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Nuclear Weapons

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Page 1: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Nuclear Weapons

Page 2: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Units of Radiation Dose• Roentgen – Ability to create a specified

electric charge per volume of air• Rem (Roentgen equivalent man) –Biological

effect of one roentgen of X-rays• Rad (Radiation absorbed dose) – Energy

absorption: 400,000 rads heat H2O 1 deg

• For general human exposure, these units are roughly equivalent

Page 3: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Background Radiation

• Cosmic Rays• Solar Wind• Decay of Natural Radioactivity• Typical Doses– Global Average 0.1 rem/year (80% natural)– Some areas up to 1 rem/year– Ramsar, Iran: up to 26 rem/year

Page 4: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Human Radiation Sources

• Nuclear Fallout from Atmospheric Testing (US and Russia, 1963; France, 1974; China, 1980)

• Chernobyl 1986• Uranium Mining• Radon release from construction and earth-

moving• Conventional power plants

Page 5: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Human Survival Limits

• 200 rem (whole body): few immediate fatalities

• 500 rem (whole body): 50% fatalities• 1000 rem (whole body): No survivors

Page 6: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Chain Reaction

Page 7: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Nuclear Fission• Chain reaction requires a critical mass to

proceed• 10 kg U-235 = 2.5 x 1025 atoms• 1,2,4,8 … 2.5 x 1025 = 85 steps• @ 1/1,000,000 sec per step = 1/10,000 sec• After 64 steps, T = 10,000 K (twice as hot as

sun)• Have only completed 1/1,000,000 of fission

Page 8: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Nuclear WeaponsTo get a nuclear explosion, you have to• Assemble a critical mass in millionths of a

second• Retain a high percentage of the neutrons• Hold the material together against

temperatures hotter than the Sun• Imposes limits on yield of weapon• Unless something is specifically designed to

be a nuclear weapon, it will not explode

Page 9: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Yields of Nuclear Weapons• Kiloton = 1000 tons of explosives = 4.2 x

1012 joules = 1012 calories– Texas City, Texas, April 16-17, 1947– Collapse of World Trade Center– Impact of 10-m asteroid

• Megaton = 1,000,000 tons of explosives = 4.2 x 1015 joules = 1015 calories– Magnitude 7 earthquake– Impact of 100-m asteroid

Page 10: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

“Das war keine gute Idee”

Page 11: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Effects of Nuclear Weapons• Direct ionizing radiation• Heat (Fireball)– Rising fireball sucks dust upward, creates

“mushroom cloud”– Any large explosion will create a “mushroom

cloud”

• Blast (Expansion of Fireball)• Fallout• Volume α Yield: Radius α 3√Yield

Page 12: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

All Large Explosions Make Mushroom Clouds

Page 14: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Weapons Terminology• Warhead: The Actual Explosive Component of

a Nuclear Weapon• Warhead Section: The Delivery Casing for a

Nuclear Weapon. Includes casing, radars, timers, detonators, etc

• When most people say “Warhead,” they actually mean “Warhead Section.”

• Tactical = Range < 500 km• Strategic = Range > 500 km

Page 15: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Some Nuclear Factoids• Nuclear weapons are always under armed

guard• Nobody Ever Goes Near a Nuke Alone. U.S.

Protocols Call for a “Two Man” Rule• There are persistent rumors we allowed

designs of our locking mechanisms to be leaked to the Russians

• Information on locations of nuclear weapons is classified “Secret” or above

• Do not confirm/deny

Page 16: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Nuclear Weapons Systems• All military explosive weapons have had

nuclear versions– Artillery Shells– Bombs– Depth Charges– Rockets– Missiles– Anti-Aircraft– Stationary charges

Page 17: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

DASA and SASCOM

Page 18: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

“Little Boy” Gun Type, Uranium

Page 19: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

“Fat Man” Implosion, Plutonium

Page 20: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Early Strategic Nuke

Page 21: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Early Strategic Nuke

Page 22: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Trinitite

Page 23: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Atomic Bomb

Page 24: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Delivery Systems

Page 25: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Titan Warhead

Page 26: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Minuteman Warheads

Page 27: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

MinutemanWarheads

Page 28: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Minuteman Missile Silo, SD

Page 29: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

MIRV

Page 30: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Tactical Nukes

Page 31: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Nuclear Artillery Shell

Page 32: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Atomic Cannon

Page 33: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

“Birdcage” for Artillery

Shell Fissionable

Material

Page 34: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Davy Crockett

Page 35: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

SADM

Page 37: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Cradle For Nuclear Artillery Shell

Page 38: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Palomares, Spain: My Bad

Page 39: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Russian Nukes

Page 40: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Nuclear Winter• Publicized by Carl Sagan and others in

1980’s• Global nuclear exchange would raise large

amounts of dust and soot into upper atmosphere

• Would absorb or reflect sunlight, cooling the surface

• Would be above most precipitation processes

• Did not happen in Gulf War 1991

Page 41: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Fusion• Natural: how stars (and the sun) generate

energy• Artificial and uncontrolled: Thermonuclear

Weapon (hydrogen bomb)• Fusion Reactor: controlled• “Energy source of the future. Always has

been, always will be.”

Page 42: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Core of the Sun• Energy output: 90 billion megatons/second• Energy output = 6 microwatts/kg – less than a

candle• Human body outputs 1.2 W/kg – 200,000

times greater• Trying to duplicate sun’s energy output not

practical on Earth• Energy takes 10,000 – 100,000 years to reach

surface

Page 43: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Uncontrolled Fusion• We cannot achieve T and P necessary to

use ordinary hydrogen• Have to use H-2 (deuterium) or H-3

(tritium)• Still need T = 1,000,000 K+• Initiated by a nuclear (fission) weapon• Fission weapons yield up to 20 kilotons• Fusion (hydrogen or thermonuclear)

weapons yield up to 20 megatons

Page 44: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Controlled Fusion

• Temperatures too high for any material• Need to contain by magnetic fields, achieve

small-scale reactions for short periods• Have not achieved break-even• Apparatus will be incredibly complex and

expensive• Reactions give off neutrons: there will still

be radioactive waste• No spent fuel or fissionable residue

Page 45: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological

Detecting Nuclear Explosions• Vela System (US)• Space: X-ray and Gamma Ray pulses• Atmospheric:– Double-humped light pulse– Initial Fireball– Obscured by ionized gas in shock wave– Revealed again as shock wave cools– Vela Incident, September 22, 1979

• Subsurface: Seismic First Motion Analysis

Page 46: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological
Page 47: Nuclear Weapons. Units of Radiation Dose Roentgen – Ability to create a specified electric charge per volume of air Rem (Roentgen equivalent man) –Biological