Canal-Ray Doppler Spectrometer

Atoms travel along scene positive x. The angle is measured in the laboratory between this velocity and the photon path to the counter. Forward observation shifts the moving line upward in frequency, backward observation downward. At a right angle the retained time-dilation shift is much smaller than the selected linewidth; a visually merged spectrum can give a weak or boundary estimate.

The discharge and perforated cathode show how positive precursors feed a downstream emitting beam. The optical emission model is neutral hydrogen, not a bare proton spectrum. The input is the neutral atom kinetic energy, not a measured discharge voltage. Neutralization and excitation are only indicated, with no collision, charge-exchange or precursor mass-to-charge inference.

A rounded 486.3 nm vacuum wavelength represents an isolated Balmer-like transition, not an isotope or fine-structure centroid. The hydrogen mass is the proton-plus-electron mass with binding mass neglected. The moving line uses exact relativistic Doppler kinematics at the laboratory collection angle. An independent stationary component has a selected fraction of the photons collected in this arm, not a solved discharge population. Beaming and angular throughput are absorbed into that chosen fraction and source rate.

Both components have the selected Gaussian FWHM; there is no velocity distribution or angle acceptance integration. Each spectral channel integrates 0.15 THz. A whole-line reference bypasses the spectral selector along the same optical arm. The counter receives light; the atoms continue to a separate beam stop. The apparatus is schematic and does not reconstruct Stark’s historical tube, plates, data or interpretation of emitting charge states.

Independent Poisson exposures, fixed calibrated background and stable source. No drift, dead time or calibration uncertainty. The source follows the displayed model; successful recovery validates the simulator, not the historical discovery.