Sensitive element for ionising radiations - in particular in radio-photoluminescent glass for dosimeters

摘要

The element sensitive to ionising rays is surrounded by a material which simultaneously satisfies the conditions that it is not modified by the ionising rays, it attains electronic equilibrium within a short length and it is transparent to rays of wave-lengths between 250 and 3000 nm. Pref. the material forms an absorbant medium for beta rays such as pure silica. Pref. the sensitive element is partly surrounded by the material at least on the face receiving the excitation rays pref. ultraviolet rays. On the face opposite this receiving face is deposited a reflection system to reflect onto the exit face, the escaping rays. A pref. form uses a radiophotoluminescent glass in the form of a cylindrical rod with a circular section with the excitation rays incident laterally. The rod is deposited in a bore in a parallelepiped and sheets of 1mm thickness are attached to the faces of the rod. Opposite to the front face of the rod is placed a mirror and objecting lens to focus the stimulated rays produced by the rod and leaving by the front face. Used in dosimeters. The use of radio-photoluminescent glass gives results of measurement with a dosimeter which are reproducible and stable with respect to time.