Mvsrandaz·h point for electron beams with energies of a cylindrical ionization Drataqk different

[摘要] BackgroundandObjective:Inordertomeasuretheabsorbeddoseduetoelectronbeamirradiationatthereferencepointofamedium,partofthismediumisreplacedbyacylindricalionizationchambers.Thuschangeswillappearinattenuationandscatteringoftheradiation.Inordertoassessthedisplacementeffect,aneffectivepointofmeasurementusesasthereferencepoint.Thiseffectivepointistakenupstreamofthegeometricalcenterofthechamber.Thiseffectivepointofmeasurementdependsoneverydetailofthechamberdesign,energyandfieldsize.So,inthedifferentresearchesonthispoint,variousvalueshasbeenreportedforcylindricalionizationchamber.ThepurposeofthisstudywastoanalysethedosimetricinformationofelectronbeamsanddeterminetheanalyticaleffectivepointofmeasurementinCC13ionizationchamber.SubjectsandMethods:InthisstudyaCC13ionizationchamberwasusedfordosedeterminationof9,12and15MeVelectronbeamsofVarianacceleratorofAhwazGolestanhospitalindifferentfieldsizesof6×6cm2upto25×25cm2applicators.Measurementwasmadeinbluephantom,upto30mmdepth.ThePDDcurvewasplottedseparatelyforalltreatmentelectronfields.Thetablecurve2Dsoftwarewasusedforanalyzingexperimentaldata.Thencriticalpointforeachcurvewascalculated.Results:Thetorsionareaiscausedbychangingenvironmentfromairtophantom(water)duringmeasuringofionization.Also,withincreasedenergyandfieldsize,meaneffectivepointofmeasurementisaltered.Conclusion:ForCC13ionizationchamber,themeanvalueisobtainedas0.9r.

[学科分类] 基础医学