Run the Hoffart diocotron case

The Hoffart diocotron case lives in adc_cases. It reproduces the diocotron instability benchmark of Hoffart et al. (arXiv:2510.11808, Sec 5.3) with the DSL path.

Prerequisites

• The pops Python module, built from adc_cpp. See Installation.

• A local clone of adc_cases.

Run it

1. Clone adc_cases and enter the case folder:

   git clone https://github.com/wolf75222/adc_cases.git
   cd adc_cases/hoffart_euler_poisson_dsl
   

2. Run the case:

   python run.py
   

   The script advances the diocotron instability and writes its figures (snapshots, growth rate) to the case folder. The case provides a reduced or quick mode for a fast first run; see its README.

What it demonstrates

A neutralizing-background density in an annulus, perturbed by an azimuthal mode l, drifts under the ExB velocity and grows at a mode-dependent rate. The case measures the growth rate and compares it to the paper target after mapping the fit windows into the solver clock.

Learn more

• The case in adc_cases: hoffart_euler_poisson_dsl.

• The physics: Hyperbolic-elliptic systems and Polar and disc geometry.

• The DSL path: Write a model with the symbolic DSL.