Nuclear Fusion

Nuclear fusion Key words

1 Nuclear fusion proton

fusion isotope

proton

proton

proton

1 Nuclear fusion nuclear fusion, two or more light atomic nuclei join to make a more massive one. During the process, some of the mass of the nuclei is converted into energy. Nuclear fusion, which first occurred during the Big Bang, powers stars. It also occurs in hydrogen bombs. Currently scientists are working to control fusion so it can be used in nuclear reactors.

● In

helium nucleus

positron

positron

electron

electron

2 Deuterium is an isotope of hydrogen known as heavy hydrogen. The nucleus of a deuterium atom consists of one neutron and one proton. ● The fusion of two deuterium nuclei results in the formation of a helium-3 nucleus. A small amount of mass is converted into energy: Mass of two deuterium nuclei = ● Deuterium

starlight

2 Fusion of deuterium

2 x 2.014 = 4.028 u

Mass of helium-3 nucleus plus a neutron = 3.016 + 1.009 = 4.025 u

Mass converted to energy by fusion = 4.028 – 4.025 = 0.003 u

2 1H

2 1H

3 2 He

1 0n

deuterium

deuterium

helium-3

neutron

Energy released by the fusion reaction = 4.5 x 10-13 J Energy released per kilogram of deuterium is approximately 9 x 1013 J.

3 Tritium

2 1H

3 1H

4 2 He

1 0n

deuterium

tritium

helium-4

neutron

is another isotope of hydrogen. The nucleus of a tritium atom consists of two neutrons and one proton. ● The fusion of a deuterium nucleus and a tritium nucleus results in the formation of a helium-4 nucleus and the release of energy. The energy released per kilogram of deuterium and tritium is approximately 30 x 1013 J. ● This reaction produces more energy, and the fusion takes place at a lower temperature.

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● Tritium

3 Fusion of deuterium and tritium