Extracting W from the electron beam measurements of Domen and Lamperti.

Purpose: The average energy expended by an energetic electron to create an ion pair in dry air, W , is a key quantity in radiation dosimetry. Although W is well established for electron energies up to about 3 MeV, there is limited data for higher energies. The measurements by Domen and Lamperti [Med.

Electron beam water calorimetry measurements to obtain beam quality conversion factors.

Purpose: To provide results of water calorimetry and ion chamber measurements in high-energy electron beams carried out at the National Research Council Canada (NRC). There are three main aspects to this work: (a) investigation of the behavior of ionization chambers in electron beams of different energies with focus on long-term stability, (b) water calorimetry measurements to determine absorbed dose to water in high-energy beams for direct calibration of ion chambers, and (c) using measurements of chamber response relative to reference ion chambers, determination of beam quality conversion factors, k , for several ion chamber types.

Methods: Measurements are made in electron beams with energies between 8 MeV and 22 MeV from the NRC Elekta Precise clinical linear accelerator.