title: Characterization of a multi-axis ion chamber array.
abstract: OBJECTIVE
  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 approximately 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.
authors.affiliation: Department of Nuclear and Radiological Engineering, University of Florida, 202 Nuclear Science Building, Gainesville, Florida 32611-8300, USA.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Simon
authors.forename: Jakub
authors.initials: J
authors.lastname: Kozelka
authors.forename: William E
authors.initials: WE
authors.lastname: Simon
authors.forename: Darren
authors.initials: D
authors.lastname: Kahler
authors.forename: Jonathan
authors.initials: J
authors.lastname: Li
authors.forename: Chihray
authors.initials: C
authors.lastname: Liu
mesh_terms: D000465:Algorithms; D002138:Calibration; D004581:Electronics; D004867:Equipment Design; D007477:Ions; D010315:Particle Accelerators; D019047:Phantoms, Imaging; D011786:Quality Control; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results; D014867:Water / Q000737:chemistry
chemical_list: D007477:Ions; D014867:Water