Undergrad Interaction time between charged particles

[oksuz_]

Hi,

I was wondering that if there is some kind of interaction time between two charged particles. Imagine an electron shoot to ionize an atom. This electron interacts one of the electrons in the atom. Does the ionization depend on the velocity of the incoming electron? Is it possible that when it is slower than a certain velocity, it causes ionization, however, after this certain velocity, it does not cause ionization? To me, there should be enough time for a certain distance between the two in order to cause ionization. If the incoming electron is too fast, there would not be enough time for complete interaction which causes ionization.

Any comment would be appreciated.

 

[mfb]

Does the ionization depend on the velocity of the incoming electron?

Yes, as the velocity determines the energy, for example. In general higher velocities are more likely to lead to ionization, and if the velocity is too low you cannot ionize an atom at all.

There is no "minimal ionization time" or anything like that.

 

[oksuz_]

Yes, as the velocity determines the energy, for example. In general higher velocities are more likely to lead to ionization, and if the velocity is too low you cannot ionize an atom at all.

There is no "minimal ionization time" or anything like that.

I was just trying to understand why slower charged particles cause more ionization than those faster.

When a proton and a deuteron were hit by neutrons, the energy transfer would be lower for the neutron-deuteron collision since deuteron is heavier. So, there would be two like & equal charged particles with different energies. In that situation, which particle can cause more ionization?

thank you.

 

[mfb]

I was just trying to understand why slower charged particles cause more ionization than those faster.

Well, it depends on the energy range. At low energies more energy means more ionization, then there is a range where it goes down, and then there is a range where it goes up again.

When a proton and a deuteron were hit by neutrons, the energy transfer would be lower for the neutron-deuteron collision since deuteron is heavier. So, there would be two like & equal charged particles with different energies. In that situation, which particle can cause more ionization?

Ionization and elastic scattering are different processes.