The effect of non-ionizing excitations on the diffusion of ion species and inter-track correlations in FLASH ultra-high dose rate radiotherapy

التفاصيل البيبلوغرافية
العنوان: The effect of non-ionizing excitations on the diffusion of ion species and inter-track correlations in FLASH ultra-high dose rate radiotherapy
المؤلفون: Abolfath, Ramin, Baikalov, Alexander, Bartzsch, Stefan, Afshordi, Niayesh, Mohan, Radhe
المصدر: Physics in Medicine & Biology 67, 105005 (2022)
سنة النشر: 2022
المجموعة: Nonlinear Sciences
Physics (Other)
مصطلحات موضوعية: Physics - Medical Physics, Nonlinear Sciences - Chaotic Dynamics
الوصف: We present a microscopic mechanism that accounts for the outward burst of "cold" ion species (IS) in a high-energy particle track due to coupling with ''hot" non-ion species (NIS). IS refers to radiolysis products of ionized molecules, whereas NIS refers to non-ionized excitations of molecules in a medium. The interaction is mediated by a quantized field of acoustic phonons, a channel that allows conversion of thermal energy of NIS to kinetic energy of IS, a flow of heat from the outer to the inner core of the track structure. We demonstrate the coexistence of "hot" NIS with "cold" IS in the radiation track structures right after their generation. NIS, concentrated within nano-scales volumes wrapping around IS, are the main source of intensive heat-waves and the outward burst of IS due to femto-second time scale IS-NIS coupling. By comparing the transport of IS coupled to NIS with identical configurations of non-interacting IS in thermal equilibrium at room temperature, we demonstrate that the energy gain of IS due to the surrounding hot nanoscopic volumes of NIS significantly increases their effective diffusion constants. The much higher diffusion constants predicted in the present model suggest higher inter-track chemical reaction rates at FLASH-UHDR, as well as lower intra-track reaction rates.
نوع الوثيقة: Working Paper
DOI: 10.1088/1361-6560/ac69a6
URL الوصول: http://arxiv.org/abs/2201.07887
رقم الأكسشن: edsarx.2201.07887
قاعدة البيانات: arXiv
الوصف
DOI:10.1088/1361-6560/ac69a6