Chapter 36

What is the wavelength of an electron that is accelerated from rest through a potential difference of $1.00\cdot {10}^{-5}\mathrm{V}?$

Compton used photons of wavelength $0.0711\mathrm{nm}.$ a) What is the wavelength of the photons scattered at $\theta =180.$ ? b) What is energy of these photons? c) If the target were a proton and not an electron, how would your answer in (a) change?

A free electron in a gas is struck by an $8.5-\mathrm{nm}\mathrm{X}$ -ray, which experiences an increase in wavelength of $1.5\mathrm{pm}.$ How fast is the electron moving after the interaction with the X-ray?

An accelerator boosts a proton's kinetic energy so that the de Broglie wavelength of the proton is $3.5\cdot {10}^{-15}\mathrm{m}$ What are the momentum and energy of the proton?

Scintillation detectors for gamma rays transfer the energy of a gamma-ray photon to an electron within a crystal, via the photoelectric effect or Compton scattering. The electron transfers its energy to atoms in the crystal, which re-emit it as a light flash detected by a photomultiplier tube. The charge pulse produced by the photomultiplier tube is proportional to the energy originally deposited in the crystal; this can be measured so an energy spectrum can be displayed. Gamma rays absorbed by the photoelectric effect are recorded as a photopeak in the spectrum, at the full energy of the gammas. The Compton-scattered electrons are also recorded, at a range of lower energies known as the Compton plateau. The highest-energy of these form the Compton edge of the plateau. Gamma-ray photons scattered $180{.}^{\circ }$ by the Compton effect appear as a backscatter peak in the spectrum. For gamma-ray photons of energy $511\mathrm{KeV}$ calculate the energies of the Compton edge and the backscatter peak in the spectrum.