Rutherford scattering

Inside the Nucleus

Wave or Particle?

Deep inelastic scattering




Event pictures

More Examples

Identifying events

Useful links 



If you want to know more

Fundamental particles


Cross section

Energy units

Virtual photons

Rutherford's Notebook


So what is an MeV?

The standard unit of energy is the Joule, such that 1 Joule is equal to the work done by a force of 1 Newton in moving a distance of 1 metre (in direction of the force).   However using this for particles seems a bit silly when everything occurs on such a small scale.  Physicists have found that a more useful unit of energy is the MeV or 106eV, i.e. Mega electron Volt or 106 electron Volts - an electron volt?  1 eV is defined to be the energy required to move an electron through a potential difference of 1 Volt.  As the charge on the electron is -1.6x10-19C. it means that there are 6.25x1018eV in 1 Joule (or conversely 1 eV is 1.6x10-19 Joules).

and a GeV?

Just as an M means 106, so a G represents 109 (Giga), which is useful as we head to higher energy physics