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Gamma ray

After emitting an alpha or beta particle, the nucleus will often still be ‘excited’ and will need to lose energy.

It does this by emitting a high energy electromagnetic wave called a gamma ray.

Gamma radiation does not consist of particles but as short wavelength, high energy electromagnetic radiation emitted from unstable nuclei.

It is normally emitted alongside alpha or beta radiation.

Gamma radiation has no mass and no charge.

It can be written as Îł or \(_{0}^{0}\textrm{Îł}\)

An example of beta and gamma decay of cobalt-60

Beta and gamma decay of cobalt-60:

°À(łć”ś27°š°ś”ś60°š°ÀłÙ±đłæłÙ°ùłŸ”ś°äŽÇ°š°À°ùŸ±Č”łółÙČč°ù°ùŽÇ·Éłć”ś28°š°ś”ś60°š°ÀłÙ±đłæłÙ°ùłŸ”ś±·Ÿ±°š+łć”ś-1°š°ś”ś0°š°ÀłÙ±đłæłÙ°ùłŸ”ś±đ°š+łć”ś0°š°ś”ś0°š°ÀłÙ±đłæłÙ°ùłŸ”śÎł°š°À)

Properties of nuclear radiations

The different types of radiation are often compared in terms of what stops them, their and how far they can travel in the air.

SymbolPenetrating powerIonising powerRange in air
AlphaαSkin or a thin sheet of paperHighless than 5 cm
BetaÎČ3 mm aluminium foilLowapproximately 2 m
GammaÎłLead/concreteVery lowmore than 1 kilometre (km)
Alpha
Symbolα
Penetrating powerSkin or a thin sheet of paper
Ionising powerHigh
Range in airless than 5 cm
Beta
SymbolÎČ
Penetrating power3 mm aluminium foil
Ionising powerLow
Range in airapproximately 2 m
Gamma
SymbolÎł
Penetrating powerLead/concrete
Ionising powerVery low
Range in airmore than 1 kilometre (km)
Alpha, beta and gamma rays passing through a hand, beta and gamma rays passing through aluminium and gamma rays stopping at lead.

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