: Historically, this document was maintained in Adobe FrameMaker. Because the original source files for this version were lost, it is primarily available as a legacy PDF. MCNP6.3 Release Documents : Technical reports from Los Alamos National Laboratory (LANL) LA-UR-24-24602
Why read this? Because the manual details the —the assumption that particles travel in straight lines between collisions. This is trivial in a vacuum but critical in magnetic fields (not in MCNP5) or curved geometries. mcnp5 theory manual
At its core, MCNP5 is a general-purpose code for simulating the transport of neutrons, photons, and electrons. Unlike deterministic methods that solve the Boltzmann transport equation through discretization and numerical integration, the Monte Carlo method relies on the stochastic simulation of individual particle histories. The theory manual establishes that the "solution" to a transport problem is achieved by sampling from probability distributions that describe physical interactions, effectively mimicking the random walk of particles through a medium. The Transport Equation and Random Walks : Historically, this document was maintained in Adobe
MCNP5 uses the famous (first described by Cashwell and Everett, 1959). The manual explains: Because the manual details the —the assumption that
Many researchers maintain personal copies for reference. If you are a student at an institution with an MCNP license, ask your professor for the docs/ folder. The PDF is typically named mcnp5_theory.pdf or LA-UR-03-1987.pdf .
Allowing a particle to survive an interaction with a reduced weight rather than being terminated, thereby increasing the information gathered per history. Geometry and Criticality