【英文原著类】theatomicbombingsof

THEATOMICBOMBINGSOFHIROSHIMAANDNAGASAKI1THEATOMICBOMBINGSOFHIROSHIMAANDNAGASAKIbyTheManhattanEngineerDistrictTHEATOMICBOMBINGSOFHIROSHIMAANDNAGASAKI2FOREWORDThisreportdescribestheeffectsoftheatomicbombswhichweredroppedontheJapanesecitiesofHiroshimaandNagasakionAugust6and9,1945,respectively.Itsummarizesalltheauthenticinformationthatisavailableondamagetostructures,injuriestopersonnel,moraleeffect,etc.,whichcanbereleasedatthistimewithoutprejudicingthesecurityoftheUnitedStates.ThisreporthasbeencompiledbytheManhattanEngineerDistrictoftheUnitedStatesArmyunderthedirectionofMajorGeneralLeslieR.Groves.Specialacknowledgementtothosewhoseworkcontributedlargelytothisreportismadeto:TheSpecialManhattanEngineerDistrictInvestigatingGroup,TheUnitedStatesStrategicBombingSurvey,TheBritishMissiontoJapan,andTheJointAtomicBombInvestigatingGroup(Medical).andparticularlytothefollowingindividuals:Col.StaffordL.Warren,MedicalCorps,UnitedStatesArmy,forhisevaluationofmedicaldata,Capt.HenryL.Barnett,MedicalCorps,UnitedStatesArmy,forhisevaluationofmedicaldata,Dr.R.Serber,forhiscommentsonflashburn,Dr.HansBethe,CornellUniversity,forhisinformationofthenatureofatomicexplosions,MajorsNolandVarleyandWalterC.Youngs,CorpsofEngineers,UnitedStatesArmy,fortheirevaluationofphysicaldamagetostructures,J.0.Hirschfelder,J.L.Magee,M.Hull,andS.T.Cohen,oftheLosAlamosLaboratory,fortheirdataonnuclearexplosions,Lieut.Col.DavidB.Parker,CorpsofEngineers,UnitedStatesArmy,foreditingthisreport.THEATOMICBOMBINGSOFHIROSHIMAANDNAGASAKI3INTRODUCTIONStatementbythePresidentoftheUnitedStates:SixteenhoursagoanAmericanairplanedroppedonebombonHiroshima,Japan,anddestroyeditsusefulnesstotheenemy.Thatbombhadmorepowerthan20,000tonsofT.N.T.IthadmorethantwothousandtimestheblastpoweroftheBritishGrandSlam,whichisthelargestbombeveryetusedinthehistoryofwarfare.ThesefatefulwordsofthePresidentonAugust6th,1945,markedthefirstpublicannouncementofthegreatestscientificachievementinhistory.Theatomicbomb,firsttestedinNewMexicoonJuly16,1945,hadjustbeenusedagainstamilitarytarget.OnAugust6th,1945,at8:15A.M.,Japanesetime,aB-29heavybomberflyingathighaltitudedroppedthefirstatomicbombonHiroshima.Morethan4squaremilesofthecitywereinstantlyandcompletelydevastated.66,000peoplewerekilled,and69,000injured.OnAugust9th,threedayslater,at11:02A.M.,anotherB-29droppedthesecondbombontheindustrialsectionofthecityofNagasaki,totallydestroying11/2squaremilesofthecity,killing39,000persons,andinjuring25,000more.OnAugust10,thedayaftertheatomicbombingofNagasaki,theJapanesegovernmentrequestedthatitbepermittedtosurrenderunderthetermsofthePotsdamdeclarationofJuly26thwhichithadpreviouslyignored.THEATOMICBOMBINGSOFHIROSHIMAANDNAGASAKI4THEMANHATTANPROJECTATOMICBOMBINVESTIGATINGGROUPOnAugust11th,1945,twodaysafterthebombingofNagasaki,amessagewasdispatchedfromMajorGeneralLeslieR.GrovestoBrigadierGeneralThomasF.Farrell,whowashisdeputyinatomicbombworkandwasrepresentinghiminoperationsinthePacific,directinghimtoorganizeaspecialManhattanProjectAtomicBombInvestigatingGroup.ThisGroupwastosecurescientific,technicalandmedicalintelligenceintheatomicbombfieldfromwithinJapanassoonaspossibleafterthecessationofhostilities.Themissionwastoconsistofthreegroups:1.GroupforHiroshima.2.GroupforNagasaki.3.GrouptosecureinformationconcerninggeneralJapaneseactivitiesinthefieldofatomicbombs.ThefirsttwogroupswereorganizedtoaccompanythefirstAmericantroopsintoHiroshimaandNagasaki.Theprimarypurposesofthemissionwereasfollows,inorderofimportance:1.Tomakecertainthatnounusualhazardswerepresentinthebombedcities.2.Tosecureallpossibleinformationconcerningtheeffectsofthebombs,bothusualandunusual,andparticularlywithregardtoradioactiveeffects,ifany,onthetargetsorelsewhere.GeneralGrovesfurtherstatedthatallavailablespecialistpersonnelandinstrumentswouldbesentfromtheUnitedStates,andthattheSupremeAlliedCommanderinthePacificwouldbeinformedabouttheorganizationofthemission.Onthesameday,11August,thespecialpersonnelwhoformedthepartoftheinvestigatinggrouptobesentfromtheUnitedStateswereselectedTHEATOMICBOMBINGSOFHIROSHIMAANDNAGASAKI5andorderedtoCaliforniawithinstructionstoproceedoverseasatoncetoaccomplishthepurposessetforthinthemessagetoGeneralFarrell.ThemainpartydepartedfromHamiltonField,Californiaonthemorningof13AugustandarrivedintheMarianason15August.On12AugusttheChiefofStaffsenttheTheaterCommanderthefollowingmessage:FORMACARTHUR,SIGNEDMARSHALL:GROVESHASORDEREDFARRELLATTINIANTOORGANIZEASCIENTIFICGROUPOFTHREESECTIONSFORPOTENTIALUSEINJAPANIFSUCHUSESHOULDBEDESIRED.THEFIRSTGROUPISFORHIROSHIMA,THESECONDFORNAGASAKI,ANDTHETHIRDFORTHEPURPOSEOFSECURINGINFORMATIONCONCERNINGGENERALJAPANESEACTIVITIESINTHEFIELDOFATOMICWEAPONS.THEGROUPSFORHIROSHIMAANDNAGASAKISHOULDENTERTHOSECITIESWITHTHEFIRSTAMERICANTROOPSINORDERTHATTHESETROOPSSHALLNOTBESUBJECTEDTOANYPOSSIBLETOXICEFFECTSALTHOUGHWEHAVENOREASONTOBELIEVETHATANYSUCHEFFECTSACTUALLYEXIST.FARRELLANDHISORGANIZATIONHAVEALLAVAILABLEINFORMATIONONTHISSUBJECT.GeneralFarrellarrivedinYokohamaon30August,withtheCommandingGeneralofthe8thArmy;ColonelWarren,w