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Characterization of a multi‐axis ion chamber array
Author(s) -
Simon Thomas A.,
Kozelka Jakub,
Simon William E.,
Kahler Darren,
Li Jonathan,
Liu Chihray
Publication year - 2010
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3505452
Subject(s) - dosimetry , linear particle accelerator , materials science , ionization chamber , imaging phantom , backscatter (email) , calibration , beam (structure) , optics , dose profile , flat panel detector , detector , environmental science , nuclear medicine , physics , ion , computer science , telecommunications , medicine , quantum mechanics , wireless , ionization
Purpose: The aim of this work was to characterize a multi‐axis ion chamber array (IC PROFILER™; Sun Nuclear Corporation, Melbourne, FL USA) that has the potential to simplify the acquisition of LINAC beam data. Methods: The IC PROFILER™ (or panel ) measurement response was characterized with respect to radiation beam properties, including dose, dose per pulse, pulse rate frequency (PRF), and energy. Panel properties were also studied, including detector‐calibration stability, power‐on time, backscatter dependence, and the panel's agreement with water tank measurements [profiles, fractional depth dose (FDD), and output factors]. Results: The panel's relative deviation was typically within (±) 1% of an independent (or nominal) response for all properties that were tested. Notable results were (a) a detectable relative field shape change of ∼ 1 % with linear accelerator PRF changes; (b) a large range in backscatter thickness had a minimal effect on the measured dose distribution (typically less than 1%); (c) the error spread in profile comparison between the panel and scanning water tank (Blue Phantom™, CC13™; IBA Schwarzenbruck, DE) was approximately (±) 0.75%. Conclusions: The ability of the panel to accurately reproduce water tank profiles, FDDs, and output factors is an indication of its abilities as a dosimetry system. The benefits of using the panel versus a scanning water tank are less setup time and less error susceptibility. The same measurements (including device setup and breakdown) for both systems took 180 min with the water tank versus 30 min with the panel. The time‐savings increase as the measurement load is increased.