Transcript Fusion Powerpoint fusion_

Nuclear Fusion - SAMI 2010
Introduction
• “Every time you look
up at the sky, every
one of those points of
light is a reminder that
fusion power is
extractable from
hydrogen and other
light elements”
-Carl Sagan, 1991
Background
Fusion Basics
Nuclear Power
• Nuclear fission
– Where heavy atoms,
such as uranium, are
split apart releasing
energy that holds the
atom together
• Nuclear fusion
– Where light atoms, such as
hydrogen, are joined
together to release energy
The fuel of fusion
Even though the nuclear force is much stronger than
the electromagnetic one, the RANGE of the nuclear
one is much smaller.
nucleus
Range of nuclear
force
Range of
Electromagnetic
force
These don’t get close enough to fuse
together!
These get close enough to fuse together!
States of Matter
• Plasma is sometimes referred to as the
fourth state of matter
• In plasma the electrons
are stripped away from
the nucleus
Plasma Atoms
• Like charges repel
– Examples of plasma on
earth:
• Fluorescent lights
• Lightning
• Neon signs
Typical Plasmas
• Neon Signs
• Thermonuclear
• Lightning
• Fluorescent Lights
Plasma makes up the sun and the
stars
Characteristics of Typical
Plasmas
HOW FUSION REACTIONS
WORK
P-P Fusion Reaction
"P-P": Solar Fusion Chain
Inexhaustible Energy Supply
• Deuterium
– Constitutes a small percentage of the hydrogen in water
• Separated by electrolysis
• 1 barrel (42 gallons) water = ¾ oz. D = 32,000 gallons of oil
• Tritium
– n + Li
T + He
– Lithium is plentiful
• Earth’s crust
• Oceans
– Savannah, Georgia
– Canada, Europe, Japan
D-T Fusion Reactions
D + T => He-4 + n
An enormous payoff
• The fraction of “lost”
mass when H fuses into
He is 38 parts out of
10,000
• This lost mass is
converted into energy
• The energy released
from 1 gram of DT = the
energy from about 2400
gallons of oil
Energy-Releasing Reactions
Chemical Fission
Fusion
Sample
Reaction
C + O2 -> CO2 n + U-235 -> Ba-143 + Kr-91 + 2 n H-2 + H-3 -> He-4 + n
Typical
Inputs
(to Power
Plant)
Bituminous
Coal
UO2 (3% U-235 + 97% U-238)
Deuterium & Lithium
Typical
Reaction
Temp. (K)
700
1000
108
Energy
Released per
kg of Fuel
(J/kg)
3.3 x 107
2.1 x 1012
3.4 x 1014
E=mc2
• Einstein’s equation that equates energy and
mass
– E= energy
– M= mass
– C= speed of light (3 x 108 m/sec)
– Mass “lost “ in fusion is converted to energy
Plasma Confinement & Heating
Tokamak Schematic
Stars & Galaxies
Magnetic
Gravity
•Electromagnetic Waves
•Compression (gravity)
•Ohmic Heating (by electric
currents)
•Fusion Reactions (such as the
p-p chain)
•Neutral Particle Beams (atomic
hydrogen)
•Compression (by magnetic fields)
•Fusion Reactions (primarily D+T)
Laser-beam-driven Fusion
Inertial
•Compression (implosion driven by laser
or ion beams, or by X-rays from laser or
ion beams)
•Fusion Reactions (primarily D+T)
Fusion By Magnetic Confinement
NOVA Machine- Inertial
Confinement
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