July 2026 performance highlights across WarpX repos (EZoni/WarpX and ECP-WarpX/WarpX) focused on strengthening physics fidelity, stability, and performance, with clear business value for high-fidelity simulations and scalable deployment. Key features delivered - EZoni/WarpX: DSMC Collision Physics Modernization and Boundary Handling. Refactored SplitAndScatterFunc to build and use ScatteringProcess::Executor, unifying DSMC and MCC scattering and enabling per-process energy penalties. This aligns DSMC with the MCC code path and simplifies access to reaction energy and scattering models. Added support for excitation processes in DSMC and introduced per-process scattering angle models for greater flexibility and realism. Commits include a673da4e68164993e9a5771f04a2533423ae515e, a124dbe566be13503172dd27f51367509a8d4197, 71b07d0eec80edbd71d16fa1611bb1a7ba44563e, 6c04a74dc578ab43a908fd0e859cd6c47c44d610, and 7ebf62c01fd871b4bbc7e4c899a1198e9ecae40d. - EZoni/WarpX: Redistribution fix after beam-size effect. Ensured virtual photons are redistributed to the correct tile box after generation, improving collision kernel correctness with the beam-size feature. Commit 7ebf62c01fd871b4bbc7e4c899a1198e9ecae40d. - EZoni/WarpX: Embedded boundary reflection. Implemented specular reflection from embedded boundaries (new boundary condition) and extended updater and boundary handling to support the Reflect operation. Commit 6c04a74dc578ab43a908fd0e859cd6c47c44d610. - ECP-WarpX/WarpX: Non-uniform spacing support for cross-section energy grid in DSMC/MCC collisions. Added amrex::bisect-based bracketing for energy grids, enabling non-uniform spacing and requiring strictly increasing energy values. Updated getCrossSection to use bisect, updated sanity checks, and aligned device-side storage and documentation. Commit 9371bb18bb056529c408e0381340075e872ec0c. - Bug fixes - Linear Compton: fixed a sampling formula typo in Klein-Nishina implementation (#7029), improving sampling efficiency and correctness. Commit 4f2584acccdd7e414734a24ec6265eb7e2362059. - RSPHERE: corrected polar angle convention by fixing atan2 argument order to match SetParticlePosition, ensuring consistent angle definitions. Commit 2b39ebe68e9906e51340ae20b0cd5f7c18be91bc. Overall impact and accomplishments - Physics fidelity and consistency: DSMC and MCC scattering are now unified under a single per-process executor, enabling excitation processes and more accurate energy accounting across collision types. - Simulation realism: Introduced excitation processes in DSMC and per-process angle models, plus EB reflection, broadening the range of physical scenarios that can be simulated accurately. - Data integrity and stability: Beam-size redistribution fix and boundary handling improvements reduce timestep/box misalignment and simulation artifacts, contributing to more robust runs. - Grid flexibility and performance: Non-uniform energy grids for cross-sections provide better data usage and enable more realistic energy sampling without imposing uniform spacing constraints. - CI and testing: Ongoing improvements to CI/test stability and performance, with more representative benchmarks and faster feedback loops. Technologies/skills demonstrated - GPU-enabled kernel refactoring (SplitAndScatterFunc) and device-side data structures (ScatteringProcess::Executor). - Amrex bisect-based search for non-uniform energy grids and strict grid validation. - Robust boundary condition implementation (embedded boundaries, reflection) and extended boundary scrapers/readout. - Rigorous regression fixes in Compton sampling and coordinate conventions to ensure correctness across physics modules. Notes: All changes were implemented with careful attention to code maintainability and alignment with MCC workflows, aiming to reduce divergence between DSMC and MCC paths while enabling advanced physics and boundary capabilities for production simulations.

June 2026 monthly summary focusing on key accomplishments across two WarpX repositories. Delivered a reliability-focused test fix for 3D initial distribution and introduced a physics-consistent DSMC electron impact ionization model, with CI/test updates to support the changes. The work enhances result fidelity, stability, and maintainability, supporting more trustworthy simulations for design and research teams.

May 2026 (EZoni/WarpX) monthly summary focusing on physics fidelity, solver correctness, and code quality. Delivered targeted features and fixes that improve simulation accuracy in strongly magnetized regimes, ensured energy-momentum conservation in collision ionization, and strengthened documentation and tests to support long-term maintainability and onboarding.

EZoni/WarpX – Monthly summary for 2026-04. Delivered physics-aligned simulation timing configurability, strengthened test infrastructure, and user-facing branding resources. Significant codebase improvements focused on maintainability, accuracy, and business value for users running high-fidelity PIC simulations.

March 2026 performance overview across EZoni/WarpX and ECP-WarpX/WarpX. Focused on delivering business-value through documentation and AI-assisted tooling, physics correctness, and maintainability enhancements. Key outcomes include consolidated user-facing docs with AI-assisted updates, relativistic accuracy fixes in particle handling, and broad codebase maintenance improving stability and future readiness across AMReX integration.

February 2026: Focused on stabilizing the Hybrid PIC workflow in WarpX. Delivered a targeted bug fix to align the Hybrid PIC substep definition with user expectations and enforce an even number of field updates per substep, improving simulation stability and reliability for production workloads. This work was tracked in the ECP-WarpX/WarpX repository and aligns with ongoing improvements under issue/PR #6556.

January 2026 (Month: 2026-01) focused on stabilizing and documenting WarpX workflows in EZoni/WarpX. Key outcomes include a robust Cursor tool test environment on macOS by ensuring correct Python executable resolution in CTest and enforcing use of the conda Python environment to prevent missing packages like numpy and yt; and substantial documentation enhancements to improve scientific usability and reproducibility. These efforts reduce CI failures, simplify onboarding for new contributors, and strengthen the technical foundation for WarpX users.

December 2025 monthly summary for EZoni/WarpX: Mesh Refinement Testing Enhancements delivered, expanding validation coverage for mesh refinement (MR) with two levels, updating documentation to reflect relaxed maximum MR level limit, and introducing new test cases and input parameters. Commit 2fd719c953ff281b50f9f4b823703e66c4aa37d1 added the MR test.

November 2025 monthly summary for EZoni/WarpX focused on delivering a more robust and user-friendly particle data workflow, strengthening CI reliability, and improving maintainability through documentation refinements.

Month: 2025-10 — Focused on documenting scientific outputs and stabilizing CI for WarpX. Delivered a new publication documentation entry for WarpX plasma physics simulations with complete citation and DOI; stabilized CI by suppressing oneAPI deprecation warnings, reducing build interruptions and enabling smoother PR validation. Result: improved research traceability, faster collaboration, and more reliable automated validation.

Concise monthly summary for 2025-09 highlighting key features delivered, major bugs fixed, and impact across WarpX. Emphasis on business value, reliability, and cross-model reuse.

2025-08 WarpX development monthly summary: stabilizing RZ geometry and strengthening documentation for improved reliability and onboarding.

Month 2025-07: Focused documentation work highlighting WarpX research. Delivered a new Documentation Publication Highlight describing a WarpX paper on simulating Hall thrusters and Monte Carlo collisions. The entry captures bibliographic details (authors, title, journal, volume, issue, pages, year, DOI) to improve discoverability and citation accuracy. Commit reference: 0f67dbc02edf01acf6755b8cc96a68502afab0ff with message 'Add new paper using WarpX for Hall thruster simulations (#5995)'.

June 2025 performance highlights for EZoni/WarpX: Delivered the embedded boundary diagnostic eb_covered for cell-level visualization and analysis; improved DSMC ionization product handling for robust allocation with electron-first ordering; stabilized CI/test pipelines across Windows with sanitizer updates and environments; improved LASY test stability by removing near-zero field checks to reduce cross-compiler checksum failures; updated Nuclear Fusion citation in documentation. Overall impact: enhanced analytical capabilities, more reliable builds and tests, and clearer documentation, driving business value through better observability, robustness, and maintainability.

May 2025 WarpX monthly summary focusing on key accomplishments, with emphasis on physics fidelity, code quality, and documentation. Delivered targeted bug fix for Breit-Wheeler input validation, implemented collision/geometry improvements to enhance robustness and reuse, and updated documentation with new references and highlights.

April 2025 performance summary for EZoni/WarpX focused on delivering two high-value improvements that enhance research reproducibility, flexibility, and documentation. The month emphasized clear publication support and modernized example usage to leverage newer AMReX capabilities, aligning with business value of higher citation readiness and maintainable codebases.

March 2025: EZoni/WarpX delivered codebase modernization, enhanced observability, and automated validation for ionization physics. Key outcomes include deprecating tmp_particle_container usage, adding detailed performance profiling in the binary collision kernel to reveal bottlenecks, and introducing automated ion impact ionization tests with refreshed analysis scripts, CMakeLists, and input configurations. These initiatives reduce technical debt, accelerate performance optimization, and improve physics fidelity, delivering measurable business value and stronger project readiness.

February 2025 (2025-02) monthly summary for EZoni/WarpX. Focused on delivering a targeted API improvement to the particle scraping workflow. The primary feature added a dedicated Python API get_particle_scraped_this_step to fetch particles scraped in the current simulation timestep, replacing direct calls to get_particle_boundary_buffer and removing buffer.clear_buffer() calls in tested examples. This change clarifies data access, reduces risk of interfering with diagnostics, and streamlines downstream analytics. The work aligns with ongoing efforts to simplify diagnostics, improve API ergonomics, and improve reproducibility of simulation results.

January 2025 – EZoni/WarpX monthly summary highlighting delivered features, bug fixes, and impact across embedded boundary (EB) workstreams.

December 2024 monthly summary focusing on key accomplishments for EZoni/WarpX. This period centers on a robustness improvement in the DSMC workflow, addressing misconfigurations that could lead to instability during GPU kernel launches and thereby enhancing simulation reliability for users.

November 2024 performance summary for EZoni/WarpX focused on GPU tooling, dependency management, and user experience improvements. Delivered targeted feature deployment to streamline GPU workflows and a careful bug rollback to avoid user disruption.

Monthly highlights for 2024-10: Delivered Embedded Boundary (EB) injection support in WarpX PICMI interface and fixed EB injection timing to align with plane injection. Implementations include a new parameter warpx_inject_from_embedded_boundary and a corresponding species attribute, along with CI test updates to validate the fix. These changes expand physics capabilities, improve simulation fidelity, and strengthen testing coverage, delivering measurable business value in accuracy and reliability for EB-based workflows.