Pic Code Comparison Workshop

Europe/Copenhagen
Niels Bohr International Academy

Niels Bohr International Academy

Blegdamsvej 17 2100 København Ø Denmark
Jacob Trier Frederiksen (Niels Bohr Institute / Niels Bohr International Academy), Troels Haugbølle (Niels Bohr Institute / Niels Bohr International Academy), Åke Nordlund (Niels Bohr Institute / Niels Bohr International Academy)
Description
The PIC Code Comparison Project emerged from discussions during the 2009 KITP workshop Particle Acceleration in Astrophysical Plasmas. The idea is to agree on a standard set of test setups, and try to run as many codes as possible with them. We will all learn from the exercise, and understand what makes some codes better or worse at certain tests. There now exist many excellent Particle-In-Cell codes in the astrophysical community, but different groups have implemented different field solvers, filtering of currents, interpolation methods, and, fundamentally, different numerical methods. There already exist a vast and classic literature on PIC codes, but most of these tests are concerned about non-relativistic plasma dynamics dynamics, and we therefore feel that there is a need to redo some of this work, with a focus on tests, which are relevant for the astrophysical community. By running the same tests with many different codes we hope to * Get an understanding of what is needed to improve on the stability of the codes for longtime runs; this may to some extend be tested with synthetic benchmarks. Both to check for numerical heating of the particles, and generation of EM-waves with high wave numbers ('Cherenkov radiation') * Understand how different codes compare in real world setups. What is for example the minimal number of skin depths per cell, and particles per cell, which are needed to get a collisionless shock, with the correct jump conditions ? Can useful physics be extracted from such a minimal experiment ? How much better does the resolution have to be, for tracing synthetic radiation, and looking at heating / acceleration in the shock structure ? * Leave a legacy of tests that people who are developing PIC codes can use as the standard benchmark to test against. Before the workshop begins most of the groups who are attending should have run some of the tests, so that we have material to work with. We will focus on getting work done, with only one or two talks per day, and office space for everybody. The workshop is organised by the Computational Astrophysics Group and the Niels Bohr International Academy, and will be held at NBIA at Niels Bohr Institute in Copenhagen. Results from the tests can be uploaded to a wiki, which is hosted here The deadline for registration is March 1. Participation in the workshop is free, and we can offer some financial support for some of the participants. Affordable accommodation possibilities near the Niels Boher Institute can be found on this page .
Participants
  • Dmitriy Kolomiets
  • Felix Spanier
  • Gisela Baumann
  • Jacek Niemiec
  • Jacob Trier Frederiksen
  • Leonid Borodachev
  • Maria Elena Innocenti
  • Mikhail Medvedev
  • Troels Haugboelle
  • Tsunehiko Kato
  • Urs Ganse
  • Åke Nordlund
Support
    • Welcome & practical info -- coffee & breakfast
    • Status: How far are the groups with tests
    • First challenge: The distribution function
    • 12:30
      Lunch
    • Problems caused by the shape factor of particles in PIC simulations:Numerical Cherenkov Radiation
    • Time in the office
    • Discussion of results for the distribution function -- coffee & cookies
    • Second challenge: Warm and Cold beams -- coffee and breakfast
    • Working time at the conference room
    • PIC modeling of Magnetic Turbulence Generated by Streaming Cosmic Rays in the Precursor of Parallel Shocks
    • 12:30
      Lunch
    • Time in the office
    • 15:30
      coffee and cookies
    • Discussion of the beam tests
    • Third challenge: Streaming instability in 2D and 3D -- coffee and breakfast
    • Working time at the conference room
    • Solar Jet PIC simulations
    • 12:30
      Lunch
    • Time in the office
    • 15:30
      coffee and cookies
    • Discussion of the streaming instability tests
    • Fourth challenge: 2D collisionless shock -- coffee and breakfast
    • Working time at the conference room
    • Radiation Spectral Synthesis of Relativistic Filamentation
    • 12:30
      Lunch
    • Time in the office
    • 15:30
      coffee and cookies
    • Discussion of the collisionless shock test
    • coffee and breakfast
    • Wrapup of the tests: What have we learned, and where to go from here
    • 12:30
      Lunch