Why do relativistic particles lose energy more quickly as they go through matter?

1. Apr 22, 2015

rwooduk

I understand that slower particles will be subject to the electric fields of the material for longer and lose energy, but why should relativistic particles also lose energy quickly?

The only idea we have is that there is a lorentz contraction of the electric field, BUT why then would that influence the traversing particle more?

thanks for any ideas.

Last edited by a moderator: Apr 22, 2015
2. Apr 22, 2015

Staff: Mentor

Quicker than what, slower particles? Why do you think they would do that?
As general as you wrote it here, this is not true. For most charged particles there is a minimum of energy loss per distance at relativistic speeds - slower particles lose much more energy, faster particles lose a bit more.

3. Apr 22, 2015

rwooduk

Hm, as I understood it slow moving particles and relativistic particles lose energy more quickly than those inbetween those speeds. I was trying to understand why relativistic particles will lose energy more quickly than those at 'intermediate' speeds. If the field is lorenz contracted then would it see a more "concentrated" field?

4. Apr 22, 2015

Staff: Mentor

The electrons see a more "concentrated" field from the fast particle in the Bethe formula, right.

The minimum is roughly at $\gamma = 3$ which is certainly in the relativistic region.

5. Apr 22, 2015

rwooduk

Great. Many thanks for the replies!