Subatomic Physics

328 The Electromagnetic Interaction
(a) Discuss the process of internal conversion.
(b) Assume that a particular decay has a half-life of 1 sec and a conversion
coefficient of 10. What is the nuclear half-life for bare nuclei, i.e., nuclei
stripped of all their electrons?
(c) The nuclide 111 Cd has a first excited state at 247 keV excitation energy.
If the electron spectrum of this nuclide is observed, lines appear. Sketch
the position of the conversion electron lines produced by the 247 keV
transition.
10.22. Consider Møller scattering as shown in Fig. 10.12 (symmetric case).
(a) Assume that the incident electron has a kinetic energy of 1 MeV. Compute
the angle θlab.
(b) Repeat the problem for an incident electron energy of 1 GeV.
(c) Compute the ratio of cross sections for parts (a) and (b) assuming that
the angular function f(θ) in Eq. (10.82) has the same value for both
cases.
10.23. Consider Møller scattering. Assume that the electrons in the target foil are
completely polarized along the direction of the incident electrons. Use the
Pauli principle to get an idea how longitudinally polarized incident electrons
will scatter if their spin is (a) parallel and (b) anti-parallel to the target spins.
Consider only the symmetric scattering shown in Fig. 10.12.
10.24. To study the high-energy behavior of photons, monoenergetic beams are required.
An ingenious way of producing such photons involves an intense laser
pulse that collides head-on with a well-focused electron beam. The photons
that are scattered by 180 ◦ acquire considerable energy. Compute the energy
of the photons from a ruby laser that are scattered by 180 ◦ from an electron
beam of energy
(a) 1 MeV.
(b) 1 GeV.
(c) 100 GeV.
10.25. Estimate the ratio of probabilities for the emission of a rho to that of a gamma
ray from a high-energy nucleon that passes close to another one.
10.26. Magnetic monopoles (magnetic charges) would have remarkable properties: