10. Gamma Decays

Question 1

What is gamma decay?

Answer 1

The deexcitation of the nucleus by emission of a photon

Question 2

What is the notation for excited nuclei?

Answer 2

They have a star afterwards e.g. X*

Question 3

What is an important property about the radiated photon?

Answer 3

It is real and transversely polarised

- Has a spin of 1

Question 4

What is the notation for the spin of the decaying and daughter nuclei?

Answer 4

J_i - Decaying nuclei

J_f - Daughter nuclei

Question 5

Describe the multipolarity of the photon

Answer 5

Dipole decay L = 1
Quadrupole decay L = 2
Octupole decay L = 3

Question 6

Describe what M3 and E1 would represent

Answer 6

M3 - Magnetic octupole

E1 - Electric dipole

Question 7

What is the parity of an electric dipole and magnetic dipole?

Answer 7

Electric dipole changes sign - q(r) -> q(-r) = (-1)^L

Magnetic doesn’t change parity q(r x v) = (-1) ^ L+1

Question 8

Describe how odd and even magnetic multipoles change the parity of the nucleus

Answer 8

Even electric don’t change, odd do

Odd magnetic don’t change, even do

Question 9

What is the probability relationship between magnetic transitions and electric

Answer 9

Magnetic are x2 less probable than electric