Particle Collision Infrastructure for both Particle-Particle and Particle-Background Collision

[gsgall]

Reason

A large part of PIC modeling is Monte Carlo collisions between both species that need to be modeled as rays and species that are modeled as fluids, using zapdos. In order to implement efficient methods for these collisions, Null Collision method, we need to know the location of particles at the end of a trace.

Design

A PR has been submitted to MOOSE, #26043, to add a postTrace method to RayTracing so we can directly access information about the element and the particles in that element at the end of a ray tracing session.

A RayStudy User Object will be created which has a member variable which is a map in which the keys are elements and the values are either a list of particles in the key element or a list of pairs of particles in the key element. The list of a pairs of particles will be needed if we are using DSMC and a list of particles will be needed for the null collision method if we are using PIC and/or hybrid methods which couple to Zapdos.

Impact

This will enable collisional modeling for the plasma.