Nuclear fusion: lecture 9.2 ANuclear fusion: lecture 9.2 A

Fusion in Fusion in the Sunthe Sun

At extreme temperatures and pressuresAt extreme temperatures and pressures, , Hydrogen fuses into He in the core of the sun.Hydrogen fuses into He in the core of the sun.

Elements up to Calcium are created, also by Elements up to Calcium are created, also by fusionfusion

Hydrogen fusionHydrogen fusion

Nuclear fusionNuclear fusion

Light nucleiLight nuclei are are joined together, or joined together, or fused, to make fused, to make heavier nucleiheavier nuclei..

In stars, H fuses In stars, H fuses into He + gamma into He + gamma radiation + energyradiation + energyFusion is what Fusion is what causes stars to causes stars to shineshine

Stars fuse elements from H to FeStars fuse elements from H to Fe

Heavier elements are created by fusion inSupernova explosions

Solar system originsSolar system origins

Our solar system was Our solar system was probably made from probably made from the outer layers of a the outer layers of a supernova.supernova.

All the heavy elements All the heavy elements found on earth found on earth were were made in that explosion made in that explosion by by fusion fusion reactionsreactions

Planetary nebula IC418

Star-gas-star cycleStar-gas-star cycle

Can fusion be an energy source on Can fusion be an energy source on Earth?Earth?

+ uses Hydrogen, an abundant element.+ uses Hydrogen, an abundant element.

+ the oceans could provide power for + the oceans could provide power for millions of years.millions of years.

- Fusion creates dangerous neutron - Fusion creates dangerous neutron radiationradiation

- Experiments in making fusion energy are - Experiments in making fusion energy are just beginning to be successfuljust beginning to be successful

Fusion Fusion researchresearch

1 lb of Hydrogen could yield the energy of 1 lb of Hydrogen could yield the energy of 16,000,000 lbs of coal16,000,000 lbs of coal

Water would be the source for HydrogenWater would be the source for Hydrogen

Fusion Fusion reactorreactor

Magnets spin H plasma @100 million C, high pressureMagnets spin H plasma @100 million C, high pressure

The H fuses into He, releasing radiation and heatThe H fuses into He, releasing radiation and heat

The heat energy would be used to make electricityThe heat energy would be used to make electricity

Tokamak reactor, Princeton Tokamak reactor, Princeton UniversityUniversity

In 1993, achieved temperatures 3 X those of the sun