BEACH Documentation

BEACH (BEM + Accumulated CHarge) is a surface-charging simulator that couples Coulomb fields from charges on triangular boundary elements with test-particle tracking in batches. The current release focuses on charge accumulation on insulator surfaces. The Fortran runtime beach performs the simulation, while the Python CLI/API (beachx and the beach package) handles configuration checks, post-processing, and visualization.

Three-Minute Quick Start

python -m pip install -U pip setuptools wheel
python -m pip install beach-bem

mkdir run_periodic2
cd run_periodic2

beachx config init
beachx lint beach.toml

beach beach.toml
beachx inspect outputs/latest

beach reads beach.toml directly. High-level notation such as box_origin / box_size and mesh.groups is normalized by the Fortran parser.

Success Check

A normally completed run writes outputs/latest/summary.txt, and batches reaches the configured sim.batch_count. Then run beachx inspect outputs/latest to check absorbed and escaped particles, element charges, and mesh metadata. See Reading Output Files for the meaning of each output file.

What to Read Next

Goal	Page
Check outputs after the first run	Reading Output Files
Adapt a configuration from examples	Configuration Recipes
Look up every beach.toml key	Input Parameters Reference
Write high-level notation	beachx config / High-Level Notation Guide
Make the first plots	Post-processing Tutorial
Use the full Python API	Python Post-processing API Reference
Understand the numerical model	BEACH Algorithm Overview

Use Cases

Goal	Entry point
Run a small template mesh	Configuration Recipes, “Minimal plane-mesh run”
Choose a particle source model	Configuration Recipes and particles in Input Parameters Reference
Use two-periodic-axis boundaries	periodic2 in Configuration Recipes and Field Solvers and Boundary Conditions
Tune batch_duration	batch_duration Stability
Inspect implementation APIs	Fortran API and Fortran Dependency Map

Documentation Index

• Reading Output Files
• Configuration Recipes
• Input Parameters Reference
• beachx config / High-Level Notation Guide
• Post-processing Tutorial
• Python Post-processing API Reference
• BEACH Algorithm Overview
• Field Solvers and Boundary Conditions
• Particle Tracking and Charge Accumulation
• Coulomb FMM Core Details
• batch_duration Stability
• Execution and Development Workflow
• Fortran Dependency Map
• BEACH Agent User Guide

For API-level implementation details, use the FORD-generated Fortran API.