Urey and others.

Thermal diffusion, in which extreme heat and cold were applied to opposite sides of a long column of uranium gas, which also resulted in slight separation, with the lighter uranium isotope concentrating at one end. This was initially investigated by Philip Abelson at the Naval Research Laboratory.

Centrifugal enrichment, in which the rapid spinning of a uranium gas allowed for the slight concentration of the lighter element at the center of the whirling mixture, a process that would also require a large number of “stages” to be successful. This was pursued by physicist Jesse W. Beams at the University of Virginia and at the Standard Oil Development Company in New Jersey. 17

Over the course of 1943, centrifugal enrichment proved less promising than the other methods, and by 1944 the method was essentially abandoned (though it would, in the postwar period, be perfected by German and Austrian scientists working in the Soviet Union). Because it was unclear which of the other techniques would be most successful at scale, both the electromagnetic and gaseous diffusion methods were pursued with great gusto, and arguably constituted the most substantial portion of the Manhattan Project. The construction and operation of the two massive facilities required for these methods (the Y-12 facility for the electromagnetic method, and K-25 facility for the gaseous diffusion method) alone made up 52% of the cost of the overall project, and all of the Oak Ridge facilities together totaled 63% of the entire project cost. While thermal diffusion was initially imagined as a competitor process, difficulties in achieving the desired level of enrichment led to all three methods being “chained” together as a sequence: the raw uranium would be enriched from the natural level of 0.72% uranium-235 to 0.86% at the thermal diffusion plant, and its output would then be enriched to 23% at the gaseous diffusion plant, and then finally enriched to an average level of 84% at the electromagnetic plants. 18

Image 3: Calutron operators at the Y-12 plant in Oak Ridge monitored indicators and turned dials in response to changing values, not knowing that they were actually aiming streams of uranium ions, much less that they were producing the fuel for a new weapon. Source: Photo by Ed Westcott, 1944 (Department of Energy).

The plants for the production of enriched uranium were constructed in Oak Ridge, Tennessee, an isolated site that was chosen primarily for its proximity to the large electrical resources provided by the Tennessee Valley Authority. The Oak Ridge site (Site X) employed over 45,000 people for construction at its peak, and had a similar number of employees on the payroll for managing its continued operations once built. A “secret city,” the facility relied on heavy compartmentalization (“need to know”) so that practically none of its thousands of employees had any real knowledge of what they were producing. Every aspect of life in Oak Ridge was controlled by contractors and the military, in the aim of producing weapons-grade material in maximum haste and with a minimum of security breaches. Situated in the Jim Crow South, the facility was entirely segregated by law, and living conditions between African-Americans and whites varied dramatically. Various industrial contractors managed the different plants (for example, the Union Carbide and Carbon Corporation operated K-25, and the Tennessee Eastman Corporation operated Y-12). 19

In the process of researching the possibility of nuclear fission, another road to a bomb had made itself clear. Nuclear reactors had been contemplated as early as nuclear weapons. Where a nuclear weapon requires high concentrations of fissile material to function, a reactor does not: a controlled nuclear reaction (as opposed to an explosive one) can be developed through natural or slightly-enriched uranium through the use of a substance called a “moderator,” which slows the neutrons released from fission reactions. Under the right conditions, this allows a chain reaction to proceed even in unenriched material, and the reaction is considerably slower, and much more controllable, than the kind of reaction that occurs inside of a bomb.

Nuclear reactors had been explored as possible energy sources, though engineering difficulties would make this use of them more difficult than was anticipated (the first nuclear reactors for power purposes in the United States did not go critical until 1958). More importantly for the wartime planners, it was realized that the plentiful uranium-238 isotope, while not fissile, could still be quite useful. When uranium-238 absorbs a neutron, it does not undergo fission, but instead transmutes into uranium-239. Uranium-239, however, is unstable, and through a series of nuclear decays becomes, in the span of a few days, the artificial element plutonium-239. Isolated for the first time in February 1941, plutonium was calculated and confirmed to have very favorable nuclear properties (it is even more reactive than uranium-235, and thus even less of it is necessary for a chain reaction). 20

Image 4: Men working on the front face of the Hanford B-Reactor, circa 1944. Source: Department of Energy.

The first controlled nuclear reaction was achieved in December 1942 at the University of Chicago, by a team led by Enrico Fermi. The first reactor, Chicago Pile-1, used purified graphite as its moderator and 47 tons of natural (unenriched) uranium in the form of metal ingots. Even while the pilot Chicago Pile-1 reactor was still being constructed, plans were being made for the creation of considerably larger, industrial-sized nuclear reactors at a remote site in Hanford, Washington, constructed and operated by E.I. du Pont Nemours & Co. (DuPont). The Hanford site (Site W) was chosen largely for its proximity to the Columbia River, whose water would be used for cooling purposes. On dusty land near the river, three large graphite-moderated reactors were constructed starting in 1943, with the first reactor going critical in September 1944. A massive chemical facility known as a “canyon” was constructed nearby, by which, largely through automation and remote control, the irradiated fuel of the reactors was chemically stripped of its plutonium. This process involved dangerously radioactive materials, chemically noxious substances (powerful acids), and was fairly inefficient (every ton of uranium fuel that was processed yielded 225 grams of plutonium). 21

The labor conditions at Hanford varied considerably from Oak Ridge. Where Oak Ridge was imagined as a cohesive community, Hanford was not, and employed an abundance of cheap labor in far inferior work conditions (and those at Oak Ridge were not so great to begin with). The radioactive and chemical wastes at the site were treated in an expedient, temporary fashion, with the idea that in the less-hurried future they would be more properly eliminated. Subsequent administrations continued this approach for decades. Hanford became regarded as the most radioactively contaminated site in the United States, and since the end of the Cold War has been involved in expensive cleanup and remediation efforts. The Hanford project constituted about 21% of the total cost of the Manhattan Project. 22

Image 5: The relative costs (in 1945 USD) of the major expense categories of the Manhattan Project. Note that Oak Ridge has been broken down into its subcomponents (K-25, Y-12, S-50, etc.). Source: Data from Hewlett and Anderson 1962, Appendix 2, graph by Alex Wellerstein.

The work of these two sites — Oak Ridge and Hanford — constituted the vast bulk of the labor and expense of the Manhattan Project (roughly 80% of both). Without fuel, there could be no atomic bomb: it was and remains a key chokepoint in the development of nuclear weapons. As a result, it is important to conceptualize the Manhattan Project as much more than just basic science alone: without an all-out military-industrial effort, the United States would not have had an atomic bomb by the end of World War II.

The head of the Manhattan Project’s entire operation was Brigadier General Leslie R. Groves, a West-Point trained engineer who had previously been instrumental in the construction of the Pentagon building. Groves had accepted the assignment reluctantly, liking neither the risk of failure nor the fact that it was a home-front assignment. But once he accepted the job, he was determined to see it through to success. His unrelenting drive resulted in the Manhattan Project being given the top level of priority of all wartime projects in the United States, which allowed him nearly unfettered access to the resources and labor necessary to build a new atomic empire. Groves amplified the degree of secrecy surrounding the project through his application of compartmentalization (which he considered “the very heart of security”), and his own autonomous domestic and even foreign intelligence and counter-intelligence operations, making the Manhattan Project a virtual government agency of its own. (Despite these precautions, the project was, it later was discovered, compromised to the Soviet Union by several well-placed spies.) While it is uncharacteristic to associate the success or failure of massive projects with single individuals, it has been plausibly argued that Groves was perhaps the most “indispensable” individual to the project’s success, and that his willingness to accelerate and amplify the work being done in the face of setbacks, and to bully his way through military and civilian resistance, was essential to the project achieving its results when it did. 23

Though the scientific research on the project was initially dispersed among several American universities, as the work moved further into the production phase civilian and military advisors to the project concurred that the most sensitive research work, specifically that on the design of the bomb itself, should be located somewhere more secure than a university campus in a major city. Bush, Conant, and Arthur Compton had all come to the conclusion that a separate, isolated laboratory should be created for this final phase of the work. In late 1942, Groves identified Berkeley theoretical physicist J. Robert Oppenheimer as his preferred candidate for leading the as-yet-created laboratory, and on Oppenheimer’s recommendation identified a remote boys’ school in Los Alamos, New Mexico, as the location for the work. Initially imagined to be fairly small, the Los Alamos laboratory (Site Y) soon became a sprawling operation that took on a wide variety of research projects in the service of developing the atomic bomb, ending the war with over 2,500 people working at the site. 24

Image 6: The percentage distribution of personnel between divisions at Los Alamos. The reorganization in August 1944 merged several divisions into interdisciplinary groups focused around specific problems. The pre-reorganization division abbreviations: Chem = Chemistry, Eng = Engineering, Ex = Experimental Physics, Theo = Theoretical Physics,. The post-reorganization abbreviations: A = Administrative, CM = Chemistry & Metallurgy, F = Fermi (whose division studied many issues), G = Gadget, O = Ordnance, R = Research, Tr & A = Trinity and Alberta (Testing and Delivery), X = Explosives. Source: Hawkins 1983, 302.

Though the work of the bomb was even at the time most associated with physicists, it is worth noting that at Los Alamos, there were roughly equal numbers of physicists, chemists, metallurgists, and engineers. The physics-centric narrative, promulgated in part by the physicists themselves after the war (in part because the physics of the atomic bomb was easier to declassify than other aspects), obscures the multidisciplinary research work that was required to turn table-top laboratory science into a working weapon. 25

It is not exceptionally hyperbolic to say that the Los Alamos laboratory brought together the greatest concentration of scientific luminaries working on a single project that the world had ever seen. It was also highly international in its composition, with a significant number of the top-tier scientists having been refugees from war-torn Europe. This included a significant British delegation of scientists, part of an Anglo-American alliance negotiated by Winston Churchill and Roosevelt. For the scientists who went to the laboratory, especially the junior scientists who were able to work and mingle with their heroes, the endeavor took on the air of a focused and intensive scientific summer camp, and the numerous memoirs about the period at times underemphasize that the goal was to produce weapons of mass destruction for military purposes. 26

Los Alamos grew because the difficulty and scope of the work grew. Notably a key setback motivated a massive reorganization of the laboratory in the summer of 1944, when it was found that plutonium produced by nuclear reactors (as opposed to the small samples of plutonium that had been produced in particle accelerators) could not be easily used in a weapon. The original plan for an atomic bomb design was relatively simple: two pieces of fissile material would be brought together rapidly as a “critical mass” (the amount of material necessary to sustain an uncontrolled chain reaction) by simply shooting one piece into the other through a gun barrel using conventional explosives. This “gun-type” design still involved significant engineering considerations, but compared to the rest of the difficulties of the project it was considered relatively straightforward. 27

The first reactor-bred samples of plutonium, however, led to the realization that the new element could not be used in such a configuration. The presence of a contaminating isotope (plutonium-240) increased the background neutron rate of reactor-bred plutonium to levels that would pre-detonate the weapon were two pieces of material to be shot together, leading to a significantly reduced explosion (designated a “fizzle”). Only a much faster method of achieving a critical mass could be used. A promising, though ambitious, method had been previously proposed, known as “implosion.” This required the creation of specialized “lenses” of high explosives, arranged as a sphere around a subcritical ball of plutonium, that upon simultaneous detonation would symmetrically squeeze the fuel to over twice its original density. If executed correctly, this increase in density would mean that the plutonium in question would have achieved a critical mass and also explode. But the degree of simultaneity necessary to compress a bare sphere of metal symmetrically is incredibly high, a form of explosives engineering that had scarcely any precedent. Oppenheimer reorganized Los Alamos around the implosion problem, in a desperate attempt to render the plutonium method a worthwhile investment. Modeling the compressive forces, much less achieving them (and the levels of electrical simultaneity necessary) required yet another massive multidisciplinary effort. 28

As of summer 1944, there were two designs considered feasible: the “gun-type” bomb which relied upon enriched uranium from Oak Ridge, and the “implosion” bomb which relied upon separated plutonium from Hanford. The manufacture of the factories that produced this fuel required raw materials, equipment, and logistics from many dozens of sites, and together with the facilities that were involved with producing the other components of the bomb, there were several hundred discrete locations involved in the Manhattan Project itself, differing dramatically in size, location, and character. To choose a few interesting examples: a former playhouse in Dayton, Ohio, was converted into the site for the production of the highly-radioactive and highly-toxic substance polonium, which was to be used as a neutron source in the bombs, without any knowledge of the residents who lived around it most of the uranium for the project was procured from the Congo and a major reactor research site was created in Quebec, Canada, as part of the British contribution to the work. 29

Image 7: The assembled implosion “gadget” of the Trinity test, July 1945, with physicist Norris Bradbury for scale. Source: Los Alamos National Laboratory.

The uncertainties involved in the implosion design meant that the scientists were not confident that it would work and, if it did work, how efficient, and thus explosive, it would be. A full-scale test of the implosion design was decided upon, at a remote site at the White Sands Proving Ground, 60 miles from Alamogordo, New Mexico. On July 16, 1945, the test, dubbed “Trinity” by Oppenheimer, was even more successful than expected, exploding with the violence of 20,000 tons of TNT equivalent (20 kilotons, in the new standard of explosive power developed by the project participants). 30 (They had considerably more confidence in the gun-type bomb, and in any case, lacked enough enriched uranium to contemplate a test of it.)

Along with the work of the creation of the key materials for the bombs and the weapons designs themselves, additional thought was put into the question of “delivery,” the effort that would be required to detonate the bomb over a target. This aspect of the project, more a concern of engineering than science per se, was itself nontrivial: the atomic bombs were exceptionally heavy by the standards of the time, and the implosion bomb in particular had an ungainly egg-like shape. The “Silverplate” program created modified versions of the B-29 Superfortress long-range heavy bombers (most of their armaments and all of their armor were removed so that they could fly higher and faster with the heavy bombs), while Project Alberta, headquartered at Wendover Army Air Field in Utah, developed the ballistic cases of the weapons while training crews in the practice of delivering such weapons with relative accuracy. 31

Beginning in 1943, Project Y – the code name for Los Alamos during World War II – transformed the isolated Pajarito Plateau. The sounds of construction equipment replaced the voices of the Los Alamos Ranch School boys and local homesteaders. Construction crews hurriedly built many structures on mesa tops and in the canyons of Los Alamos. Countless concerns flooded Manhattan Project staff, but desiging structures to withstand the test of time was not one of them. The top-secret race to develop an atomic bomb before Nazi Germany was on and everyone felt the pressure.

Over the next 75 years, some of the structures slumped into disrepair from exposure to the harsh northern New Mexico environment — concrete cracking and spalling, wood frames rotting. That’s where Los Alamos National Laboratory’s historic preservation team enters the Manhattan Project story.

“Concrete has proven to be especially susceptible to the dozens of freeze-thaw cycles that often take place on a winter day in Los Alamos,” said Jeremy Brunette from the Laboratory’s Historic Building Surveillance and Maintenance Program.

The Manhattan Project National Historical Park team at Los Alamos identified several sites that need attention, and they work continuously to maintain, restore, and protect these historic sites. Most recently, two sites that share different stories from the early years of the Laboratory underwent preservation work.

Overshadowed story: plutonium recovery

A story that is often overshadowed when sharing Manhattan Project history is that of plutonium recovery. The Concrete Bowl helps bring that story to life.

Throughout the Manhattan Project, uranium and plutonium were so rare and costly that scientists carefully conserved every gram. By the end of 1945, it cost an estimated $390 million to create the plutonium for the Manhattan Project — that is over $5 billion in today’s money! During the Trinity Test, scientists planned to carry out a test with half the world’s plutonium, so tensions were understandably high.

If the Trinity Test did not succeed, project staff needed to recover the precious plutonium rather than losing it on a failed test. Manhattan Project researchers discussed several possible plutonium recovery approaches and tested any potential solutions that were not too far-fetched. One idea was the “water recovery method.”

For this method, staff members constructed a concrete bowl 200 feet in diameter and built a wooden water tank on a tower in the center. In this water tank, they placed a small-scale, industrial prototype of a bomb that contained natural uranium as a stand-in for plutonium. Researchers then detonated this mock-up with conventional explosives inside the water tank.

The water from the explosion landed in this concrete reservoir and drained into the bowl’s filter system, where workers recovered the metal fragments. Scientists continued these water-recovery tests until early 1945, but after realizing this method was not feasible for a full-scale nuclear test, they moved on to other potential recovery methods—including the infamous giant steel containment vessel known as “Jumbo.”

The Concrete Bowl remains in place today—an example of the wartime Laboratory’s practice of simultaneously testing different solutions to solve complex problems. In the 75 years since the bowl’s construction, weeds and trees took over and the local fauna discovered it as a reliable watering hole on the arid Pajarito Plateau.

“One of the pleasures of working at the Concrete Bowl is the amount of wildlife in the area. We saw elk, deer and coyotes every day,” Brunette said.

Concrete bowl before restoration. Concrete bowl after restoration.

Brunette also described that “in the Concrete Bowl, the steel reinforcing mesh was placed too close to the surface, exposing it to the elements and allowing it to carry moisture and rust into the concrete.”

Before any work began, the Lab’s Environmental Protection and Compliance Division ensured there was no contamination remaining from these early tests at the site. The Lab’s Historic Buildings team worked with Vital Consulting Group from Albuquerque on the removal of damaging vegetation to preserve this unique historic site. Vital Consulting Group also graded the soil away from the bowl to reduce the accumulation of water inside the bowl.

While the deer and elk may need to find a new watering hole, these efforts will preserve this historic site for years to come.

An early wartime test facility

From the beginning of Project Y, Robert Oppenheimer and Manhattan Project physicists believed they could make a “gun-type” atomic bomb, but they had to perfect the mechanism that could cause a sustained chain reaction in fissionable material. Manhattan Project researchers developed the Gun Site, known in 1943 as Anchor Ranch Proving Ground, to design and test nuclear weapon prototypes.

At this site, scientists, engineers, ordinance experts, and members of the U.S. Navy conducted experiments on the inner workings of this design. The name Gun Site refers to this site’s role in the development of the uranium weapon, Little Boy.

Because researchers fired numerous “gun-assembly” tests at this site using special gun barrels made by the U.S. Navy, they needed bunkers for protection during their experiments. Manhattan Project engineers constructed the buildings in a natural drainage, placing the tests above the bunkers and lessening the hazards of these experiments.

Scientists observed the tests from inside the concrete and earthen bunkers using a wooden periscope tower that relied on an elaborate system of mirrors—like a milk carton periscope you may have made as a child.

Gun Site during Manhattan Project—the wooden periscope tower is visible in the back right of the image.

Today, the preservation mission for this site came back to a familiar issue—concrete. Brunette explains why Manhattan Project era concrete presents the greatest preservation challenge. “We find that much of the Manhattan Project era concrete was mixed using large, smooth river rock aggregate that would not be suitable for modern construction.”

The buildings at Gun Site underwent extensive concrete repairs in 2012, including the reconstruction of the concrete parapet wall and a concrete cap to drain water from the top. However, that concrete cap failed and allowed further degradation of the historic site. The Lab and Vital Consulting Group worked to remove the crumbling concrete from the 2012 project. With this work completed, the Manhattan Project team will move forward with additional preservation efforts at Gun Site.

Gun Site parapet wall and cap before restoration. Gun Site parapet wall and cap after restoration.

These unique sites tell the story of Los Alamos National Laboratory’s history of solving difficult scientific and technological challenges and the story of a collective effort to achieve a common goal. The Manhattan Project was an immense project that created new fields of science and shaped the world we live in today.

In the spirit of its namesake, collaboration and teamwork defines the Manhattan Project National Historical Park. The National Park Service, the Department of Energy National Nuclear Security Administration’s Los Alamos Field Office, and Los Alamos National Laboratory work together to protect these sites for future generations. Ensuring that important historic sites remain intact to tell the story of this world-changing event is a crucial component of the collaborative effort to administer the Manhattan Project National Historical Park. The team is not finished they have already begun preservation work in another significant Manhattan Project historic location, V-Site.

The Manhattan Project National Historical Park

Preserving and sharing the nationally significant historic sites, stories, and legacies associated with the top-secret race to develop an atomic weapon during World War II.

This photo, taken on December 4, 1946, shows the center of Los Alamos as it looked during Project Y years. Called Technical Area 1, it was the core of the original laboratory.

Manhattan Project NHP-Los Alamos Public Engagement Specialist
Jonathan Creel
CPA-CPO
(505) 667-6277
Email

Manhattan Project NHP-Los Alamos Project Manager
Cheryl Abeyta
EPC-DO
Email

In 1943, as World War II raged across the globe, the United States government secretly constructed a laboratory on a group of isolated mesas in northern New Mexico. The top-secret Manhattan Project had a single military purpose—develop the world’s first atomic weapons.

The success of this unprecedented government program forever changed the world. Join us to discover the stories of the people behind the Manhattan Project and how they shaped the world we live in today.

Scientists, engineers, explosive experts, military personnel, and members of the Special Engineer Detachment all convened on the rural Pajarito Plateau in New Mexico for a secret project during World War II. Their mission: develop an atomic weapon before Nazi Germany. General Leslie R. Groves selected J. Robert Oppenheimer, a theoretical physicist from the University of California at Berkeley, as the scientific project director. This unprecedented undertaking required revolutionary science, engineering, technological innovation, and collaboration between civilians and military personnel from diverse backgrounds.

Twenty-eight months after Project Y began in Los Alamos, members of the Manhattan Project detonated the world’s first atomic weapon, the "Gadget," at the Trinity Site in southern New Mexico. After the military deployment of two atomic weapons on the Japanese cities of Hiroshima and Nagasaki, and the subsequent end of World War II, some Los Alamos scientists took their families and returned to their pre-war lives. Yet, many stayed to continue critical research in this new Nuclear Age.

Today, Los Alamos National Laboratory remains one of the United States’ premier science and technology institutions. Cutting-edge research and technological breakthroughs still happen here, as scientists and engineers work to solve some of today’s most complex problems.

The Manhattan Project’s legacy of revolutionary science and engineering, along with the lessons learned from that time, continues in the spirit of the modern Laboratory. Scientific and technological advances made in the pursuit of an atomic weapon contributed to progress in many areas: environmental and materials science, biology, nuclear medicine, nuclear energy, supercomputing, precision machining, even astronomy. This was also the beginning of the Department of Energy’s National Laboratory System.

The U.S. Congress directs the National Park Service and the Department of Energy to determine the significance, suitability, and feasibility of including signature facilities remaining from the Manhattan Project in a national historical park. This was an effort to preserve remaining structures in order to save them from being lost forever.

The National Defense Authorization Act, signed by President Obama, authorizes the creation of Manhattan Project National Historical Park. The stated the purpose of the park is “to improve the understanding of the Manhattan Project and the legacy of the Manhattan Project through interpretation of the historic resources.” On November 10, 2015, a Memorandum of Agreement signed by the Secretary of the Interior and the Secretary of the Department of Energy makes the park a reality.

Three sites tell the story of more than 600,000 Americans working to help end World War II. These three locations, integral to the Manhattan Project, comprise the park today.

designed and built the first atomic bombs. enriched uranium needed for the gun-type fission weapon. created plutonium for an implosion-type weapon design.

Today

The Manhattan Project National Historical Park encompasses 17 sites on Los Alamos National Laboratory property and 13 sites in downtown Los Alamos, where “Project Y” was centered during World War II. These sites represent the world-changing history of the Manhattan Project at Los Alamos.

Today, you can visit the Los Alamos Downtown historic sites, but the sites on Laboratory land are not accessible to the public. However, the Department of Energy, Los Alamos National Laboratory, and the National Park Service collaborate to provide public tours of three sites on Laboratory property. Click here for more information on these tours and how to register for them.