pointsource_sphere module

Module:

pointsource_sphere

Description of this file:

  • Solution of the point source within a sphere

  • The heterogenous sphere is divided into multiple shells

  • Only the absorption reaction is considered here for simplicity

  • It is assumed that the source does not absrob the neutrons

  • Although the source radius is defined, it is over-written with zero

Created on Sat May 17 18:20:00 2025 @author: Dan Kotlyar Last updated on Mon May 19 11:30:00 2025 @author: Dan Kotlyar

email: dan.kotlyar@me.gatech.edu

pointsource_sphere.PlotSigT(mc: PointSourceInSphere, yLower: float, yUpper: float)

Def for plotting sigma_total.

Parameters:

  • mc – A PointSourceInSphere() object

  • yLower (int) – Lower bound for y axis on plot

  • yUpper (array) – Upper bound for y axis on plot

class pointsource_sphere.PointSourceInSphere(nMC: int, S0: int, R: float, sigT: ndarray | list)

Bases: object

MC solution for a point source positioned in an heterogenous sphere

Parameters:

  • nMC (int) – number of repetitive monte carlo simulations

  • S0 (int) – number of source neutrons

  • R (float) – radius of the sphere in cm

  • sigT (array) – total cross section array for all the different regions

inps

container with inputs

Type:

dict

resAN

container with analytic results

Type:

dict

resST

container with surface tracking results

Type:

dict

resDT

container with delta tracking results

Type:

dict

times

container with execution times

Type:

dict

Raises:

  • TypeError – if nMC is not int

  • ValueError – if nMC is not positive

PlotDifferences()

Plots differences in fluxes

PlotFluxes(scheme)

Plots neutron fluxes for a given method.

Parameters:

scheme (str) – scheme to plot fluxes for (‘dt’, ‘wdt’, ‘all’, ‘st’)

PrintFOM(scheme: str)

Prints FOM for the desired scheme

Uses the average of the variance squared and time for the FOM:

FOM = 1/(sig^2 * time) where sig^2 = mean(sig^2(xyz)])

Parameters:

scheme (str) – scheme to plot fluxes for (‘dt’, ‘wdt’, ‘all’, ‘st’)

Solve(scheme)

MC solution using a specific random walk scheme

Parameters:

scheme (str) – neutron tracking scheme [‘st’, ‘dt’, ‘analytic’, ‘wdt’]

_Analytic()

Analytic solution

_SolveDT()

MC solution using delta tracking

_SolveST()

MC solution using ray tracking

_SolveWDT()

MC solution using weighted delta tracking routine.

Uses a Russian Roulette threshold of 0.25 to discard particles.

Call via PointSourceInSphere() object.

Based on:

L.W.G. Morgan, D. Kotlyar, 2015. “Weighted-delta-tracking for Monte Carlo particle transport,” Annals of Nuclear Energy, 85, 1184-1188.

class pointsource_sphere.WeightedNeutron

Bases: object

A class for neutrons. Kinda simple right now but we would ideally use this more and more and expand on it as more methods are built/added.

Only currently used in the weighted delta tracking routine.

inps

weight of the neutron

Type:

weight

setWeight(weight: float)

Updates the weight of the neutron.

Parameters:

weight (float) – new weight of the neutron