DEVELOPMENT OF A PULSED HIGH-ENERGY PHOTON REFERENCE FIELD FOR TESTING DOSEMETERS USED FOR RADIATION PROTECTION MEASUREMENTS BEHIND SHIELDINGS FROM HIGH ENERGY ACCELERATORS. (February 2022) - Busse, J.; Behrens, R.; Fuente-Rosales, L.; Nettelbeck, H.; Al-Qaaod, A.; Zboril, M.; Zutz, H.; Hupe, O.