Presenter of 1 Presentation
Spectral - and intensity-sensitive characterization of pulsed FLASH proton fields with the pixel detector TimePIX3
Abstract
Background and Aims
FLASH radiotherapy requires the development of new detectors to be able to cope with ultra-high-pulse-dose-rates (UHDpulse) beams. This work aims to test customized Timepix3 detectors to identify the most suitable sensor and settings to be used for the characterization of stray radiation produced in UHDpulse proton beams (PB).
Methods
Dose rates (DR) exceeding 160Gy/s were delivered by a pencil proton beam of 220MeV energy at the University Proton Therapy Dresden, Germany. For data collection two customized semiconductor pixel detectors, Timepix3 ASIC chip, with electronics placed on a flexible cable (50mm distance from the sensor, Fig. 1) were immersed, in turns, inside a water-phantom. The detectors were moved laterally at different depth during irradiation.
Figure 1. Experimental setup with Minipix-Timepix3-Flex detector placed in a waterproof cadge.
Results
The Minipix-Timepix3-Flex detector (Fig. 1) provides ns timing resolution at the pixel level together with quantum-imaging sensitivity with 100% detection efficiency for heavy-charged particles. The integrated per-pixel deposited energy, number of registered events, and DR were measured (Fig. 2).
Figure 2. The plots show the spatial distribution of integrated deposited energy at 50mm (left) and 100mm (right) behind Bragg Peak for a 2ms proton pulse measured with Minipix-Timepix3 with 100µm (top) and 650µm (bottom) thick silicon sensor.
Conclusions
A detector equipped with a thinner silicon sensor, 100µm, is more suitable for UHDpulse PB measurements due to the reduced amplitude of the signal and pixel size, allowing to register higher event rates.
Acknowledgements: This work was supported by the 18HLT04UHDpulse project founded by EMPIR-programme and EU INSPIRE (730983) project.
Author Of 2 Presentations
OVERVIEW AND CURRENT STATUS OF THE JOINT RESEARCH PROJECT UHDPULSE - “METROLOGY FOR ADVANCED RADIOTHERAPY USING PARTICLE BEAMS WITH ULTRA-HIGH PULSE DOSE RATES”
Abstract
Background and Aims
Dosimetry for FLASH radiotherapy, VHEE radiotherapy as well as for laser-driven beams cause significant metrological challenges due to the ultra-high dose rates and pulsed structure of these beams, in particular for real time measurements with active dosimeters. It is not possible to simply apply existing Codes of Practice available for dosimetry in conventional external radiotherapy here. However, reliable standardized dosimetry is necessary for accurate comparisons in radiobiological experiments, to compare the efficacy of these new radiotherapy techniques and to enable safe clinical application. UHDpulse aims to develop the metrological tools needed for reliable real-time absorbed dose measurements of electron and proton beams with ultra-high dose rate, ultra-high dose per pulse or ultra-short pulse duration.
Methods
Within UHDpulse, primary and secondary absorbed dose standards and reference dosimetry methods are developed, the responses of available state-of-the-art detector systems are characterised, novel and custom-built active dosimetric systems and beam monitoring systems are designed, and methods for relative dosimetry and for the characterization of stray radiation are investigated.
Results
Prototypes of different active dosimetry systems show promising results for real-time dosimetry for particle beams with ultra-high pulse dose rates. The results of the UHDpulse project will be the input data for future Codes of Practice.
Conclusions
A brief overview of the progress in the UHDpulse project and the involved institutions will be given.
Acknowledgement: This project 18HLT04 UHDpulse has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.
Spectral - and intensity-sensitive characterization of pulsed FLASH proton fields with the pixel detector TimePIX3
Abstract
Background and Aims
FLASH radiotherapy requires the development of new detectors to be able to cope with ultra-high-pulse-dose-rates (UHDpulse) beams. This work aims to test customized Timepix3 detectors to identify the most suitable sensor and settings to be used for the characterization of stray radiation produced in UHDpulse proton beams (PB).
Methods
Dose rates (DR) exceeding 160Gy/s were delivered by a pencil proton beam of 220MeV energy at the University Proton Therapy Dresden, Germany. For data collection two customized semiconductor pixel detectors, Timepix3 ASIC chip, with electronics placed on a flexible cable (50mm distance from the sensor, Fig. 1) were immersed, in turns, inside a water-phantom. The detectors were moved laterally at different depth during irradiation.
Figure 1. Experimental setup with Minipix-Timepix3-Flex detector placed in a waterproof cadge.
Results
The Minipix-Timepix3-Flex detector (Fig. 1) provides ns timing resolution at the pixel level together with quantum-imaging sensitivity with 100% detection efficiency for heavy-charged particles. The integrated per-pixel deposited energy, number of registered events, and DR were measured (Fig. 2).
Figure 2. The plots show the spatial distribution of integrated deposited energy at 50mm (left) and 100mm (right) behind Bragg Peak for a 2ms proton pulse measured with Minipix-Timepix3 with 100µm (top) and 650µm (bottom) thick silicon sensor.
Conclusions
A detector equipped with a thinner silicon sensor, 100µm, is more suitable for UHDpulse PB measurements due to the reduced amplitude of the signal and pixel size, allowing to register higher event rates.
Acknowledgements: This work was supported by the 18HLT04UHDpulse project founded by EMPIR-programme and EU INSPIRE (730983) project.