A novel Cherenkov detector, a time-of-propagation (TOP) disc DIRC, is proposed for particle identification at the PANDA experiment at the future FAIR facility. It measures Cherenkov light that is generated and internally reflected in a 2 cm thick fused silica plate. The Cherenkov angle is reconstructed from a time-of-propagation measurement at the rim of the disc of individual Cherenkov photons with a resolution of better than 50 ps. Dichroic mirrors at the rim of the disc fulfil two purposes. They allow for a selection of certain wavelength bands and thus are used to reduce dispersive smearing, and they enlarge the average photon path length by reflection and thus improve the separation power of the detector. A reconstruction algorithm has been developed to assign the detected photons to a given particle trajectory. Using a likelihood method, the algorithm calculates particle type probabilities for each track. The detector is expected to separate pions and kaons up to a momentum of ∼ 4 GeV/c. Additional focussing elements at the rim of the disc are proposed to enhance the signal to background separation of the detector.