01 Characterization of NIS X-ray machine for Dosimetry in diagnostic application

The international protocols addressed finite beam qualities for each type of diagnostic radiology such as conventional, fluoroscopy, computed tomography and mammography. Moreover, for the dosimetry of each type in diagnostic radiology a certain ion chamber is used. In this work a set of X-ray beam qualities were established in accordance with the Technical Report Series (TRS) No.457-2007 of the International Atomic Energy Agency (IAEA). At the Ionizing Radiation Metrology Laboratory (IRML) of the National Institute of Standards (NIS), traceability is established for a set of ion chambers at the recommended beam qualities, ensuring dosimetry traceability to SI units through calibrations performed at the International Bureau of Weights and Measures (BIPM). The remaining ion chambers were calibrated locally at IRML-NIS. Two X-ray beam qualities were established for fluoroscopy and radiographic applications called RQR5 and RQR8. Moreover, three beam qualities were established for Computed Topography (CT) applications called RQT 8, 9 and 10. In mammography application, only one beam quality was validated by adding Mo filter with Half Value Layer (HVL) of 0.36 mm Al at 18 kV.