Problems encountered with a radiation field analyzer.
Isodose measurements of 4-MV beams obtained with a Therados radiation field analyzer were found to vary significantly with the types of detector used, viz., a Physikalisch-Technische Werkstatten (PTW) ion chamber with positive and negative collecting potentials and a Therados diode detector. Suitable means of minimizing the ion chamber polarity effect are described.
D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000295:instrumentation