Different ways of slowing down an individual particle

[qazwsxedc]

I was wondering how you can slow down a particle. I know you can have it run into something. I know if its charged, you can introduce it in an electric field. Is there any other way. I remember learning something about a specific type of field that slows down all mass passing though it, which increases the energy of the field. Can anyone help me out here?

 

[Bob S]

The most common way of slowing down charged particles (excluding electrons) is to use materials, such as beryllium, copper, or tungsten (among others) by making use of dE/dx, the energy loss based on collisions of the slowing particles with atomic electrons (not Coulomb scattering on nuclei). The major concern about using materials to stop the particles is multiple scattering, which increases the beam size (divergence). Very roughly, the energy loss is about 2 MeV of energy loss per gram/cm² (gram per cm-squared) of the material. Positive and negative particles (positive and negative muons, pions) have a slightly (very small) different dE/dx stopping distance. If the charged particles are bunched in time, then RF cavities can decelerate them by properly phasing the RF power. If the beam current is sufficient, power can be extracted from the beam. Electrons are stopped by collisions with high-Z nuclei that produce bremsstrahlung and electromagnetic showers of large numbers of mainly positrons and electrons. Uncharged strongly interacting particles (e.g., neutrons) are best slowed by collisions with low-mass nuclei, like hydrogen, such as in water or hydrocarbons, or in graphite. Neutrinos are uncharged weakly interacting particles, and usually pass through the Earth without any interaction at all.

Photons interact by either electromagnetic or nuclear interactions. Photoelectric effect, (up to k-shell binding energies of atoms), Compton scattering (up to a few MeV), and pair production (of positrons and electrons) will attenuate photons. So will nuclear interactions, like gamma,n interactions, such as O¹⁶(gamma,n)O¹⁵.

Ultra-cold (1 micro electron volt) neutrons can be further slowed down by letting them drift vertically upward. Roughly half cannot reach an elevation of 10 meters before stopping and falling back down.

Dark matter?? dark energy?? WIMPS?? neutralinos?? tachions?? monopoles??

 

[sir-pinski]

There are actually several ways to slow down an individual particle. As you mentioned, one way is to have it collide with another object, which can transfer some of its energy and momentum to the particle, causing it to slow down.

Another method is to use an electric field, as you mentioned. By placing a charged particle in an electric field, the field can exert a force on the particle, slowing it down.

In addition, there is also the concept of a "frictional force" that can slow down particles. This force is caused by the interaction between the particle and the medium it is moving through. For example, air resistance can slow down a particle as it moves through the atmosphere.

You also mentioned a specific type of field that can slow down all mass passing through it. This could be referring to a gravitational field, which can slow down particles with mass as they move through it. This is because the particle experiences a force of gravity, which can act to slow it down.

Overall, there are multiple ways to slow down an individual particle, including collisions, electric fields, frictional forces, and gravitational fields. Each method may be more effective depending on the specific properties of the particle and the situation. I hope this helps clarify the different ways of slowing down a particle.