The OpenScience Laboratory

Remotely controlled Compton scattering: relativistic dynamics and the electron mass.

Background and nature of task

The rest mass of the electron is determined by observation of the angle dependent energy losses during X-ray scattering. 

The X-rays are generated when a high energy electron beam impacts on a molybdenum target. The scattering is then effected by placing a block of solid material in a beam of collimated X-rays from this source, as if they comprised a stream of particles. An electron that scatters an X-ray photon takes momentum and energy from it. The conservation of momentum and energy, both treated relativistically, combine to give a determination of the electron rest mass from the angular dependence of the energy of the scattered X-rays.

Usage

This experiment is restricted to Open University (OU) students studying modules from the OU Physical Sciences curriculum. It is available at specific times via an online booking system. Contact OpenScience@open.ac.uk to discuss options for access outside the OU Physical Sciences curriculum. Further breifing material will be available including a video tutorial on the mathematical basis for the measurement. 

Duration and pattern of use

It should take approximately 2-4 hours in preparation and 1 hour in real time remote control.