A new pulsed pyroelectric radiation dosimeter.

CARVALHO, A. A.; MASCARENHAS, S.; PAULA, M. H. de

A new pulsed pyroelectric radiation dosimeter.

Autores

CARVALHO, A. A.

MASCARENHAS, S.

PAULA, M. H. de

Descripción

We describe a new type of radiation dosimeter for the diagnostic X-ray region using a pyroelectric detector. The pulsed pyroelectric radiation dosimeter (PPERD) is a system constituted by a X-ray beam commutator, a pyroelectric chamber, a pre-amplifier and an electronic peak detector. The pyroelectric chamber consists basically of a lead zirconium titanate (PZT) ceramic (17mm x 17mm and 3mm thick) on a nylon support. The chamber is evacuated to about 1mm Hg. The thickness of the detector is such that it absorbed more than 99% of the X-ray beam used in these studies. The pyroelectric element itself absorbs a X-ray pulse and provides a voltage proportional to the energy absorbed. The PPERD has the following characteristics for diagnostic X-ray beams: 1) it responds linearly to the radiation intensity for a given radiation spectrum; 2) it responds linearly to the radiatin energy fluence rate; 3) the pyroelectric chamber is simple to construct, inexpensive and rugged; 4) the lower detection limit of energy fluence rate range and of exposure rate range are respectively 20mW/m2 and 9,0.10E-6C.KgE-1 sE-1 (35mR/s).