Comparison of air kerma length measurements for CT diagnostic X-ray beam qualities

Project Description

The objective of this comparison is to support the IAEA CMCs for diagnostic calibration of ionization chambers used in computed tomography in terms of air kerma length. For this purpose an indirect comparison is proposed between the air kerma standards of the IAEA and the PTB in the diagnostic x-ray range from 100 kV to 150 kV, using as the transfer instrument a cylindrical pencil ionization chamber, the Extradin Model A101 CT belonging to the IAEA. The standard radiation qualities RQT 8, RQT 9 and RQT10 (according to the IEC 61267:2005) are selected for the comparison. The air kerma standards of the IAEA are traceable to the primary standards of the PTB, therefore uncertainty of the comparison will be reduced, which will allow to validate the partial irradiation method applied at both laboratories for the pencil chamber calibrations according to the IAEA Code of Practice TRS-457.

Final Report 2014-08-01

The comparison has been completed and the results are published in the KCDB.