Many people find it perplexing that to see the smallest detail, you need the largest energies, while the smallest energies will suffice for the largest detail. The reason is that detail can only be resolved when the the size of the detail is of the same order as the wavelength of whatever is being used to investigate that detail. Using the De Broglie relation
we have for a photon,
and for a matter particle
for small
This equation ignores relativistic effects which we can safely do for v not close to the speed of light.
To investigate the nucleus we need a wavelength of the order of
or smaller.
The highest energy gamma rays have energies of order 500GeV which corresponds to a wavelength of
Gamma rays of these energies can only be produced in cosmic processes.
The wavelengths required can be produced much more easily using charged particles such as electrons, protons or
An
particle has a mass of around
Since they are charged they can be easily accelerated through a voltage to produce the energy or wavelength required. Then
This is about 30% of the speed of light and is perfectly attainable. These speeds are produced by cathode ray tubes as they accelerate electrons to produce pictures on a screen.