Design and characterization of the beam monitor detectors of the Italian National Center of Oncological Hadron-therapy (CNAO)

Autor: Cristiana Peroni, M. A. Garella, Vincenzo Monaco, M. Mucchi, M. Scalise, Roberto Cirio, Abdolkazem Ansarinejad, G. Alampi, Simona Giordanengo, M. Donetti, I. A. Pecka, Flavio Marchetto, Roberto Sacchi, Caterina Tomba
Přispěvatelé: Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Elsevier, 2013, 698, pp.202-207. ⟨10.1016/j.nima.2012.10.004⟩
ISSN: 0168-9002
DOI: 10.1016/j.nima.2012.10.004⟩
Popis: A new hadron-therapy facility implementing an active beam scanning technique has been developed at the Italian National Center of Oncological Hadron-therapy (CNAO). This paper presents the design and the characterization of the beam monitor detectors developed for the on-line monitoring and control of the dose delivered during a treatment at CNAO. The detectors are based on five parallel-plate transmission ionization chambers with either a single large electrode or electrodes segmented in 128 strips (strip chambers) and 32×32 pixels (pixel chamber). The detectors are arranged in two independent boxes with an active area larger than 200×200 mm 2 and a total water equivalent thickness along the beam path of about 0.9 mm. A custom front-end chip with 64 channels converts the integrated ionization channels without dead-time. The detectors were tested at the clinical proton beam facility of the Paul Scherrer Institut (PSI) which implements a spot scanning technique, each spot being characterized by a predefined number of protons delivered with a pencil beam in a specified point of the irradiation field. The short-term instability was measured by delivering several identical spots in a time interval of few tenths of seconds and is found to be lower than 0.3%. The non-uniformity, measured by delivering sequences of spots in different points of the detector surface, results to be lower than 1% in the single electrode chambers and lower than 1.5% in the strip and pixel chambers, reducing to less than 0.5% and 1% in the restricted 100×100 mm 2 central area of the detector.
Databáze: OpenAIRE