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The Bomb Test Programs 1946 - 1963. Between 16 July 1945 and 23 September 1992 the United States of America conducted (by official count) 1054 nuclear tests, and two nuclear attacks. What are the reasons and results?. Art work by Grant Powell. List of US atmospheric Bomb tests.
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The Bomb Test Programs1946 - 1963 Between 16 July 1945 and 23 September 1992 the United States of America conducted (by official count) 1054 nuclear tests, and two nuclear attacks. What are the reasons and results? Art work by Grant Powell
List of US atmospheric Bomb tests Pacific Atolls and Nevada desert areas
316 tests until October 10, 1963; Limited Nuclear Test Ban Treaty
Preparation of Population Test program needed psychological preparation of population down-playing internal impact while up-playing external enemy familiarizing population and society through media & propaganda
The Commies are coming, the Commies are coming! The Red Nightmare: Federally funded propaganda film. The tale of an ordinary American town and its life as a Communist satellite, with everyone becoming emotionless automations. Invasion, USA is the key cold war 'scare' picture. Unlike pacifist weepies such as Arch Oboler's Five, this show depicts a Soviet Union so aggressive, Senator Joe McCarthy wouldn't recognize it. The Fear Factor
Comic Book Industry Presenting violence and horror with “the good guys” beating “the bad guys”
TheAmericanHeroattheEndofTimes No doubt or criticism was voiced in media, film, and popular literature towards arms race, weapons development and testing!
Duck and Cover Training to be prepared and to accept the “unavoidable”!
Preparation and Shelter Public shelter and warning system was installed Purchasing private “atomic bunker” system became big business. Business based on fear and false information.
But there were limits … To realistic movies and or satire was suppressed or forbidden to avoid the generation of criticism and/or panic reactions.
Nukes as business motivator March 1, 1954 Hydrogen Bomb test on Bikini Atoll; Louis Réard, thought his daring new swimsuit would have an impact comparable to the impact of the bomb. Crater Fall-Out Pattern
Nukes became normal part of everybody’s life But accidents occurred and criticism grew slowly but surely!
The Nature of the Blast Blast—40-60% of total energy Thermal radiation—30-50% of total energy Ionizing radiation—5% of total energy Residual radiation (fallout)—5-10% of total energy The results of the weapons test programs • Kind and shape of blasts • Blast effects, range & damage • Thermal effects • Radiation effects
Classifications of blasts • Surface Blast: • fireball in touch with surface • vaporization of surface structures through blast • and firestorm, immediate radioactive fallout • High Altitude Air Blast: • fireball > 100,000 ft (>3000m) • interrupts satellite based communication • through electromagnetic pulse (EMP) • Low Altitude Air Blast: • fireball < 100,000 ft (without touching ground) • generates shock waves, pressure difference • artificial for large areal damage, sea battle • Subsurface Blast: • Underwater burst • generates surge
Surface Blast – the fireball Stokes August 1957 1500 Foot Balloon 19 kt • Central temperature: ~10,000,000 K • Immediate vaporization of material! • Central pressure: ~33000 atm • Radiation release & absorption in surrounding matter generates red-glow intense luminosity. • Expansion of fireball through internal pressure • Fireball rises like hot air balloon
Fireball expansion Pressure evolution within the fireball: temperature pressure Initial expansion speed v cs is the speed of sound in the vaporized gas is the specific heat ratio of the gas Five times earth gravitation escape velocity
The shock front development After ~10 second the fireball expands with constant rate of ~300 ft/s After ~ 1minute fireball has cooled and radiation emission ceases!
6ms 90 ms 16 ms 109 ms 18 ms 15.0 s
General Features – the mushroom the emergence of the mushroom shape • Absorption of cool air • triggers fast toroidal • circulation of hot gases • and causes upward • motion forming the • stem and mushroom. • Condensation of • water changes red • brownish color of • cloud towards white! • Strong upward wind • Drags dirt and debris • Into the cloud mixing • with radioactive material • Cloud rises in height with ~ 440 ft/s
Cloud Altitude Maximum altitude for cloud rise is reached after ~ 4min. RATE OF RISE OF THE RADIOACTIVE CLOUD FROM a I-MEGATON AIRBURST Height Time Rate of Rise (miles) (min) (mph) 2.0 0.3 330 3.0 40.7 270 4.0 61.1 220 5.0 102.5 140 6.0 123.8 27 Cloud height & cloud radius depend on the magnitude of the explosion, increase of both radius & height scales with explosion yield.