wakis 0.8.0

Open-source Wake and Impedance Solver

wakis is a 3D Time-domain Electromagnetic solver that solves the Integral form of Maxwell's equations using the Finite Integration Technique (FIT) numerical method. It computes the longitudinal and transverse wake potential and beam-coupling impedance from the simulated electric and magnetic fields. It is also a multi-purpose solver, capable of simulating planewaves interaction with nano-structures, optical diffraction, and much more!

About

🚀 Some of wakis features:

• Wake potential and impedance calculations for particle beams with different relativistic $\beta$
• Material tensors: permittivity $\varepsilon$, permeability $\mu$, conductivity $\sigma$. Possibility of anisotropy.
• CAD geometry importer (STL & STEP format) for definition of embedded boundaries and material regions, based on pyvista, with sub-cell smoothing added in v0.8.0.
• Snappy Smart mesh added in v0.6.2
• Boundary conditions: PEC, PMC, periodic, first-order Mur absorbing boundaries (abc), PML and CPML, added in v0.8.0
• Different time-domain sources: particle beam, planewave, gaussian wavepacket
• 100% Python, fully exposed API (material tensors and fields $E$, $H$, $J$), with matrix operations based on numpy and scipy.sparse. Routines ensure multithreaded calculations using Intel's mkl-service.
• 1d, 2d, 3d built-in plotting on-the-fly
• Optimized memory consumption & GPU acceleration using cupy/cupyx on double and single precision: added in v0.6.1
• CUDA-aware MPI parallelization with mpi4py and ipyparallel: added in v0.6.0

🧩 Other complementary tools in the ecosystem:

• Wakefield extrapolation via broadband resonator fitting with PIML iddefix evolutionary algorithms
• Non-equidistant Filon Fourier integration with neffint
• Beam-induced heating estimation due to impedance with bihc

📣 Tag and version changes are described in each Wakis GitHub release.

• For specific needs, please contact the developer 👩‍💻👋: elena.de.la.fuente.garcia@cern.ch

How to use

📖 Documentation, powered by sphinx, is available at wakis.readthedocs.io

Check 📁 examples/ and notebooks/ for different physical applications:

• Planewave interacting with a PEC or dielectric sphere
• Gaussian wavepacket travelling through vacuum / dielectric
• Custom perturbation interacting with PEC geometry
• And of course, full Wakefield simulation of different accelerator components on CPU, GPU and with MPI.

Check 🌐📁 SWAN_tutorial/ for hands-on notebook examples ready to run on CERN's SWAN service's GPUs (A100, Tesla T4):

Check 🌐📁 wakis-benchmarks/ for beam-coupling impedance calculations & comparisons to the commercial tool CST® Wakefield solver:

• PEC cubic cavity below cutoff (mm) and above cutoff (cm)
• Conductive cubic cavity below cutoff
• Lossy pillbox cavity (cylindrical) above cutoff
• Simulations using beams with different relativistic $\beta$

Check 🌐📁 BE-Seminar-demo/ for a complete live demonstration of Wakis usage.

Installation

Wakis supports Python 3.9 - 3.14 and can be installed in any conda or venv environment.

📖 For a detailed installation guide (GPU, MPI setup, FAQs), check our documentation.

Install via PyPI

For basic usage, simply run:

pip install wakis

For additional features, including interactive 3D plots in Jupyter notebooks and Wakis' satellite packages, use:

pip install wakis['all']

GPU execution also requires a CuPy build compatible with your CUDA or ROCm installation, and MPI execution requires mpi4py plus an MPI runtime. See the GPU and MPI installation instructions before running those examples.

To install Wakis from the source, clone the repository and install it in editable mode:

git clone https://github.com/ImpedanCEI/wakis.git
cd wakis
pip install -e .

Install via Docker

A pre-built Docker image of Wakis is available for easy setup and reproducibility.

sudo docker pull docker.io/edelafue/wakis:latest
sudo docker run --rm -it docker.io/edelafue/wakis:latest /bin/bash

💡 Have a bug, feature request, or suggestion? Open a GitHub Issue so the community can track it.

🛠️ Want to contribute? To merge your changes into main, create a Pull Request (PR) following our PR template.

Motivation

🎯 The determination of electromagnetic wakefields and their impact on accelerator performance is a significant issue in current accelerator components. These wakefields, which are generated within the accelerator vacuum chamber as a result of the interaction between the structure and a passing beam, can have significant effects on the machine. These effects can be characterized through the beam coupling impedance in the frequency domain and wake potential in the time domain. Accurate evaluation of these properties is essential for predicting dissipated power and maintaining beam stability. wakis is an open-source tool that can compute wake potential and impedance for both longitudinal and transverse planes for general 3D structures.

• 🌱 wakis was firstly presented at the International Particle Accelerator Conference in 2023 (IPAC23) as a post-processing tool: https://doi.org/10.18429/JACoW-IPAC2023-WEPL170

• 🌳 It has now evolved from a post-processing tool to a full 3D electromagnetic, time domain solver; and has been presented at the ICAP24: The 14th International Computational Accelerator Physics Conference in 2024: https://indico.gsi.de/event/19249/contributions/82636/

• 🌸 A dedicated contribution was presented at IPAC'25: The 16th International Particle Accelerator Conference: https://inspirehep.net/literature/3101186

Citing Wakis

🔖 Each Wakis release is archived on Zenodo with a version-specific DOI. For a citation that points to the latest archived version, use the concept DOI:

E. de la Fuente Garcia et al., “Wakis”. Zenodo. https://doi.org/10.5281/zenodo.14988676

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