The isotopes uranium-235 and plutonium-239 were selected by the atomic scientists because they readily undergo fission. Fission occurs when a neutron strikes the nucleus of either isotope, splitting the nucleus into fragments and releasing a tremendous amount of energy. The fission process becomes self-sustaining as neutrons produced by the splitting of atom strike nearby nuclei and produce more fission. This is known as a chain reaction and is what causes an atomic explosion.

In order to detonate an atomic weapon, you need a critical mass of fissionable material. This means you need enough U-235 or Pu-239 to ensure that neutrons released by fission will strike another nucleus, thus producing a chain reaction. The more fissionable material you have, the greater the odds that such an event will occur. Critical mass is defined as the amount of material at which a neutron produced by a fission process will, on average, create another fission event.

Little Boy and Fat Man utilized different elements and completely separate methods of construction in order to function as nuclear weapons. Little Boy detonated due to a fission chain reaction involving the isotope U-235 of uranium, while Fat Man used plutonium’s Pu-239 form.

 In order to avoid wasting time for U-235 to allow the atomic bomb to reach critical mass, General Leslie Groves consulted with lead scientists of the project and agreed to investigate simultaneously four separate methods of separating and purifying the uranium-235: gaseous diffusion, centrifuge, electromagnetic separation and liquid thermal diffusion.

Bomb Big Boy

Powered by plutonium, Fat Man could not use "artillery fire"methods such as Little boy did  in experiments at Hanford, WA. This was because threat of detonation. Hanford plutonium was considered less pure than plutonium extracted fromErnest O. Lawrence’s Berkeley Lab, containing isotope plutonium-240 than desired isotope of plutonium-239. Plutonium-240’s higher fission rate resticted the use of "artillery fire" would cause the atoms to undergo spontaneous fission before the gun-type design could bring two masses of plutonium together, which would lower the energy involved in the actual detonation of the bomb.

Thus, a new design was required. Physicist Seth Neddermeyer at Los Alamos constructed a design for the plutonium bomb that used conventional explosives around a central plutonium mass to quickly squeeze and consolidate the plutonium, increasing the pressure and density of the substance. An increased density allowed the plutonium to reach its critical mass, firing neutrons and allowing the fission chain reaction to proceed. To detonate the bomb, the explosives were ignited, releasing a shock wave that compressed the inner plutonium and led to its explosion.

information/ source:http://www.atomicheritage.org/mediawiki/index.php/The_Science_Behind_the_Atom_Bomb

--In the late 1890’s Antoine Henri Becquerel (1852-1908) discovered the radioactivity of uranium. 

--Radioactive elements emit radiant energy in the form of a (alpha), b (beta), g(gamma) rays.

--Following his discovery, in 1902 Marie Curie (1867-1934) and Pierre Curie (1859-1906) isolated the radioactive element radium. 

--Theory of Relativity by Albert Einstein (1879-1958)  states that small amounts of mass can be converted into very large amounts of energy.

--The equation E = mc², the speed of light, c, is very fast and a small amount of mass, m, can release large quantities of energy. Leading to discovery of nuclear fission.

--Niels Bohr (1885-1962) experimented with the atom and proposed structure, in 1913. Suggested atoms contained nucleus with orbiting electrons.

--Also states electrons orbit at certain distances from nucleolus and when changes atom emits radiation. Occurring in bursts.

--On September 12, 1932 Leo Szilard conceived of the possibility of a controlled release of atomic power through a multiplying neutron chain reaction. But also its use as a bomb.

--On July 4, 1934 Leo Szilard filed a patent application for the atomic bomb. Including key concept of the critical mass and using neutron for inducing chain reactions.

-- Ernest Rutherford (1871-1937) and Bohr discover isotopes of atoms in which were stable and unstable.

-- In 1932 James Chadwick introduces the neutron and added more understanding to the atom.

-- In 1934 Enrico Fermi  ,(1901-1954) ,  and Irene Joliot-Curie (1897-1956) discover first signs of nuclear fission by disengaging heavy atoms with spray of neutrons.

--Otto Hahn (1879-1968) a German physicist is credited with discovering fission repeating same experiments

--Based on Einsteins E=mc²theory when one atom is split it can release very great sums of energy.

--On October 8, 1935 Leo Szilard attempts to protect bomb form misuse. Calls out British War Office for protection under secrecy laws. It was rjected but later accepted in febbruary 1936 by British Admiralty. the British War Office rejected Szilard's offer, but a few months later in February 1936 he succeeded in getting the British Admiralty to accept the gift

--In 1938 Hahn discovered that the nucleus of uranium was broken down easily and produced a vast amount of energy

--Two subcritical masses of fissionable material would have to come together to form a supercritical mass for an explosion to occur.

--Predetonation was reduced by purification and " artillery fire" methods in which fissionable material was capable of reaching 3,000 feet per second.

--For plutonium the artillery method , shooting of one subliminal mass into another, would only work if complete purification of plutonium was achieved.

-- Unable to completely purify plutonium bomb designers turned toward the implosion method which at time was relatively unknown.

-- The implosion method detonated with symmetrical shockwaves in which directed inward compressing then releasing nuetrons from a subcritical mass of plutonium.

--The 1944 Nobel Prize in Chemistry went to Otto Hahn.

--Otto Frisch and Rudolph Peierls worked out the mechanics of a Uranium U-235 bomb at Cambridge. 

 They put Lise and her siblings into private education under the tutelage of a teacher trained in physics, Arthur Szarvassy.

Szarvassy as her first real teacher, she was granted entrance to the University of Vienna at 22 years old

Ludwig Boltzmann, best known for the Boltzmann Constant which relates the temperature of a particle to its level of energy,

Meitner would graduates with a doctorate in physics, second woman to graduate at the University of Vienna.

Stefan Meyer took over Boltzmann’s institute studying his own field — radioactivity. Studied the emission of now alpha particles.

Max Planck, because Meitner was the first woman the great scientist allowed to attend his lectures, within the year, she was his personal assistant. Through him that she can to meet Otto Hahn.

Discovered several new radioactive isotopes,formed the Hahn-Meitner research group. At own laboratory of Kaiser-Wilhelm Institute.

She received the Leibniz Medal from the Berlin Academy of Science for her discovery of a new, long-lived isotope of protactinum, and discovered the Augur Effect in 1917.

Induce Albert Einstein to call her the “German Marie Curie.”

She was forced to flee Berlin for Sweden when Germany annexed her home country of Austria.

Hahn meeting secretly with Meitner in Copenhagen — predictably, the topic of conversation was science

In 1939, this data was published. On nuclear fission by Meitner and Copenhagen.

First thought to apply Einstein’s famous equation, E= mc²,

Meitner not only saw the reason for the release of energy, but the capacity for that release to occur as part of a chain reaction.

Their work made Allied scientists to push Einstein to write the letter that convinced President Roosevelt to begin funding the Manhattan Project.

Meitner was offered a job on the project, but refused for she wanted no part in bomb.

The 1944 Nobel Prize in Chemistry went to Otto Hahn.

Otto Frisch and Rudolph Peierls worked out the mechanics of a Uranium U-235 bomb at Cambridge. 

In 1940 Starting in 1933, the laws in Germany removing Jews from Academic posts.

Similar pro-Ayran laws in other European countries had created a very large pool of academics and scientists.

sources/ information: http://www.atomicarchive.com/Bios/Meitner.shtml

He was given the task of convincing scientists and military commanders to support and join the "Manhattan Prodject". Scientist at fist had opposed working in new laboratory of Los Alamos because fear of military chain of command and ill decision making. When Robert F. Bather and Isidor I. Rabi of the Massachusetts Institute of Technology's Radiation Laboratory refused to join team they , together, wrote letter confirming that it was to remain civilian laboratory with presidential-like authority.

Beginning of Manhattan prodject . Oppenheimer spent the first three months of 1943 recruiting the most- qualified scientist from around the world he had even succeeded in signing on several at fist opposing scientists. It was generally accepted uranium yielded 2.2 secondary neutrons during fission but for plutonium only theoretical. Thus the early experimentation to find the maximum critical mass needed to invent the Atom bomb.

source/ information: http://www.atomicarchive.com/History/mp/p4s26.shtml

 the Manhattan Project secrecy regime was one that controlled every aspect of life and the people who lived during it. It was not any workplace procedure, because division between work and life was nonexistent at the sites. By the end of the war Groves and his staff had spent approximately $2.2 billion on production facilities, towns, and research in universitys from Tennessee, Washington, and New Mexico. Moving quickly was an necessity, investing hundreds of millions of dollars in unproven and hitherto unknown processes in secret and proved a great move. Secrecy made it possible to make decisions with little regard for normal peacetime political considerations. Many people working for the organization did not know what they were , working on until they heard about the bombing of Hiroshima on the radio.

During the prodject Oppenheimer and his students were sworn to secrecy. They had done well and little was released but in 1954 things had changed. Oppenheimer's legacy caught up to him during security hearing in which he effectively ended his government career. For people around him consequences were equal to worse. "Blacklisted" was the turn to for punishment. It entailed that all research was barred from whom was blacklisted and opportunity to leave country and start over. Jobs and even lives were put on the line in favor of secrecy. For the cause of a bomb that would take many away.

http://blog.nuclearsecrecy.com/2013/03/29/narratives-of-manhattan-project-secrecy/

Peter Newport Bragg Jr. 1920 - 1944 chemical engineer

While employed by the U. S. Navy Research Laboratory's "pilot-plant" at the Philadelphia Navy Yard. (Lab's was to perfect the thermal diffusion process of the enrichment of uranium). On Sept. 2, 1944 He was killed in a explosion in which sent radioactive uranium hexafluride over the Navy Yard. Their work was crucial to the development of the first atomic bomb.

Erwin Schrodinger (non Jew), Max Born, Otto Frisch, Hans Bethe, Rudolf Peirls, and Francis Simon, in which all were physicists; Otto Loewi, biochemist, who with Sir Henry Hallett Dale received the Nobel Prize for medicine in 1936.

Ernst Chain biochemist who received the Nobel Prize for medicine in 1945 with Howard Florey and Alexander Fleming.

Austrian born Thomas Gold,  ‘steady state’ theorist, Bondi, Fred Hoyle, Bondi and Fred Hoyle were  interned in 1940.

SPSL was active to have academics released and allow them to continue research of benefit to the war effort.

Such included‘Refugee scientists’ e.g. Max Born (1882-1970), the SPSL and Tess Simpson, and involvement with the atomic energy developments.

Otto Loewi (1873-1961), pharmacologist and physiologist, resettles in the United States.

sources/ information: http://blogs.royalsociety.org/history-of-science/2011/01/27/refugee-scientists/

-Information from spys significantly aided the speed of the Soviet atomic bomb project.

- Igor Kurchatov and Lavrenty Beria  checked other scientists progress through espionage information and close scientists published work. VENONO project intercepted soviet intelligence and decrypted reports sent during the war.

-Confirmation about espionage work came from the VENONA project, which intercepted and decrypted Soviet intelligence reports sent during and after World War II.

-Several spies at Los Alamos and elsewhere were identified through records from Soviet archives.

-Before World War II, the theoretical possibility for nuclear fission was highly discussed topic by top physicists in the world.

- Dwarfed by the scale of the Manhattan Project, contributions of the Soviet Union were rarely understood, and credited, outside of physics.

- It is estimated that $2 billion, eighty-six thousand tons of silver, and twenty-four thousand skilled workers drove the research and development phase of the project.

-The knowledge of techniques and strategies of the Allied programs that the Soviet Union intelligence received by means of espionage played a role in the rapid development of the Soviet bomb after the war.

-Lack of materials made it difficult to conduct research, and map out pathway for achieving the fuel they needed.

-Without espionage problems the Soviet atomic team problems would have taken many years to correct. Effecting the production of Soviet atomic weapon significantly.

sources/information: http://en.wikipedia.org/wiki/Atomic_spies

-About 1,000 families were affected by the condemnation order. 

-Originally  Kingston Demolition Range it was renamed Oak Ridge.

- A residential community for 13,000 was designed and built for project scientists and work-hands located on the slopes of Black Oak Ridge.

- Army presence at Oak Ridge simultaneously increased when Nicholas replaces Marshall as head of Manhattan Engineer District in August 1943. 

-One of his first tasks was to move the district headquarters to Oak Ridge.

-Well beyond initial plans Oak Ridge's population peaks at 75,000 in may 1945.

-In which 10,000 are employed by Roane-Anderson and 82,000 employed at the Clinton Engineer Works.

-gaseous diffusion plant known as K-25 was built and operated at Oak Ridge

Los Alamos

- Locating Project Y at Oak Ridge was considered, in location was not ideal.

-On Oppenheimer's recommendation vicinity of Albuquerque, New Mexico was considered ideal.

- Fears drowned out hopes in which the party then moved on to the vicinity of the Los Alamos Ranch School.

-View of the Sangre de Cristo Mountains ,in hope would inspire Project workers.

-Patterson approved site on 25 November 1942, authorizing $440,000 for the purchase of the site of 54,000 acres (22,000 ha),in which 8,900 acres (3,600 ha) was already owned by the Federal Government.

-Secretary of AgricultureClaude R. Wickard granted 45,100 acres (18,300 ha) of United States Forest Service land for Military use.

-Project Y by end of construction on November 30, 1943 well over seven million was spent.

- At first Los Alamos was to be a military laboratory. Oppenheimer and many other researchers had commissioned into the Army. 

-Groves and Oppenheimer then devise a compromise. The laboratory was to be operated by the University of California under contract to the War Department

Argonne

-Army-OSRD council on 25 June 1942 decided to build a pilot plant for plutonium production on 1,025 acres (415 ha), from the Cook County Forest Preserve District, in Red Gate Woods southwest of Chicago.

-Scale of operation proves to great decided to move initial plan to Oak Ridge and instead fund a research/ testing facility in Chicago.

-On 2 December 1942, led by Enrico Fermi a team initiated the first artificial, self-sustaining nuclear chain reaction in an experimental reactor known as Chicago Pile-1.

-Point at which reaction becomes self-sustaining is known as "going critical".

- January 1943 Major Arthur V. Peterson, orders Chicago Pile.

-1 to be moved to Red Gate Woods. Deemed to dangerous.

- After the war, Red Gate operation were moved to Argonne National Laboratory.

-Residents of the affected area (Hanford, White Bluffs, and Richland) given 90 day eviction notice.

- Residents compensated for appraisal of homes , not including crop or improvement, many were settled out of court.

-Wanapum lost access to their land and resettled in Priest Rapids.

-In 1943, health and environmental effects of different types and levels of radiation exposure was limited.  Tall stacks dispersed emissions and dilute the gases to safe levels of radioactivity. Monitored effects.

-Producing plutonium at Hanford involved three major operations—fuel fabrication, reactor operations, and chemical separation to extract the plutonium.

-Groves recruited DuPont in November 1942 to be the prime contractor for the construction of the plutonium production complex.

-DuPoint andWalter S. Carpenter, Jr. wanted no profit or patent to the work.

-Instead only a one dollar fee for legal reasons was acepted. Terminating contract early he was fined 33 cents

-Matthias designated Hanford Site Richland, Washington, was "ideal in virtually all respects".

- Isolated by and near  Columbia River, which could supply water to cool the reactors producing the plutonium.

- "Site W"

- Allocated $5 million for the acquisition of 40,000 acres (16,000 ha) of land in the area.

- In April 1943 start of Hanford ,an estimated 25,000 workers, half of whom were expected to live on-site.

-July 1944, some 1,200 buildings nearly 51,000 people were living in the construction camps.

- At its peak, the construction camp was the third most populous town in Washington state.

 -Like Los Alamos and Oak Ridge, Richland was a gated community with restricted access.

-B Reactor at Hanford built and operated by DuPont and was the world's first production-scale nuclear reactor. 

-B Reactor was the first of three plutonium reactors constructed in the 100 area during the Manhattan Project.

- Design based on Enrico Fermi’s “Chicago Pile I” of December 1942 and a pilot plant, the X-10 graphite reactor, in Oak Ridge, TN that began produced plutonium in November 1943.

-B Reactor designed to produce 250 million watts, a million times more than Chicago Pile I. 

-B reactor was water cooled.

-After 100 days in the reactor, a fuel element is removed and dropped into 20 feet of water to cool for 90 days then shipped to chemical separation plant (Area 200).

- Operators had to constantly monitor more than 5,000 instruments.

-Water from the Columbia River was filtered, treated and stored to cool the reactor. 

-30,000 gallons of water were pumped through the reactor every minute. 

sources/information: http://www.manhattanprojectvoices.org/location/b-reactor

- Intelligence-gathering operations were to firsthand see how close Germany was to developing its own atomic weapon. 

-By command of General Leslie Groves,actions of capturing most of the key German scientists was successful.

-Stores of uranium ore/nuclear raw materials/ thousands of documents on development of atomic energy were confiscated.

-Otto Hahn and Fritz Strassmann split the first uranium atom in Nazi Germany on December 21, 1938. Quickly realized immense power that could be yeilded.

-Otto Hahn and Fritz Strassmann split the first uranium atom in Nazi Germany on December 21, 1938.

-General George Marshall in late 1943 formalized the plan and established the Alsos Missions.

-Alsos Missions of the Manhattan Project were conducted inthree phases: Phase I - Italy; Phase II - France; and, Phase III - Germany.

-Headquarters mission established in London.

- Missions consisted of thirteen military personnel, including interpreters and six scientists. 

-Team members were familiar with the research of the United States and Great Britain and dutied to extract information through interrogation/observation of detailed scientific information on atomic energy.

- Alsos was commanded by Lt. Col. Boris T. Pash. Eventually Dr. Samuel Goudsmit came aboard as chief of the scientific component.

sources/ information: http://www.manhattanprojectvoices.org/location/alsos-mission-europe

-Ernest O'Lawrence constructed the first cyclotron at the University of California at Berkeley in 1929.

-Harvard physicists and engineers Harry Mimno, Kenneth Bainbridge, and Edward Purcell began contruction in 1936, the cyclotron began in the Gordon McKay laboratory.

-Harvard President James B. Conant and General Groves agreed Harvard would sell the cyclotron to US government for $1 million .

- "Cover story" developed was cyclotron was needed for medical treatment of military personnel.

-Sent  to St. Louis then to (Los Alamos).

-Massachusetts Institute of Technology

- The Rad Lab, as it was commonly known, advanced and accelerated radar development.

-An annual budget of $13 million,staff of over 4,000, and industrial contracts worth $1.5 billion; it was, as such, the single-largest war research laboratory.

sources/information: http://www.manhattanprojectvoices.org/location/cambridge

- Leo Szilard first realized the possibility of a nuclear chain reaction in 1933.

- Basement laboratory of Pupin Hall became home to a cyclotron, a type of particle accelerator known as “atom smashers,” 

-The results of such experiments provided valuable clues about the behavior of atoms.

-A scientific team at Columbia, including Dunning and chemist Harold Urey, invented and perfected the “gaseous diffusion”

- Columbia scientists were first to prove that the fissionable material in uranium that released energy when bombarded with neutrons.

- Columbia cyclotron continued to be used for experiments until 1965.

sources/information: http://manhattanprojectvoices.org/location/columbia-university

-Polonium, discovered by physicist Marie Curie, is a peculiar, is a toxic soft metal.

- When in contact with beryllium, the neutrons necessary to ignite the nuclear reaction are produced.

-Thomas, Monsato Chemical Company’s research director, convinced Monsato to undertake the polonium work, 

- Also convinced, his mother-in-law, Mrs. Harold E. Talbott to let them use the family’s grand Runnymede Playhouse with its giant ballroom, indoor tennis courts, and other facilities for the separation process.

sources/ information: http://manhattanprojectvoices.org/location/dayton

-By 1943 a renewed sense of urgency developed for an adequate material that withstood high pressure of corrosive gases.

-January 1943, interior-decorator Edward Norris and chemist Edward Adler had perfected an electro-deposited nickel mesh barrier.

-Groves authorized full-scale production of the “Norris-Adler” barrier .

-Houdaille Hershey Corporation took on the assignment on April 1, 1943 and began planning a new factory for the purpose in Decatur, Illinois.

- Kellex developed another promising barrier material—which combined desirable features Norris-Adler barrier and the compressed nickel-powder barrier held.

- Houdaille Hershey plant specifically designed for production of the Norris-Adler barrier.

-In January 1944, Groves decided to strip and re-equipt the Houdaille-Hershey plant for new barrier production.

-Workers at the plant worked with new process of filling the pipes with a plating solution and rotating them as the plating current.

sources/information: http://manhattanprojectvoices.org/location/decatur

-By 1946, over 2,600,000 pounds of uranium oxide had been produced material.

-14 % of the total uranium acquired by the MED.

-Grand Junction, Uravan, and Durango grew tremendously from mining influence.

sources/ information: http://manhattanprojectvoices.org/location/grand-junction-co

- “Little Boy” bomb dropped on Hiroshima on August 6, 1945, was developed here.

- Design was “bullet” of nuclear material fired into a second nuclear mass and very high speed in which created a critical mass.

-Gun-type bomb was not tested before it was used against Japan.

sources/information: http://manhattanprojectvoices.org/location/gun-site

-On August 14, 1945, Jackson Square where residents , at end of World War II , waved the banner headlines “WAR ENDS."

sources information: http://manhattanprojectvoices.org/location/jackson-square

sources/information: http://manhattanprojectvoices.org/location/nash-garage-building

-Groves, in late June 1944, approves construction for what would become the S-50 Thermal Diffusion Plant.

-Almost replicated version of Navy pilot plant in Philadelphia, consisted of  2,142 uniform columns.

- H. K. Ferguson Company, an engineering firm in Cleveland agreed to construct.

-Beat the deadline and completed the S-50 plant in just 69 days.

- In three plant process uranium product enriched; at S-50 (one to two percent U-235); 20 percent at K-25 plant; and Y-12 plant for the final enrichment .

-S-50 production plant required an enormous amount of energy and was shut down in 1946.

sources/information: http://manhattanprojectvoices.org/location/s-50

-Arrive at Lamy 10 miles away not knowing where they are going.

- Then directed to 109 E. Palace Avenue in Santa Fe.

- There Dorothy Scarritt McKibbin  informed their journey continued 35 miles along road up to the Pajarito Plateau.

-Mckibbin dealed with housing and care of Los Alamos residents.  Close friend and confidante of Oppenheimer.

-La Fonda (Spanish for "inn") was a favorite watering hole for the scientists and their wives.

-Oppenheimer asked physicists Bob Serber and John Manley to go to Santa Fe to spread the rumor that Los Alamos was making electric rockets.

-Castillo Street Bridge at Paseo De Peralta where German physcist/Soviet spy Klaus Fuchs agreed to meet his Soviet Agent, Harry Gold over summer of 1945. Advanced Soviet bomb prodject by two years.

sources/information: http://manhattanprojectvoices.org/location/santa-fe

-Tinian is less than forty square miles in size and located approximately 1,500 miles south of Tokyo.

- Tinian served as the headquarters of the 509th Composite Group.

- Taking of Tinian was preceded by the invasion of Saipan on June 15, 1944.

-Began June 24 and ended August 1, over 300 Americans and 6,000 Japanese lost their lives.

-Navy construction battalions ,SeaBees, began days after secure of island.

-Six runways, within two months, became the biggest air base in the world.

-Tinian was the forward operational base from which bomber flew to Japan.

-Twentieth Bomber Command launched relentless attacks on the Philippines, Okinawa, and mainland Japan.

-Overloaded with fuel takeoff crashes were common.

-Chosen as the base of operations for an atomic attack against Japan in February of 1945.

- 509th would only be utilized for the secret atomic bombing mission.

-At 2:45am on August 6, the B-29 - piloted by Colonel Paul Tibbets of the US Army Air Force took off. 

- August 6 at 8:15 am Hiroshima time, Little Boy by was dropped on Hirsohima. Minute to detonation.

-On August 14 it was decided that an additional attack was necessary.

-Hundreds of B-29s from withTorpex bombs converged on the Japanese city of Koromo to deliver the last attack of the war.

- Day later Japan surrenders.

sources/information: http://manhattanprojectvoices.org/location/tinian-island

-Radiation levels at the site remain about 10 times as high as natural background radiation.

-Trinity site was declared a National Historic Landmark district in 1965.

sources/information: http://manhattanprojectvoices.org/location/trinity-site

-American women were encouraged to go to work in nontraditional jobs that women in this country had never held before.

-

- College-educated women were recruited for their skills, but not always for their specialties.

-Once at Oak Ridge, the workers were fingerprinted, interviewed, assigned a job, and given a clearance badge.

-Oak Ridge center , a town of 70,000, workers in which were primarily women.

-Work had opened up for women and it was their patriotic duty to take it.

-Some women were recruited as spys, reporting any breaches in security to the higher-ups.

-Women were only allowed to visit their husbands if they had the proper clearance and documentation, proving they were married.

sources/information: http://www.brainpickings.org/index.php/2013/03/20/the-girls-of-atomic-city/

- Young physicist, graduate at the University of Chicago,  helped to construct detectors for monitoring the flux of neutrons in the first atomic "pile".

-Part of Enrico Fermi's group responsible for producing controlled self sustaining nuclear fission chain reaction.

Maria Goeppert Mayer

-Won the Nobel Prize in physics for her work in developing the theory of nuclear shell structure.

-Involved initially in theoretical studies of the thermodynamic properties of the uranium hexafluoride gas used in the gaseous diffusion.

- investigated the possibility of using photochemical reactions for isotope separation. 

-Later she worked at Los Alamos on energy release in nuclear explosions. 

Chinese American experimental physicist Chien-Shiung Wu

-Became famous for disproving the law of conservation of parity.

-Contributed to solving the problem of reactor "poisoning" when the large plutonium production reactors at Hanford were first turned on.

Physical chemist Isabella Karle

-Awarded the National Medal of Science for developing methods for determining crystal and molecular structures by x-ray diffraction.

-Worked for a short time on the chemistry of transuranic elements and the synthesis of plutonium compounds in Glenn Seaborg's laboratory in Chicago. 

Miriam Posner Finkel

-Ph.D. zoologist hired by the Metallurgical worked on establishing the basic toxicity levels of radionuclides. 

Naomi Livesay

-Experience in using electric calculating machines in the analysis of survey data.

-Work at Los Alamos in 1944. Soon was supervising a team that conducted calculations to track the blast wave of the conventional explosion then to track the shock wave of the fission detonation back out.

Lilli Hornig

- Chemist at Los Alamos, assigned as a staff scientist in plutonium chemistry. 

-She led a section in the Explosives Division on the development of explosive lenses.

Frances Dunne

-Aircraft mechanic at Kirtland Air Force Base

-Recruited as an explosives technician.

-Tested various configurations of the conventional explosives assemblies.

-Assembly crew for the world's first nuclear explosion, code-named Trinity at the Alamogordo Bombing Range on July 16, 1945. 

sources/ information: http://www.losalamoshistory.org/manhattan.htm

-Ground zero who received high radiation dosages died immediately or during the first day. One-third of all fatalities occurred by the 4th day; two-thirds by the 10th day; and 90% by the end of three weeks.

Injury Phases

1. First two weeks: mainly burns from rays and flames, and wounds (trauma) from blast and falling structures.
2. 3rd week through 8th week: symptoms of damages by radioactive rays, e.g., loss of hair, anemia, loss of white cells, bleeding, diarrhea. Approximately 10% of cases in this group were fatal.
3. 3rd and 4th months: “some improvement” in burn, trauma, and even radiation 
   injuries. But then came “secondary injuries” of disfiguration, severe scar formations (keloids), blood abnormalities, sterility (both sexes), and psychosomatic disorders.
4. Even now, after over half a century later, many aftereffects remain: leukemia, 
   A-bomb cataracts, and cancers of thyroid, breast, lungs, salivary glands, birth defects, including mental retardation, and fears of birth defects in their children, plus, of course, the disfiguring keloid scars.
5. *Estimated air dose of gamma rays: Hiroshima: 10,300 rads; Nagasaki: 25,100 rads.
   *Estimated neutron dosages: Hiroshima, 14,100 rads; Nagasaki: 3,900 rads.