Optimization of Scanning Speed Using a Novel Plastic Scintillation Detector to Achieve Ultrafast Beam Scanning
Abstract
Purpose
To assess the impact of scanning speed on beam data quality using a novel plastic scintillation detector (PSD) compared with conventional methods, with the goal of enabling ultrafast scanning.
Methods
Percentage depth dose (PDD) curves and beam profiles were acquired using conventional beam data acquisition methods and with the new PSD system. For scans acquired with the PSD system, multiple scans were acquired with varying scan speeds. Scans acquired with the PSD were compared to those of conventional methods to evaluate the impact of PSD scan speed. Comparisons were performed through visual inspection and gamma passing rates (GPR).
Results
At a scan speed of 1 cm/s, PDDs measured with an ion chamber (IC) and the PSD showed good agreement for a 10x10 cm2 field in a 6X-FFF beam (GPR >95% at 1%/1 mm), with all discrepancies occurring in the shallow buildup region. PDDs acquired with the PSD at 2 and 4 cm/s were similarly consistent, with the 4 cm/s scan completed in half the time (GPR >99% at 2%/1 mm; 8 s acquisition time). At a scan speed of 3 cm/s, the PSD profile closely reproduced a conventional IC profile for a 6E 20x20 cm2 beam, achieving a 100% GPR (2%/1 mm) with a total acquisition time of just 14s.
Conclusion
Beam data acquired using the PSD was able to reproduce that obtained with conventional scanning methods while requiring only a fraction of the acquisition time. These substantial time savings have the potential to significantly reduce the duration of beam scanning tasks such as machine commissioning and annual quality assurance.