Scintillator-based transition radiation detectors for very high-energy particles

The use of relatively thick foils, large spacings, and high plasma frequencies makes it possible to extend the energy range of transition radiation detectors up to Lorentz factors near 105. The maximum sensitivity to particle energy then comes at frequencies above 100 keV, where inorganic scintillators are effective X-ray detectors and Compton scattering can be used to separate the X-ray signal from the particleʹs ionization. We describe the motivation and use of scintillator-based detectors to measure particle energies.