Functionality and dose determination

When exposed to ionizing radiation, free pairs of charge carriers(electrons and holes) are generated in a crystal and become trapped in crystalline vacancies. Heating frees them from these energetically higher and long-lived states and they recombine emitting light (thermoluminescence, TL for short). The light intensity is a direct measure of the irradiated dose. By enrichment with neutron-sensitive isotopes (e.g. Li-6), the crystal can also be sensitized to thermal neutrons.

Das Zweikomponenten-Albedodosimeter enthält zwei TL-Detektorpaare, wovon das erste die vom Körper zurückgestreuten Neutronen (Albedo-Neutronen) und das zweite die auf den Körper einfallenden thermischen Neutronen (Feldneutronen) misst. Die Angabe der Neutronenäquivalentdosis erfolgt aus der Anzeige des Albedodetektorpaares und dem entsprechenden Kalibrierfaktor für den jeweiligen Anwendungsbereich.

Each detector pair consists of a photon sensitive detector and a photon and neutron sensitive detector. The photon-sensitive detector only is used to determine the respective photon dose. The difference between the two detectors is used to determine the respective neutron fraction. The ratio of field to albedo neutrons provides an additional energy correction factor (DIN 6802-4).

The albedo dosimeter can also be used at high-energy accelerators, since the neutron radiation field at these workplaces always has a proportion of scattered neutrons with low energy and thus a signal sufficient for dose determination is generated in the detector. This could be verified by measurements at different high-energy accelerators.