LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION – PHYSICS
FOURTH SEMESTER – APRIL 2011
PH 4808 – NUCLEAR PHYSICS
Date : 09-04-2011 Dept. No. Max. : 100 Marks
Time : 9:00 – 12:00
PART-A
Answer all questions (10 x 2 = 20)
- Define the fissionability parameter. Estimate its value.
- Write down the Bethe-Weizsaker mass formula and explain the various terms occurring in it.
- Name the 3 types of exchange forces and also the single force which does not possess the exchange character.
- Name the various types of central potential available to solve the deuteron problem in nuclear physics.
- Identify the type of transition either Fermi or Gamow-Teller or both in the following reaction.
n
- On the basis of nuclear shell model, determine the spin and parity of B11 after writing down the nucleon configuration.
- Write down the Geiger Nuttal law and explain the various terms in it.
- What is Gamow factor in alpha decay? What does it depend on?
- Give the Gell-Mann-Nishijima formula. Explain the various quantities in the formula.
- What are strange particles? Give examples.
PART B
Answer any four questions (4×7.5=30)
- Write a note on the meson theory of nuclear forces.
- What are the important features of the Levy’s mass formula?
- Outline the Optical model of nuclear reactions.
- How are neutron stars formed?
- Explain the meson octet structure of elementary particles.
PART C
Answer any four questions (4×12.5=50)
- How are the experimental observations of the deuteron explained using the quantum mechanical theory?
- Derive the semi-empirical mass formula of Weizacker.
- Derive the Breit-Wigner single level formula for resonance scattering.
- Describe the important features of the Fermi’s theory of beta decay.
- (a) The baryon decuplet predicts the Ω– hyperon. What are its quantum numbers? (6)
(b) Discuss the possible decay modes of Ω- allowed by the conservation laws and show that the weak decay is the only possibility. (6.5)