Out-of-field measurements and simulations of a proton pencil beam in a wide range of dose rates using a Timepix3 detector: Dose rate, flux and LET

Oancea, Cristina; Granja, Carlos; Marek, Lukáš; Jakůbek, J.; Šolc, J.; Bodenstein, Elisabeth; Gantz, Sebastian; Pawelke, Jörg; Pivec, J.

doi:10.1016/j.ejmp.2023.102529

Cited by 8 publications

(9 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared to the rigid version of the MiniPIX Timepix3 (TPX3) detector (Gohl et al 2022, Granja et al 2022, the customised Flex version has a unique design: the sensor was moved 5 cm away from the electronic components using a flexible printed circuit board (PCB) (Oancea et al 2023). Moreover, to minimize the radiation field perturbation, all metal parts were replaced by plastic and the chip-sensor assembly was placed on an extruded graphite support chiller, see figure 1(a).…”

Section: Instrumentation and Measurementsmentioning

confidence: 99%

“…The detector electronic's component was built into the 3D printed plastic holder, which was designed to facilitate the immersion of the detector under water. The plastic holder was designed to be compatible with the positioning system of the water tank (Oancea et al 2023) to ease the final assembly (figure 1(b)). The holder was placed into a silicon medicinal cover (thickness of 65 μm) for waterproofing purposes.…”

Section: Instrumentation and Measurementsmentioning

confidence: 99%

See 1 more Smart Citation

Thermal neutron detection and track recognition method in reference and out-of-field radiotherapy FLASH electron fields using Timepix3 detectors

Oancea,

Solc,

Bourgouin

et al. 2023

Phys. Med. Biol.

Self Cite

View full text Add to dashboard Cite

Objective. This work presents a method for enhanced detection, imaging, and measurement of the thermal neutron flux. Approach. Measurements were performed in a water tank, while the detector is positioned out-of-field of a 20 MeV ultra-high pulse dose rate electron beam. A semiconductor pixel detector Timepix3 with a silicon sensor partially covered by a 6LiF neutron converter was used to measure the flux, spatial, and time characteristics of the neutron field. To provide absolute measurements of thermal neutron flux, the detection efficiency calibration of the detectors was performed in a reference thermal neutron field. Neutron signals are recognized and discriminated against other particles such as gamma rays and x-rays. This is achieved by the resolving power of the pixel detector using machine learning algorithms and high-resolution pattern recognition analysis of the high-energy tracks created by thermal neutron interactions in the converter. Main results. The resulting thermal neutrons equivalent dose was obtained using conversion factor (2.13(10) pSv·cm2) from thermal neutron fluence to thermal neutron equivalent dose obtained by Monte Carlo simulations. The calibrated detectors were used to characterize scattered radiation created by electron beams. The results at 12.0 cm depth in the beam axis inside of the water for a delivered dose per pulse of 1.85 Gy (pulse length of 2.4 μs) at the reference depth, showed a contribution of flux of 4.07(8) × 103 particles·cm−2·s−1 and equivalent dose of 1.73(3) nSv per pulse, which is lower by ∼9 orders of magnitude than the delivered dose. Significance. The presented methodology for in-water measurements and identification of characteristic thermal neutrons tracks serves for the selective quantification of equivalent dose made by thermal neutrons in out-of-field particle therapy.

show abstract

Section: Instrumentation and Measurementsmentioning

confidence: 99%

Section: Instrumentation and Measurementsmentioning

confidence: 99%

Thermal neutron detection and track recognition method in reference and out-of-field radiotherapy FLASH electron fields using Timepix3 detectors

Oancea,

Solc,

Bourgouin

et al. 2023

Phys. Med. Biol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…These and further steps of data processing are made using the integrated data processing engine (DPE) [20]. Developed by ADVACAM, the DPE tool performs data clustering, applies per-pixel energy calibration, and calculates for each particle track morphological and spectral parameters, including cluster size, length, roundness, deposited energy and LET [4,21,22].…”

Section: Data Processingmentioning

confidence: 99%

“…Timepix detectors are used in a broad range of applications [1,2] ranging from medical imaging, material research to space radiation monitoring [3][4][5][6][7]. These environments are characterised by high-intensity radiation fields that degrade and damage the detectors exposed for an extended period of time.…”

Section: Introductionmentioning

confidence: 99%

Silicon Carbide Timepix3 detector for quantum-imaging detection and spectral tracking of charged particles in wide range of energy and field-of-view

Novak,

Granja,

Sagatova

et al. 2023

J. Inst.

View full text Add to dashboard Cite

The hybrid architecture of the Timepix (TPX) family of detectors enables the use of different semiconductor sensors, most commonly silicon (Si), as well as high-density materials such as Cadmium Telluride (CdTe) or Gallium Arsenide (GaAs). For this purpose, we explore the potential of a silicon carbide (SiC) sensor bump-bonded on a Timepix3 detector as a radiation imaging and particle tracking detector. SiC stands as a radiation-hard material also with the ability to operate at elevated temperatures up to several hundreds of degrees Celsius. As a result, this sensor material is more suitable for radiation harsh environments compared to conventional e.g., Si sensors. In this work, we evaluate the response for precise radiation spectrometry and high-resolution particle tracking of newly developed SiC Timepix3 detector which is built and operated as a compact radiation camera MiniPIX-Timepix3 with integrated readout electronics. Calibration measurements were conducted with mono-energetic proton beams with energies of 13, 22, and 31 MeV at the U-120M cyclotron at the Nuclear Physics Institute Czech Academy of Science (NPI CAS), Prague, as well as 100 and 226 MeV at the Proton Therapy Center Czech (PTC) in Prague. High-resolution pattern recognition analysis and single-particle spectral tracking are used for detailed inspection and understanding of the sensor response. Results include distributions of deposited energy and linear energy transfer (LET) spectra. The spatial uniformity of the pixelated detector response is examined in terms of homogeneously distributed deposited energy.

show abstract

“…Similarly, from a dosimetric point of view, L Δ,,D has been considered as a better parameter to describe the response of different dosimeters [7][8] . In radiotherapy with protons, research has been made to investigate not only the absorbed dose outside of the eld [9][10] but also the L Δ,,D distribution in organs at risk close the tumour volume [11][12] .…”

Section: Introductionmentioning

confidence: 99%

Linear energy transfer (LET) distribution outside small radiotherapy field edges produced by 6 MV X-rays

Huerta-Juan

Xicohténcatl-Hernández

Massillon‐JL

2023

Preprint

View full text Add to dashboard Cite

In modern radiotherapy with photons, the absorbed dose outside the radiation field is generally investigated. But it is well known that the biological damage depends not only on the absorbed dose but also on LET. This work investigated the dose-average LET (L,D) outside several small radiotherapy fields to provide information that can help for better evaluating the biological effect in organs at risk close to the tumour volume. The electron fluences produced in liquid water by a 6 MV X-rays Varian iX linac were calculated using EGSnrc Monte Carlo code. With the electron spectra, L,D calculations were made for eight open small square fields and the reference field at a water depth of 0.15 cm, 1.35 cm, 9.85 cm and 19.85 cm and several off-axis distances. The variation of L,D from the centre of the beam to 2 cm outside the field’s edge depends on the field size and water depth. Using radiobiological data reported in the literature for chromosomal aberrations as endpoint for the induction of dicentrics determined in human Lymphocytes, we estimated the maximum low-dose RBEM finding an increase of up to 100 % from the center of the beam to 2 cm from the field’s edge.

show abstract

Out-of-field measurements and simulations of a proton pencil beam in a wide range of dose rates using a Timepix3 detector: Dose rate, flux and LET

Cited by 8 publications

References 48 publications

Thermal neutron detection and track recognition method in reference and out-of-field radiotherapy FLASH electron fields using Timepix3 detectors

Thermal neutron detection and track recognition method in reference and out-of-field radiotherapy FLASH electron fields using Timepix3 detectors

Silicon Carbide Timepix3 detector for quantum-imaging detection and spectral tracking of charged particles in wide range of energy and field-of-view

Linear energy transfer (LET) distribution outside small radiotherapy field edges produced by 6 MV X-rays

Contact Info

Product

Resources

About