English Abstract A new dosemeter was developed for environmental
dosimetry to measure the ambient dose equivalent. The dosemeter consists of
a slide containing four CaSO4:Dy pellets and a cilindrical metal filter
filled with polymethylmethacrylate. Metal filters of aluminium, stainless
steel and copper were studied for compensation of the photon energy
dependence of the response of CaSO4:Dy. Three prototype dosemeters were
manufactured based on calculations using mass attenuation coefficients.
However, a disagreement was found between the calculated and measured
response, especially for the aluminium prototype. Therefore additional
calculations of the photon energy dependence were performed using a
Monte-Carlo code. With these calculations it was possible to reproduce the
measured values. On basis of the measurements and the Monte-Carlo
calculations a 2 mm copper filter was recommended.
