CompScatLab is a handy toolkit for anyone working with photon scattering and detectors. Pick an incoming energy and angle to quickly get the scattered photon energy and the recoil electron’s kick. Flip between wavelength, energy, and frequency in a snap, with flexible units for the lab. Check the Klein–Nishina curve to see how likely a photon is to head a certain way. Convert between polar/azimuth angles and the real-world scattering plane so gear lines up right. Run a fast 4-vector check to make sure energy and momentum add up before and after a hit. Estimate blur from many tiny bends in thin stuff to tune beams and improve sharpness. Fit detector channel to energy with simple curves, gauge window loss, and add light binding fixes when needed.