Introduction
Why Plasma Physics?
Plasma is the fourth state of matter — an ionized gas so hot that electrons have been stripped from atoms, leaving a soup of charged particles governed by electric and magnetic fields. Over 99% of the visible universe is plasma: the Sun, stars, nebulae, and the interstellar medium. On Earth, plasmas are the key to fusion energy, the most promising path to clean, limitless power.
This course implements the core equations of plasma physics in pure Python. No libraries — just the mathematics of magnetized, ionized gases expressed as functions. Each lesson introduces one concept, explains the physics, and asks you to write the formula as code.
You will implement:
- Debye length — how a plasma shields electric fields over microscopic distances
- Plasma frequency — the natural oscillation frequency of electrons in a plasma
- Cyclotron motion — the spiral gyration of charged particles in magnetic fields
- Thermal velocity — the characteristic speed of particles at a given temperature
- Plasma beta — the ratio of thermal to magnetic pressure
- E×B drift — the universal drift of all plasma species in crossed fields
- Magnetic mirror — how converging field lines trap charged particles
- Alfvén speed — the speed of magnetohydrodynamic waves in a plasma
- Bremsstrahlung — radiation emitted as electrons scatter off ions
- Coulomb logarithm — the effective range of Coulomb collisions
- Saha equation — the ionization equilibrium of a plasma in thermal balance
- Langmuir probe — the classic diagnostic for measuring plasma parameters
- Fusion power density — the D-T reaction rate and Lawson criterion
- MHD equilibrium — force balance in z-pinch and theta-pinch configurations
- Spitzer resistivity — the electrical resistivity of a hot plasma