摘要
Extrapolation chambers are instruments designed to measure doses of low-energy radiations, mainly beta radiation. In this work, a commercial extrapolation chamber and a homemade extrapolation chamber were applied in measurements using standard radiotherapy X-ray beams. Saturation curves and polarity effect as well as short- and medium-term stabilities were obtained, and these results are within the recommendations of the International Electrotechnical Commission (IEC). The response linearity and the extrapolation curves were also obtained, and they presented good behavior. The results show the usefulness of these extrapolation chambers in low-energy X-ray beams.