A5012196215- Radiation Detection and Scintillator Technologies
- Radiation Therapy and Dosimetry
- Advanced Radiotherapy Techniques
- Radiation Effects in Electronics
- Medical Imaging Techniques and Applications
- Nuclear Physics and Applications
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Advanced X-ray and CT Imaging
- Quantum Chromodynamics and Particle Interactions
- Radiation Effects and Dosimetry
- Radiation Dose and Imaging
- High-Energy Particle Collisions Research
- Graphite, nuclear technology, radiation studies
- Neural Networks and Applications
- Atomic and Subatomic Physics Research
- CCD and CMOS Imaging Sensors
- Gear and Bearing Dynamics Analysis
- Mathematical Biology Tumor Growth
- Black Holes and Theoretical Physics
- Plasma Diagnostics and Applications
- Electron and X-Ray Spectroscopy Techniques
- Nuclear reactor physics and engineering
- Analytical chemistry methods development
- VLSI and Analog Circuit Testing
Universidade de Santiago de Compostela
2013-2024
Instituto de Investigación Sanitaria de Santiago
2015-2021
Complexo Hospitalario Universitario A Coruña
2018
Universidad de Murcia
2016
University of Cyprus
2015
Hospital Montecelo
2012
Max Planck Institute for Nuclear Physics
2012
Hospital General Universitario De Valencia
2012
University of New Mexico
2012
University Hospital Heidelberg
2012
UHDpulse – Metrology for advanced radiotherapy using particle beams with ultra-high pulse dose rates is a recently started European Joint Research Project the aim to develop and improve dosimetry standards FLASH radiotherapy, very high energy electron (VHEE) laser-driven medical accelerators. This paper gives short overview about current state of developments electrons protons, as well particles related challenges in due rate during radiation pulses. We summarize objectives plans project...
Conventional air ionization chambers (ICs) exhibit ion recombination correction factors that deviate substantially from unity when irradiated with dose per pulse magnitudes higher than those used in conventional radiotherapy. This fact makes these devices unsuitable for the dosimetric characterization of beams ultra-high as FLASH radiotherapy.We present design, development, and an ultra-thin parallel plate IC can be rate (UHDR) deliveries minimal recombination.The charge collection...
Neutron production in radiotherapy facilities has been studied from the early days of modern linacs. Detailed studies are now possible using photoneutron capabilities general-purpose Monte Carlo codes at energies interest medical physics. The present work effects modelling different accelerator head and room geometries on neutron fluence spectra predicted via Carlo. results simulation a 15 MV Siemens PRIMUS linac show an 80% increase scored isocentre when, besides components neccessary for...
The goal of the DIRAC experiment at CERN (PS212) is to measure $\pi^+\pi^-$ atom lifetime with 10% precision. Such a measurement would yield precision 5% on value $S$-wave $\pi\pi$ scattering lengths combination $|a_0-a_2|$. Based part collected data we present first result lifetime, $\tau=[2.91 ^{+0.49}_{-0.62}]\times 10^{-15}$ s, and discuss major systematic errors. This corresponds $|a_0-a_2|=0.264 ^{+0.033}_{-0.020} m_{\pi}^{-1}$.
In this work, we have investigated the sensitivity of effectiveness (TCP) molecular radiotherapy (MRT) treatment to uncertainties dose rate curves that may appear when reconstructing those curves. We generated different from experimental data, imposing constraint equal for each them. Then, computed TCPs and looked correlations between metrics measuring differences in TCP. Finally, according these results, estimated range tolerable The study was performed radiopharmaceuticals radiosensitive...
We give the complete twisted Yukawa couplings for all Z n orbifold constructions in most general case, i.e. when deformations are considered. This includes a certain number of tasks. Namely, determination allowed couplings, calculation explicit dependence values on moduli expectation (i.e. parameters determining size and shape compactified space), etc. The final expressions completely explicit, which allows counting different each (with without deformations). knowledge is crucial to...
Neutron peripheral contamination in patients undergoing high-energy photon radiotherapy is considered as a risk factor for secondary cancer induction. Organ-specific neutron-equivalent dose estimation therefore essential reasonable assessment of these associated risks. This work aimed to develop method estimate doses multiple organs patients. The involved the convolution, at 16 reference points an anthropomorphic phantom, normalized Monte Carlo neutron fluence energy spectra with kerma and...
In order to obtain realistic and reliable Monte Carlo simulations of medical linac photon beams, an accurate determination the parameters that define primary electron beam hits target is a fundamental step. this work we propose new methodology commission beams in ensures reproducibility wide range clinically useful fields. For such purpose accelerated 2 x 2, 10 10, 20 cm2 fields at SSD = 100 cm are carried out for several combinations mean energy radial FWHM. Then, by performing simultaneous...
The DIRAC experiment at CERN has achieved a sizeable production of $\pi^+\pi^-$ atoms and significantly improved the precision on its lifetime determination. From sample 21227 atomic pairs, 4% measurement S-wave $\pi\pi$ scattering length difference $|a_0-a_2| = (.0.2533^{+0.0080}_{-0.0078}|_\mathrm{stat}.{}^{+0.0078}_{-0.0073}|_\mathrm{syst})M_{\pi^+}^{-1}$ been attained, providing an important test Chiral Perturbation Theory.
An accurate computation of the collection efficiency due to recombination has a capital importance in order perform high-precision dose measurements with ionization chambers. The two-voltage method, developed compute charge gas chambers, cannot be directly applied liquid-filled chambers (LICs) ionized strong dependence on electric field, which is caused by initial recombination. It shown that apply method parallel-plate LICs it necessary introduce explicitly slope yield respect polarization...
This work focuses on neutron monitoring at clinical linac facilities during high-energy modality radiotherapy treatments. Active in-room measurement of fluence is a complex problem due to the pulsed nature and presence high photon background, only passive methods have been considered reliable until now. In this paper we present new active method perform real-time production around medical linac. The device readout being investigated as an estimate patient dose exposure each session....
This work is devoted to studying the influence of chamber response functions on standard IMRT verification for different detector technologies available commercial devices. We have tested three most used 2D arrays radiotherapy dosimetry verification, based air-ionization chambers and diode detectors. The function has been carefully simulated using Monte Carlo method measured through slit pinhole collimators. Although detectors considerably with respect that diodes, impact a in gamma...
The accurate detection and dosimetry of neutrons in mixed pulsed radiation fields is a demanding instrumental issue with great interest both for the industrial medical communities. In recent studies neutron contamination around linacs, there growing concern about secondary cancer risk radiotherapy patients undergoing treatment photon modalities at energies greater than 6 MV. this work we present promising alternative to standard detectors an active method measure linac using novel ultra-thin...
Abstract Silicon Carbide (SiC) is a radiation hard wide bandgap semiconductor, which makes it an interesting alternative for detector fabrication, with potential applications such as High Energy Physics, synchrotron and radiotherapy instrumentation. In addition, by reducing the amount of metal over active area said detectors (typically used electrical connectivity implant pn-junction) unwanted effects from secondary interactions can affect accuracy measurement be diminished, essential to...
Dosimetry of ultra-high dose rate beams is one the critical components which required for safe implementation FLASH radiotherapy (RT) into clinical practice. In past years several national and international programmes have emerged with aim to address some needs that are translation this modality clinics. These involve establishment dosimetry standards as well validation protocols procedures. This review provides an overview recent developments in field RT, particular focus on primary...
Modern dosimetry protocols are based on the use of ionization chambers provided with a calibration factor in terms absorbed dose to water. The basic formula determine at user's beam contains well-known quality correction that is required whenever radiation used differs from radiation. describe whole chamber procedure and include tabulated factors which refer 60Co gamma as quality. They have been calculated for series qualities formulae, also described protocols. In case high-energy photon...
Purpose: Recently, an international working group on nonstandard fields presented a new formalism for ionization chamber reference dosimetry of small and [Alfonso et al. , Med. Phys. 35 5179–5186 (2008)] which has been adopted by AAPM TG‐148. This work presents experimental determination the correction factors with Exradin A1SL thimble in TomoTherapy unit, focusing on: (i) machine‐specific field, (ii) plan‐class‐specific (iii) two clinical treatments. Methods: Ionization measurements were...
Recombination effects can affect the detectors used for dosimetry of radiotherapy fields. They are important when using ionization chambers, especially in liquid-filled and should be corrected for. The introduction flattening-filter-free accelerators increases typical dose-per-pulse beams, which leads to more recombination effects. Diamond provide a good solution quality assurance small fields, due their low energy dependence volume. group Università di Roma Tor Vergata has developed...
This paper reports on the fabrication, simulation, and charge collection characteristics of a new generation cylindrical silicon microdosimeters fabricated SOI wafers. The devices consist an array p+ electrodes surrounded by trench n+ creating well defined, sensitive volumes. A first batch microsensors with 5.4 μm active thickness has been successfully fabricated. are fully functional good diode behavior depletion voltage only 3 V. Their have investigated using IBIC technique protons alpha...
An architectural performance comparison of bandgap voltage reference variants, designed in a 0.18 μm CMOS process, is performed with respect to single event transients. These are commonly induced microelectronics the space radiation environment. Heavy ion tests (Silicon, Krypton, Xenon) used explore analog single-event transients and have revealed pulse quenching mechanisms analogue circuits. The different topologies compared, terms cross-section, duration amplitude. measured results,...
In this work, we propose a solid-state-detector for use in radiation microdosimetry. This device improves the performance of existing dosimeters using customized 3D-cylindrical microstructures etched inside silicon. The microdosimeter consists an array micro-sensors that have electrodes 15 μm diameter and depth 5 within silicon membrane, resulting well-defined micrometric sensitive volume. These microdetectors been characterized 241Am source to assess their as detectors high-LET environment....