A high energy particle beamline is described which is capable of transporting a high intensity electron beam to potentially occupied areas. Ionization chamber measurements of electron beam intensity are described together with the ion chamber calibration and necessary corrections. The results of the measurements are compared with a Monte Carlo calculation of the electron intensity. (Submitted t...

An X-ray calorimeter has been used to determine the to ta l energy t ransported by bremsstrahlung beams with maximum photon energies between 18.2 and 170 Mev. The measurements from two experiments have been used to calibrate an aluminum ionization chamber for routine determinations of to ta l beam energy. The calibrations are compared with calibrations of the same chamber made with a scintillat...

An experimental determination has been made of the perturbation correction to be applied to a graphite cylindrical (thimble type) ionization chamber. The results indicate that the magnitude of this correction increases with depth and is closely related to the size of the cavity. This makes possible the use of such a chamber as an' excellent standard of absorbed dose in graphite for 60Co gamma r...

Proven conventional dosimetry techniques do not provide accuracy and precision in the measurement of inverse planned intensity modulated radiation therapy (IMRT) fields. Dynamic and step-and-shoot multileaf collimation (DMLC/SMLC) challenge current ionization chamber dosimetry practices. Ionization chamber performance in these fields is evaluated for three cylindrical chambers of varying volume...