The Discovery of FissionThe Discovery of FissionThe Manhattan ProjectThe Manhattan Project

Pierre and Pierre and Marie CurieMarie Curie

Began work on the Began work on the new radioactivity.new radioactivity.

Discovered Radium Discovered Radium and Polonium.and Polonium.

Marie is the only Marie is the only person to win two person to win two Nobel Prizes in two Nobel Prizes in two different scientific different scientific fields.fields.

Enrico FermiEnrico Fermi

Bombarded almost Bombarded almost every element in the every element in the Periodic Table with Periodic Table with neutrons.neutrons.

Also missed fission.Also missed fission. Defected to the US Defected to the US

when he accepted when he accepted the Nobel Prize.the Nobel Prize.

E=mcE=mc22

As a result of the Theory of Relativity, As a result of the Theory of Relativity, 1905, Albert Einstein had proposed that 1905, Albert Einstein had proposed that matter could be converted to energy matter could be converted to energy and energy to matter.and energy to matter.

If this proved accurate, then the energy If this proved accurate, then the energy produced by the fission of one uranium produced by the fission of one uranium atom would be over 1000 times that atom would be over 1000 times that produce by burning one carbon atom.produce by burning one carbon atom.

Chain Reaction (?)Chain Reaction (?)

The following is an example of one of The following is an example of one of the many possible fission reactions.the many possible fission reactions.

Fission products are very radioactive Fission products are very radioactive as they have far too many neutrons in as they have far too many neutrons in their nuclei.their nuclei.

1100n + n + 235235

9292U U → → 1421425656Ba + Ba + 9191

3636Kr + 3 Kr + 3 1100nn

Niels BohrNiels Bohr Brought news of Brought news of

fission to the US at the fission to the US at the Fifth Washington Fifth Washington Conference on Conference on Theoretical Physics.Theoretical Physics.

Several researchers Several researchers went back to their labs went back to their labs and confirmed the and confirmed the work and reported work and reported back before the back before the conference was over.conference was over.

Leo Szilard Leo Szilard andand

Albert Albert EinsteinEinstein

Szilard Composed a letter to Franklin Szilard Composed a letter to Franklin Roosevelt.Roosevelt.

Einstein signed the letter dated Aug. 2, Einstein signed the letter dated Aug. 2, 1939.1939.

This letter leads ultimately to the This letter leads ultimately to the Manhattan Project which began in 1942.Manhattan Project which began in 1942.

Glenn SeaborgGlenn Seaborg

Discovered Discovered plutonium at U.C. plutonium at U.C. Berkeley, Feb. Berkeley, Feb. 23, 1941.23, 1941.

239239Pu also Pu also undergoes fission undergoes fission and is made from and is made from 238238U.U.

In 1939 German Scientists successful In 1939 German Scientists successful split an atom. split an atom.

Albert Einstein contacted FDR to Albert Einstein contacted FDR to “step up” research and development. “step up” research and development.

Manhattan ProjectManhattan Project

Got it’s name Got it’s name because the because the research started in research started in New YorkNew York

One of the best kept One of the best kept secrets of the war.secrets of the war.

Harry Truman did Harry Truman did not even know.not even know.

Robert Oppenheimer Robert Oppenheimer headed up the headed up the research team. research team.

General Leslie General Leslie GrovesGroves

Military Director Military Director of the Manhattan of the Manhattan Project.Project.

Famous for Famous for building the building the PentagonPentagon

Wanted to be a Wanted to be a field generalfield general

J. Robert J. Robert OppenheimerOppenheimer

Scientific Director of Scientific Director of the Manhattan the Manhattan Project.Project.

A physicist at UC A physicist at UC BerkeleyBerkeley

Dated a woman who Dated a woman who was a member of was a member of the communist party the communist party

Iowa State Iowa State CollegeCollege

Frank Spedding Frank Spedding Purified uranium Purified uranium metal.metal.

Over two million Over two million tons of uranium tons of uranium were produced in a were produced in a clapboard building clapboard building known as “Little known as “Little Ankeny”.Ankeny”.

University of University of ChicagoChicago

Enrico Fermi built the first nuclear Enrico Fermi built the first nuclear reactor, CP-1, in a squash court under reactor, CP-1, in a squash court under the football stadium. The first sustained the football stadium. The first sustained chain reaction occurred on Dec. 2, 1942.chain reaction occurred on Dec. 2, 1942.

Nuclear ReactorsNuclear Reactors

Fuel – fissionable material usually Fuel – fissionable material usually enriched enriched 235235U. CP-1 used uranium U. CP-1 used uranium metal from Iowa State.metal from Iowa State.

Moderator – slows down the neutrons Moderator – slows down the neutrons usually graphite, heavy water, or usually graphite, heavy water, or water. CP-1 used graphite.water. CP-1 used graphite.

Control Rods – absorb neutrons Control Rods – absorb neutrons usually boron or cadmium. CP-1 usually boron or cadmium. CP-1 used cadmium.used cadmium.

Oak RidgeOak Ridge

Secret City on the Clinch River near Secret City on the Clinch River near Knoxville, Tennessee.Knoxville, Tennessee.

Primary purpose was to enrich Primary purpose was to enrich 235235U.U. Also built a graphite reactor at X-10 Also built a graphite reactor at X-10

to study the production of plutonium.to study the production of plutonium.

X-10X-10

Oak Oak RidgeY-12RidgeY-12

Magnetic separation of Magnetic separation of 235235U from U from 238238U at Oak Ridge.U at Oak Ridge. The work was overseen by E. O. Lawrence from U. The work was overseen by E. O. Lawrence from U.

C. Berkeley.C. Berkeley.

Oak Oak Ridge K-Ridge K-

2525

Gaseous diffusion plant at Oak Ridge Gaseous diffusion plant at Oak Ridge for enrichment of for enrichment of 235235U.U.

Based on Graham’s Law of Effusion Based on Graham’s Law of Effusion and the oddity that UFand the oddity that UF66 is a gas. is a gas.

HanfordHanford

Secret City on the Columbia River in Secret City on the Columbia River in Washington State.Washington State.

A series of nuclear reactors designed A series of nuclear reactors designed to produce plutonium.to produce plutonium.

A chemical plant to purify plutonium.A chemical plant to purify plutonium.

Los Los AlamosAlamos

Secret City in the Sangre de Christo Secret City in the Sangre de Christo Mountains in New Mexico.Mountains in New Mexico.

The purpose was to design and build The purpose was to design and build the bombs.the bombs.

Tickling the Tickling the Tail of the Tail of the

DragonDragon

The exact size of The exact size of the critical mass the critical mass was determined by was determined by Otto Frisch at Los Otto Frisch at Los Alamos.Alamos.

Klaus FuchsKlaus Fuchs

Born in Germany and Born in Germany and came to Los Alamos as came to Los Alamos as part of the British part of the British MissionMission

Worked on the explosive Worked on the explosive lenslens

An ardent communist An ardent communist who leaked information who leaked information to the Russiansto the Russians

Gun Gun DesignDesign

This design worked with uranium.This design worked with uranium. A 2000 lb TNT Blockbuster bomb was A 2000 lb TNT Blockbuster bomb was

used as the “trigger”.used as the “trigger”.

Implosion Implosion DesignDesign

This design was required for plutonium.This design was required for plutonium. Impurities of Impurities of 240240Pu would release too many Pu would release too many

neutrons and cause premature detonation in neutrons and cause premature detonation in the gun design. This would lower the yield.the gun design. This would lower the yield.

Trinity SiteTrinity Site

The gun design was simple and the The gun design was simple and the scientists did not feel that testing scientists did not feel that testing was necessary.was necessary.

The implosion device was much more The implosion device was much more complicated and needed to be complicated and needed to be tested.tested.

The chosen site was in the Jornado The chosen site was in the Jornado del Muerto Valley near Alamogordo del Muerto Valley near Alamogordo New Mexico and code named Trinity.New Mexico and code named Trinity.

GadgetGadget

The Dawn of The Dawn of the Nuclear the Nuclear

AgeAge

The first nuclear The first nuclear explosion occurred explosion occurred at 5:29:45 am on at 5:29:45 am on July 16, 1945 at July 16, 1945 at Trinity.Trinity.

Edward Teller described wearing double Edward Teller described wearing double welders glasses and was not impressed until welders glasses and was not impressed until he removed his hands from around the he removed his hands from around the glasses.glasses.

Fermi was holding pieces of paper in his hand Fermi was holding pieces of paper in his hand and waited for the shock wave to estimate and waited for the shock wave to estimate the output. He later commented on missing the output. He later commented on missing both fission and the first nuclear explosion.both fission and the first nuclear explosion.

To Use or Not to UseTo Use or Not to Use With the end of the war in Europe on May With the end of the war in Europe on May

8, 1945, discussion began on whether or 8, 1945, discussion began on whether or not to use the bombs.not to use the bombs.

Japan had never been a threat to develop Japan had never been a threat to develop a bomb.a bomb.

Groves definitely wanted to use the Groves definitely wanted to use the bombs.bombs.

Szilard started a petition, signed by many Szilard started a petition, signed by many of the scientists involved in the project, to of the scientists involved in the project, to not drop the bombs. The petition was not drop the bombs. The petition was never delivered to Truman.never delivered to Truman.

509509thth Composite Composite

GroupGroup

B-29 Bomber Group was constituted and B-29 Bomber Group was constituted and refitted to carry the atomic bombs.refitted to carry the atomic bombs.

Special training took place stateside Special training took place stateside before transferring to Tinian Island.before transferring to Tinian Island.

The commander was Colonel Paul The commander was Colonel Paul TibbetsTibbets

Little Boy and Fat ManLittle Boy and Fat Man

HiroshimHiroshimaa

Aug. 6, 1945, Little Boy was dropped by Aug. 6, 1945, Little Boy was dropped by the Enola Gay piloted by Col. Paul Tibbets.the Enola Gay piloted by Col. Paul Tibbets.

Equivalent to 12-15 kilotons of TNT.Equivalent to 12-15 kilotons of TNT. 70,000 immediate deaths, 140,000 by the 70,000 immediate deaths, 140,000 by the

end of the year.end of the year.

NagasakiNagasaki

August 9, 1945, Fat Man was droped by August 9, 1945, Fat Man was droped by Bocks Car piloted by Maj. Charles Sweeney.Bocks Car piloted by Maj. Charles Sweeney.

Equivalent to 21 kilotons of TNT.Equivalent to 21 kilotons of TNT. 40,000 immediate deaths, 70,000 by the 40,000 immediate deaths, 70,000 by the

end of the year.end of the year.

VJ-DayVJ-Day

Japan surrenders Japan surrenders unconditionally unconditionally on Aug. 14, 1945.on Aug. 14, 1945.

Surrender signed Surrender signed in Tokyo Harbor in Tokyo Harbor aboard the USS aboard the USS Missouri on Sept. Missouri on Sept. 2.2.

The United States is the The United States is the only country to have used a only country to have used a nuclear weapon in anger.nuclear weapon in anger.

Fat Man and Mike Fat Man and Mike superimposedsuperimposed

over New York City over New York City

North Korea's latest nuclear weapons test is much more North Korea's latest nuclear weapons test is much more powerful than the previous two, according to estimates made powerful than the previous two, according to estimates made by instruments that measure seismic waves from the blast. by instruments that measure seismic waves from the blast. It's about the size of the bomb that devastated Hiroshima in It's about the size of the bomb that devastated Hiroshima in

World War II.World War II.

Bocks CarBocks Car

Enola GayEnola Gay