Personal Dosimetry in Direct Pulsed Photon Fields With the Dosepix Detector

First investigations regarding dosimetric properties of the hybrid, pixelated, photon-counting Dosepix detector in the direct beam of a pulsed photon field (RQR8) for the personal dose equivalent <inline-formula> <tex-math notation="LaTeX">$H\mathrm {_{p}(10)}$ </tex-math></inline-formula> are presented. The influence quantities such as pulse duration and dose rate were varied, and their responses were compared to the legal limits provided in PTB-A 23.2. The variation of pulse duration at a nearly constant dose rate of about 3.7 Sv/h shows a flat response around 1.0 from 3.6 s down to 2 ms. A response close to 1.0 is achieved for dose rates from 0.07 to 35 Sv/h for both pixel sizes. Above this dose rate, the large pixels (<inline-formula> <tex-math notation="LaTeX">$220~\mu \text{m}$ </tex-math></inline-formula> edge length) are below the lower limit. The small pixels (<inline-formula> <tex-math notation="LaTeX">$55~\mu \text{m}$ </tex-math></inline-formula> edge length) stay within limits up to 704 Sv/h. The count rate linearity is compared to previous results, confirming the saturating count rate for high dose rates.