⚛️ Gas Time-Projection Chamber: Electron Drift, Diffusion, Gain and Track Reconstruction (2D side view)

Side view of a gas time-projection chamber. A particle ionises the gas, the electrons drift to the readout plane under the electric field, spread by diffusion and are amplified, and the arrival times rebuild the height of every point on the track. Set field, drift length, gain, diffusion and track ionisation. The 3D cutaway has field, drift and gain sliders; this page gives them real units, with four in-page numerical checks.