| 1945.1.2 |
U.S.A. |
David Greenglass's contact with Julius
Rosenberg, a Soviet intelligence agent, handing a sketch of implosion
lens and a list of asset candidates. |
| 1945.1.16 |
U.S.A. |
Start of plutonium separation at
Hanford. |
| 1945.1.20 |
U.S.A. |
Start of operation in the gaseous
diffusion plant using a supply of poorly enriched uranium to Calutron.
Development of teflon as a sealant. |
| 1945.1.20 |
U.S.A. |
Low altitude incendiary bombing of
Japan proposed by C.LeMay, Commander of B-29 bombers corps. |
| 1945.1 |
U.S.A. |
Verification of critical mass of
uranium235by Otto Frisch. Named Dragon experiment
by R. Feynman. Accident in February of neutron irradiation. A victim
died. |
| 1945.1 |
U.S.A. |
An ignition device for implosion
completed by Luis W. Alvarez. |
| 1945.2.4 |
|
Yalta talk. F. Roosevelt, W. Churchill and Y.
Stalin. Demanded unconditional surrender of Japan: A secret agreement
of attacking of Japan by Soviet Union. |
| 1945.2.5 |
U.S.A. |
Transport of plutonium239
from Hanford to Los Alamos as nitric acid solution. |
| 1945.2.7 |
U.S.A. |
Implosion lens completed by G.
Kistiakowsky. |
| 1945.2 |
U.S.A. |
Schedule of Trinity test decided.
Implosion will be employed only in plutonium bomb. |
| 1945.2 |
U.S.A. |
Start of operation in Liquid Thermal
Diffusion plant, supplying poorly enriched uranium to Calutron. After
June, uranium was processed in the order of liquid thermal diffusion
plant, gaseous diffusion plant and
Calutron. Improvement of enrichment with gaseous diffusion plant. |
| 1945.2 |
U.S.A. |
Tinian recommended as the Dispatch
base for A-bomb B-29 by commander Frederick L. Ashworth. |
| 1945.2.16 |
U.S.A. |
Klaus Fuchs handed Soviet intelligence
agent data of implosion system. He refused to receive 1500 dollars
reward. |
| 1945.2.28 |
U.S.A. |
Leaders of Manhattan Project including
Groves, Office of Scientific Research and Development section head and
Harvard President James Bryant Conant, Hans Bethe, George Kitiakowsky
and Richard Tolman met in Oppenheimer's office and decided tentatively
to develop the lensed, solid-core Christy implosion design as a combat
weapon. |
| 1945.3.10 |
U.S.A. |
100,000 victims killed in large air
attack on Tokyo: 234 B-29 bombers with 1665 tons of incendiary bombs. |
| 1945.3.15 |
U.S.A. Germany |
US air force attacked
Metal-refining plant in Oranienburg (15 miles north of Berlin) to
prevent German production of metallic uranium. |
| 1945.3 |
Germany |
Start of experimental operation of B-8
nuclear reactor by W. Heisenberg, K. Diebner, Carl F. von Weizsaocker,
Hans Bethe and others. A cylinder type reactor employing graphite as
neutron reflector and heavy water as modulator. Did not achieve the
critical state. |
| 1945.4.12 |
U.S.A. |
Verification of critical mass of
Plutonium 239 by O.Frisch in Dragon Experiment. |
| 1945.4.12 |
Japan |
Riken Scientific Institute destroyed: End
of Japanese A-bomb project. |
| 1945.4.12 |
U.S.A. |
Sudden death of President Roosevelt.
Replaced by Harry S. Truman, the vice president. H. Stimson first
explained Manhattan Project to President
Truman in the evening. |
| 1945.4.17 |
Germany |
German uranium ore found by commander
John Lansdale, Jr. of US army special unit (ALSOS). At a shed in
Stuttgart. Supplied to Manhattan
Project |
| 1945.4.23 |
Germany |
Reactor at Heigerloch seized by U.S.
army (ALSOS). Commanders B. Pash and Samuel A. Goudsmit. Goudsmit is
Heisenberg's friend. Goudsmit's parents had been killed by Nazi in a
gas chamber. |
| 1945.4.24 |
Germany |
German atomic scientists arrested in
Hebingen. [C. Weizsaecker, O. Hahn, Max von Laue] |
| 1945.4.25 |
U.S.A. |
Truman and Stimson discuss details of
Manhattan Project. |
| 1945.4.26 |
Germany |
Metal uranium and heavy water found by
ALSOS. |
| 1945.4.27 |
U.S.A. |
The 1st Target Committee meets.
[L.Groves, Thomas F.Farrell,J.Neumann and William G.Penny] Japan, July
or August. Visual flying by a
B-29 bomber with the range of 2500km or less. |
| 1945.5.1 |
Germany |
Death of Adolf Hitler. |
| 1945. 5. 2 |
Germany |
Berlin occupied. |
| 1945,5.3 |
U.S.A. |
W. Heisenberg arrested by U. S. army
ALSOS in Welfeld. |
| 1945.5.8 |
Germany |
Germany surrenders to allied forces. |
| 1945.5.9 |
U.S.A. |
Interim committee on nuclear power
meets: Henry Stimson, Ralph Bard, Vannevar Bush, James Byrnes, William
Clayton, Karl Compton, George
Harrison: By invitation: Harvey Bundy. Predicts development of nuclear
weapons
by Soviet Union in 7 years. |
| 1945.5.10 |
U.S.A. |
The second Target Committee meets
in Los Alamos: L. Groves, General Farrel, Colonel Seeman, Captain
Parsons, C. Lauritsen, Major Derry, Drs Ramsey, Dennison, Stearns,
Tolman, Oppenheimer, von Neumann, Wilson,
Penny, Bethe, Robert. The first choices of targets for nuclear weapons
are:
a. Kyoto, b. Hiroshima, c. Yokohama, d. Kokura Arsenal. |
| 1945.5.25 |
U.S.A. |
Operation of Kyushu invasion decided
by Douglas MacArthur (army), Chester Nimitz (navy) and Henry H. Arnold
(army air corps). Named " Operation Olympiad," scheduled for November 1. |
| 1945.5.28 |
U.S.A. |
Joseph C. Grew, undersecretary of the
State Department, of predicts Japanese surrender to President Truman. |
| 1945.5.28 |
U.S.A. |
L. Szilard expresses his opinion
against use of A-bomb to Presidential advisor J. Byrnes. Rejected. |
| 1945.5.28 |
U.S.A. |
The third Target Committee meets.
Given report of test bombing carried out in Cuba by Colonel P. Tibbets. |
| 1945.5.30 |
U.S.A. |
Stimson tells L. Groves to exclude
Kyoto from list of A-bomb targets. |
| 1945.5.31 |
U.S.A. |
Recommendation on the immediate use of
nuclear weapons given by the Interim Committee: Byrnes, Stimson, G. C.
Marshall, Groves, Harvey
H. Bundy, J. Conant, Compton, Lawrence, Fermi, Oppenheimer. Inviting
Soviet
Union to Trinity proposed by Oppenheimer. Decided not to notify Japan
before
dropping A-bomb. Objections by Szilard discussed. |
| 1945.5 |
U.S.S.R. |
German 130 tons uranium oxide found in
a tannery in Berlin right on the border of American-occupied territory
was seized by Soviet army and shipped to Soviet Union. |
| 1945.5 |
U.S.A. |
Joseph Rotblat resigns of from Los
Alamos because of Germany's surrender. Later he founded Pugwash
Conference. |
| 1945.5 |
Soviet Union |
German uranium seized: over 100
tons in Belgium. |
| 1945.6.2 |
U.S.A. |
Confidential data including information
of Trinity, atomic bomb, explosive materials handed by Klaus Fuchs to a
Soviet agent. |
| 1945.6.3 |
U.S.A. |
David Greenglass handed to the same
agent contacting with Klaus Fuchs the sketch of implosion lens and
names of asset candidates. Received 500 dollars reward. |
| 1945.6.6 |
U.S.A. |
Recommendation of A-bomb use by
Interim Committee conveyed to President Truman by Stimson. |
| 1945.6.10 |
U.S.A. |
The 509th Composite Group arrives at
Tinian with 11 B-29 bombers. |
| 1945.6.11 |
U.S.A. |
James Frank committee recommends
notification before use of A-bomb: J. Frank, Leo Szilard, Eugene
Rabinowitch. Seven scientists in Chicago recommended a show of force
demonstration. |
| 1945.6.18 |
U.S.A. |
Estimation of 63000 war dead or
wounded in Operation Olympiad (Kyusyu invasion) by General G.C.Marshall. |
| 1945.6 |
U.S.A. |
Assembly of the plutonium bomb for
Trinity. |
| 1945.7.2 |
U.S.S.R. |
Confidential data obtained by
espionage agents from USA were shown to Igor Kurchatov.） |
| 1945.7.3 |
U.S.A. |
Casting of a warhead for uranium235
bomb. |
| 1945.7.12 |
U.S.A. |
Plutonium core arrives at Alamogordo. |
| 1945.7.13 |
U.S.A. |
Explosive assembly arrival at
Alamogordo. |
| 1945.7.14 |
U.S.A. |
A preparatory implosive experiment for
Trinity failed. The defect explosive was replaced by hand work. |
| 1945.7.14 |
U.S.A. |
Gadget for Trinity completed by Norris
E. Bradberry and others. Installed at top of 30m high tower. |
| 1945.7.15 |
U.S.A. |
Preparatory implosion experiment
declared indecisive by H. Bethe. |
| 1945.7.16 |
U.S.A. |
TRINITY test. After 90 minute
delay for bad weather, at 5:29:45. Explosive force of 18.6 kilotons of
TNT. |
| 1945.7.16 |
U.S.A. |
Shipping of Little Boy by cruiser
Indianapolis, 4 hours after Trinity. |
| 1945.7.17 |
U.S.A. |
Petition to President Truman against
the use of nuclear weapons by L. Szilard and 70 scientists. |
| 1945.7.20 |
U.S.A. |
Allied Commander D. Eisenhauer advises
President Truman not to use A-bomb; it is unnecessary. |
| 1945.7.21 |
U.S.A. |
Report from L. Groves of successful
Trinity conveyed to President Truman staying in Potsdam: Later W.
Churchill told H. Stimson that Truman's
reaction was clearly observable. |
| 1945.7.23 |
U.S.A. |
Telegraph by George L.Harrison to
Potsdam informing that dropping A-bomb on Japan is possible after
August 1. |
| 1945.7.23 |
U.S.A. |
Completion of the 2nd plutonium core. |
| 1945.7.24 |
U.S.A. |
H. Truman told Y. Stalin about A-bomb
experiment. Stalin was already informed by spy of Trinity but never
revealed it. |
| 1945.7.25 |
U.S.A. |
Approval by President Truman staying
at Potsdam of the order to bomb Japan with A-bomb. The order was
written by L. Groves. |
| 1945.7.26 |
U.S.A. |
Cruiser Indianapolis arrives at
Tinian. Little Boy is unloaded. |
| 1945.7.26 |
U.S.A. |
Shipping of uranium-235 warhead to
Tinian: by C-54 transport plane. |
| 1945.7.26 |
U.S.A. |
Shipping of plutonium core and the
initiator to Tinian by C-54 transport plane. |
| 1945.7.26 |
|
Potsdam Declaration announced, demanding
unconditional surrender of Japan. |
| 1945.7.30 |
U.S.A. |
Cruiser Indianapolis sunk by a torpedo
attack from a Japanese
submarine, only 4 days after unloading of A-bomb. |
| 1945.7.31 |
U.S.A. |
Assembling Little Boy, waiting
recovery of weather. |
| 1945.8.2 |
U.S.A. |
Parts of Fat Man arrive at Tinian. |
| 1945.8.4 |
U.S.A. |
Briefing to crew of B-29 bombers of
the 509th corps. Presentation by William Parsons of documentary film of
Trinity. |
| 1945.8.5 |
U.S.A. |
Bombing date of August 6 decided by
Curtis LeMay. Installation of Little Boy in a B-29 bomber named Enola
Gay, after Captain Tibbets' mother. |
| 1945.8.6 |
U.S.A. |
Bombing Hiroshima with Little Boy
by Paul W. Tibbets, Robert Lewis, Thomas Ferebee, William S. Parsons,
Morris Jeppson, and others,
at 08:16: 45. Explosion equivalent to 12.5 kilotons of TNT from 60 kg
uranium235.
Bomb's gross weigh was 4 tons. 140,000 civilian citizens were killed.
Hibakusya
(survivors) more than 300,000.Physical ailnesses due to radiation
exposure,
short term and long term effects. |
| 1945. 8. 7 |
U.S.S.R. |
Lavrenti Pavlovich Beria was appointed
to the head of Soviet atomic bomb project by Stalin. |
| 1945.8.7 |
U.S.A. |
Statement by President Truman of
A-bomb attack from Cruiser Augusta in Atlantic Ocean on the way back
from Potsdam. |
| 1945.8.8 |
Soviet Union |
Declaration of war against Japan,
just after the German surrender, as promised in Yalta talk. |
| 1945.8.8 |
U.S.A. |
Fat Man assembled and installed in a
B-29 bomber. |
| 1945.8.9 |
Soviet Union |
Attacks Japan by invasion of
Manchuria. |
| 1945.8.9 |
U.S.A. |
Bombing Nagasaki with Fat Man
by Charles W.Sweeney, Frederick L.Ashworth, and others. Target changed
from Kokura to Nagasaki because of
poor visibility. 20 seconds visibility over Nagasaki. Time 11:02:00.
Explosion
equivalent to 22 kilotons of TNT, using 8 kg plutonium 239.
Bomb's
gross weight 4.5 tons. 70,000 civilian citizens were killed. |
| 1945.8.9 |
Japan |
Decision accepting Potsdam Declaration at
midnight meeting of ministers before Tennou Hirohito. |
| 1945.8.10 |
Japan |
Sending word of acceptance of Potsdam
Declaration through Switzerland,
requesting Tennou's position to be kept. J. Byrnes wished to reject it,
nevertheless, H. Truman accepted. |
| 1945.8.11 |
U.S.A. |
Interruption of transport to Tinian of
the 2nd Plutonium core and initiator by the order of G.C. Marshall. The
next plutonium bomb could
possibly have been dropped on August 17 or 18. |
| 1945.8.12 |
Japan |
Response of U.S.A. to Japanese request. |
| 1945.8.15 |
Japan |
Unconditional Surrender by Japan. The end
of the World War II. |
| 1945.8.20 |
U.S.S.R. |
Special Commitee on the Atomic Bomb
formed. [Georgi Malenkov, Boris Vannikov, Avrami Zavenyagin, Mikhail
Peruvuhin, Peter Kapitza and Igor Kurchatov] |
| 1945.9.5 |
Canada |
Igor Gouzenko, a Soviet espionage,
escaped from Soviet Embassy carrying 109 reports, resulting in arrest
of 22 Soviet agents. |
| 1945.9.15 |
U.S.A. |
Manufacturing A-bomb reported:
Presented to L.Groves by major Lauris Norstad. An estimation that 204
atomic bombs are required if a hypothetical enemy is Soviet Union. The
start of cold war. |
| 1945.9.28 |
U.S.A. |
Scientific Panel of the Interim
Committee recommends against H-bomb development. [Compton, Lawrence,
Germi, Oppenheimer.] |
| 1945.10.16 |
U.S.A. |
Resignation of R. Oppenheimer from Los
Alamos. Replaced by Norris E. Bradbury. |
| 1945.11.2 |
U.S.A. |
" A Message to Los Alamos" speech by
Oppenheimer, his resignation lecture foreseeing the atomic age. |
| 1945.11.15 |
|
Truman-Attlee-King declaration, the New Quebec
agreement. A doctrine that
initiative relating with the knowledge of atomic energy is kept by
U.S.A.,
G.B. and Canada. Atomic Energy Commission in United Nations proposed. |
| 1945.11.23 |
Czechoslovakia |
Soviet Union concluded a secret
agreement with Czechoslovakia granting it exclusive rights to all
uranium mined within country. Jachymov ores is that from which Marie
Curie first extracted polonium and radium. |
| 1945.11.24 |
Japan |
Cyclotrons destroyed by U.S. Army: 2 in
Tokyo, 3 in Osaka and Kyoto. |
| 1945.12.22 |
England |
Repatriation of German scientists to
West Germany by U.S.A. |
| 1945.12.24 |
Soviet Union |
Start of developing A-bomb
officially notified to U.S. ambassador |
| 1945.12 |
U.S.A. |
ENIAC (A computer with 18,800 vacuum
tubes, 140 kw, 30 tons) ran a first rough version of the thermonuclear
calculations. Los Alamos prepared a half million punched cards of data.
|
| 1946.1.25 |
U.S.S.R. |
Atomic bomb project decided (imitating
US-model).[Stalin, Beria, Morotov, Kurchatov] |
| 1946.3.5 |
U.S.A. United Kingdom |
Winston Churchill's
speech of Iron Curtain at a small Protestant men's college in Fulton,
Missouri. Nothing less than a call to an all-out atomic race. |
| 1946.3.17 |
U.S.A. |
International Control of nuclear power
proposed: Dean Gooderham Acheson. Report by R. Oppenheimer. |
| 1946. 4. 2 |
U.S.S.R. |
Atomic bomb laboratory site at Sarov,
400 km east to Moskow. Soviet Los Alamos. |
| 1946.4 |
U.S.A. |
First conference on development of
"Super" (h-bomb).
Meeting of E. Teller, E. Konopinsky, J. Manley, P. Morrison, von
Neumann,
S. Ulam, N. Bradberry and K. Fuchs at Los Alamos. Robert Serber opposed
the development. Propose a mixture of deuterium and tritium in a
cylindrical
container ignited by the fireball of atomic bomb. |
| 1946.6.14 |
U.S.A. |
Nuclear Control Plan by Bernard M.
Baruch presented in United Nations: International control of nuclear
power. It was counterattacked
by a plan by Soviet Union of prohibition of manufacturing atomic bombs. |
| 1946.6 |
U.S.A. |
Stockpile of nuclear weapons: 9 Fat
Man bombs. Rate-limiting step is plutonium production. |
| 1946.7.1 |
U.S.A. |
The Crossroads Series tests. The purpose
of the tests was to examine
the effects of nuclear explosions on naval vessels, planes, and
animals.
A fleet of surplus and captured ships anchored in the Bikini Atoll
lagoon
in the Marshall Islands were used as targets. The weapons used were Mk
3A
("Model 1561") Fatman-type atomic bombs, essentially unmodified
from the wartime designs. Test ABLE at 22:00 30 June 1946, height of
burst
160 m. Dropped by B-29 "Dave's Dream", Fell 980 ft short and 1870
ft left of target. Test BAKER at 21:35 24 July 1946, Mk 3A fission bomb
(23 Kt) sub-surface test, depth of burst 27.5 m. Wall of intensely
radioactive
spray contaminates target fleet. |
| 1946.12.25 |
Soviet Union |
Start of operation of a nuclear
reactor (F-1): 100w, using
400 tons of graphite and 50 tons of uranium seized in Germany. |
| 1946 |
U.S.A. |
Edward Teller invented a spherical,
layered design of nuclear thermal weapon, called "Alarm Clock" (it
might wake up new generation of nuclear explosives). |
| 1946 |
U.S.S.R. |
"Utilization of the nuclear energy of
the light elements" by I.I.Gurevich, Y.Zeldovich, I.Pomeeranchuk,
Y.Khariton. |