4 research outputs found

    Caractérisation du détecteur à fibre scintillante plastique commercial et étude sur la réduction de dose aux appareils cardiaques implantables par blindage de plomb

    Get PDF
    Le rĂ©cent dĂ©veloppement de la mĂ©thode de discrimination spectrale pour la calibration des dosimĂštres Ă  fibres scintillantes plastiques (PSD) a conduit au dĂ©veloppement du premier dosimĂštre commercial de ce type, soit l’Exradin W1 (STANDARD IMAGING INC., Middleton, WI, U.S.). Comme tout nouveau dosimĂštre, celui-ci se devait d’ĂȘtre caractĂ©risĂ© afin d’évaluer sa fiabilitĂ© en conditions standards d’irradiation. Le but premier du projet Ă©tait d’effectuer cette validation. Les rĂ©sultats obtenus ont dĂ©montrĂ© que le dosimĂštre Ă  scintillation Ă©tait un excellent candidat pour rĂ©aliser des mesures de dose hors-champ telles que rencontrĂ©es lors de l’évaluation de la rĂ©duction de dose aux appareils cardiaques implantables (ACI) par blindage. Les mesures effectuĂ©es avec l’Exradin W1 ont dĂ©montrĂ© une importante rĂ©duction de dose autant pour les simples champs antĂ©ro-postĂ©rieurs (de 40 % Ă  80 % de rĂ©duction de dose) que pour les traitements cliniques complexes (entre 5 % et 45 % de rĂ©duction de dose).The recent development of the spectral method for correction of the Cˇ erenkov light in plastic scintillation detectors (PSD) have led to the first commercial dosimeter of this type, the Exradin W1 (STANDARD IMAGING INC., Middleton, WI, U.S.). As any new commercial dosimeter, it had to be characterized and validated in different situations of radiation. The first purpose of this project was to perform this validation. The results of characterization have shown that PSD is an efficient dosimeter to make out-of-field doses measurements as required in the evaluation of the feasibility of using a lead sheet to reduce dose to Cardiac Implantable Electronic Devices, CIED. Measurements performed with PSD shown an important reduction of doses by the shielding for square anterior-posterior field (40 % to 80 %) and also for complex clinical treatments (5 % to 45 %)

    Numerical modeling of air-vented parallel plate ionization chambers for ultra-high dose rate applications

    Get PDF
    Purpose: air-vented ionization chambers have been the secondary standard for radiation dosimetry since the origins of radiation metrology. However, the feasibility of their use in ultra-high dose rate pulsed beams has been a matter of discussion, as large losses are caused by ion recombinations and no suitable theoretical model is available for their correction. The theories developed by Boag and his contemporaries since the 1950s, which have provided the standard ion recombination correction factor in clinical dosimetry, do not provide an accurate description when used under the limit conditions of ultra-high dose rates (UHDRs). Moreover, the high-ion recombination effects of ionization chambers under extreme dose-rate applications are an obstacle to the development of adequate dosimetry standardsThis work has received funding from the EMPIR programme project 18HLT04 UHDpulse co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programmeS
    corecore