Person: Udías Moinelo, José Manuel
Universidad Complutense de Madrid
Faculty / Institute
Estructura de la Materia, Física Térmica y Electrónica
Física Atómica, Molecular y Nuclear
Now showing 1 - 10 of 44
PublicationErratum: Nuclear effects in neutrino and antineutrino charged-current quasielastic scattering at MINERνA kinematics(Amer Physical Soc, 2015-02-11) Megías, G. D.; Ivanov, M. V.; González Jiménez, R.; Caballero, J. A.; Bárbaro, M. B.; Donnelly, T. W.; Udías Moinelo, José Manuel PublicationGlobal relativistic folding optical potential and the relativistic Green's function model(Amer Physical Soc, 2016-07-14) Ivanov, M. V.; Vignote, J. R.; Álvarez Rodríguez, R.; Meucci, A.; Giusti, C.; Udías Moinelo, José ManuelOptical potentials provide critical input for calculations on a wide variety of nuclear reactions, in particular, for neutrino-nucleus reactions, which are of great interest in the light of the new neutrino oscillation experiments. We present the global relativistic folding optical potential (GRFOP) fits to elastic proton scattering data from C-12 nucleus at energies between 20 and 1040 MeV. We estimate observables, such as the differential cross section, the analyzing power, and the spin rotation parameter, in elastic proton scattering within the relativistic impulse approximation. The new GRFOP potential is employed within the relativistic Green's function model for inclusive quasielastic electron scattering and for (anti) neutrino-nucleus scattering at MiniBooNE kinematics. PublicationRealistic spectral function model for charged-current quasielastic-like neutrino and antineutrino scattering cross sections on C-12(American Physical Society, 2019-01-10) Ivanov, M. V; Antonov, A. N.; Megias, G. D.; Caballero, J. A.; Barbaro, M. B.; Amaro, J. E.; Ruiz Simo, I.; Donnelly, T. W.; Udías Moinelo, José ManuelA detailed study of charged current quasielastic neutrino and antineutrino scattering cross sections on a C-12 target with no pions in the final state is presented. The initial nucleus is described by means of a realistic spectral function S(p, epsilon) in which nucleon-nucleon correlations are implemented by using natural orbitals through the Jastrow method. The roles played by these correlations and by final-state interactions are analyzed and discussed. The model also includes the contribution of weak two-body currents in the two-particle two-hole sector, evaluated within a fully relativistic Fermi gas. The theoretical predictions are compared with a large set of experimental data for double-differential, single-differential, and total integrated cross sections measured by the MiniBooNE, MINER nu A, and T2K experiments. Good agreement with experimental data is found over the whole range of neutrino energies. The results are also in global good agreement with the predictions of the superscaling approach, which is based on the analysis of electron-nucleus scattering data, with only a few differences seen at specific kinematics. PublicationProperties of low-lying states in Co-65 from lifetime measurements(American Physical Society, 2019-02-25) Olaizola, B.; Fraile Prieto, Luis Mario; Mach, Henryk Andrzej; Nowacki, F.; Poves, A.; Aprahamian, A.; Briz, J. A.; Cal González, J.; Ghita, D.; Koster, U.; Kurcewicz, W.; Lesher, S. R.; Pauwels, D.; Picado, E.; Radulov, D.; Simpson, G. S.; Udías Moinelo, José ManuelThe low-energy structure of Co-65 was studied by means of gamma(-) and fast-timing spectroscopy at the ISOLDE/CERN facility. The known level scheme of Co-65 populated following the beta(-) decay of Fe-65 was expanded. The experimental results were compared with large-scale shell-model calculations. The measured long lifetime of the (1/2(1)(-)) level confirms its nature as a highly collective state with proton excitations across the Z = 28 gap and neutrons across the N = 40 subshell. PublicationRadical Production with Pulsed Beams: Understanding the Transition to FLASH(MDPI, 2022-11) Espinosa Rodríguez, Andrea; Sánchez Parcerisa, Daniel; Ibáñez García, Paula Beatriz; Antonio Vera Sánchez, Juan; Mazal, Alejandro; Fraile Prieto, Luis Mario; Udías Moinelo, José ManuelUltra-high dose rate (UHDR) irradiation regimes have the potential to spare normal tissue while keeping equivalent tumoricidal capacity than conventional dose rate radiotherapy (CONV-RT). This has been called the FLASH effect. In this work, we present a new simulation framework aiming to study the production of radical species in water and biological media under different irradiation patterns. The chemical stage (heterogeneous phase) is based on a nonlinear reaction-diffusion model, implemented in GPU. After the first 1 mu s, no further radical diffusion is assumed, and radical evolution may be simulated over long periods of hundreds of seconds. Our approach was first validated against previous results in the literature and then employed to assess the influence of different temporal microstructures of dose deposition in the expected biological damage. The variation of the Normal Tissue Complication Probability (NTCP), assuming the model of Labarbe et al., where the integral of the peroxyl radical concentration over time (AUC-ROO) is taken as surrogate for biological damage, is presented for different intra-pulse dose rate and pulse frequency configurations, relevant in the clinical scenario. These simulations yield that overall, mean dose rate and the dose per pulse are the best predictors of biological effects at UHDR. PublicationHigh energy resolution inorganic scintillators read by SiPM arrays(IEEE, 2019) García Díez, Miguel; Sánchez Tembleque, Víctor; Fraile Prieto, Luis Mario; Udías Moinelo, José ManuelThe high energy resolution inorganic scintillators as LaBr3(Ce) have a great importance in the field of nuclear physics and medical applications since they offer great resolution in energy and time. On the other hand, SiPMs are gaining relevance in the fields mentioned above due to its advantages as compact size, invulnerability to magnetic fields, less voltage needed, etc. The goal of this work is to be able to use relatively large scintillators crystals (25,4x25,4 mm cylindrical), for that reason we can't use a single SiPM, because its size is much smaller than the size of the crystal, we use an array of 8x8 SiPMs of 3x3 mm(2) in size from Ketek (model PA3325-WB-0808). With respect to the energy results we obtained the best value using the LaBr3(Ce) (25,4x25,4 mm cylindrical) coupled to the array, providing a resolution of 3,9% (FWHM) for the 661 keV photopeak. For the timing results, we acquired measurements using Co-60 and Na-22 sources and the same LaBr3(Ce) as scintillator crystal. Obtaining coincidence resolving times (FWHM) of 385 ps for Na-22 and 337 ps for Co-60. Para habilitar la compatibilidad con lectores de pantalla, pulsa Ctrl+Alt+Z. Para obtener información acerca de las combinaciones de teclas, pulsa Ctrl+barra diagonal. PublicationRADIANCE-A planning software for intra-operative radiation therapy(Ame Publ CO, 2015-04) Ibáñez García, Paula Beatriz; Vidal, Marie; Udías Moinelo, José ManuelIn the last decades accumulated clinical evidence has proven that intra-operative radiation therapy (IORT) is a very valuable technique. In spite of that, planning technology has not evolved since its conception, being outdated in comparison to current state of the art in other radiotherapy techniques and therefore slowing down the adoption of IORT. RADIANCE is an IORT planning system, CE and FDA certified, developed by a consortium of companies, hospitals and universities to overcome such technological backwardness. RADIANCE provides all basic radiotherapy planning tools which are specifically adapted to IORT. These include, but are not limited to image visualization, contouring, dose calculation algorithms-Pencil Beam (PB) and Monte Carlo (MC), DVH calculation and reporting. Other new tools, such as surgical simulation tools have been developed to deal with specific conditions of the technique. Planning with preoperative images (preplanning) has been evaluated and the validity of the system being proven in terms of documentation, treatment preparation, learning as well as improvement of surgeons/radiation oncologists (ROs) communication process. Preliminary studies on Navigation systems envisage benefits on how the specialist to accurately/safely apply the pre-plan into the treatment, updating the plan as needed. Improvements on the usability of this kind of systems and workflow are needed to make them more practical. Preliminary studies on Intraoperative imaging could provide an improved anatomy for the dose computation, comparing it with the previous pre-plan, although not all devices in the market provide good characteristics to do so. DICOM.RT standard, for radiotherapy information exchange, has been updated to cover IORT particularities and enabling the possibility of dose summation with external radiotherapy. The effect of this planning technology on the global risk of the IORT technique has been assessed and documented as part of a failure mode and effect analysis (FMEA). Having these technological innovations and their clinical evaluation (including risk analysis) we consider that RADIANCE is a very valuable tool to the specialist covering the demands from professional societies (AAPM, ICRU, EURATOM) for current radiotherapy procedures. PublicationPhotoacoustic dose monitoring in clinical high-energy photon beams(IOP Publishing LTD, 2019-04) Giza, Olivia M.; Sánchez Parcerisa, Daniel; Sánchez-Tembleque Verbo, Victor; López Herráiz, Joaquín; Camacho, Jorge; Avery, Stephen; Udías Moinelo, José ManuelThis work describes all stages of development (setup, optimization, performance, and first experimental measurements) of an acoustic sensor that can be used for range monitoring and dosimetry of clinical radiotherapy beams. The detection device consists of an ultrasonic transducer, a combination of preamplifiers and differential amplifiers with filtered outputs and a digital oscilloscope. Simulations of the experimental setup were carried out to study the optimal measurement geometry and choice of transducer. The dose distributions were calculated with the Monte Carlo code FLUKA, while the acoustic simulations were performed with the analytical wave transport code k-Wave. The temporal profiles of the dose pulses, in the order of mu s, were measured with a scintillating crystal coupled to a photomultiplier and used as input for the acoustic simulation. Measurements were performed in a Cyberknife (TM) radiosurgery beam and a TrueBeam unit. A lead block was submerged in water and placed partially or totally in the irradiation field in order to increase the acoustic signal. Photoacoustic signals were detected with both beams with the expected shape and time-delay, after the frequency response of the detection system was taken into account. The proposed setup can detect photoacoustic signals originating from the penumbra of the treatment fields after being processed with the appropriate image analysis tools. PublicationReal-Time 3D PET Image with Pseudoinverse Reconstruction(MDPI, 2020-04-19) López Montes, Alejandro; Galve Lahoz, Pablo; Udías Moinelo, José Manuel; Cal-González, Jacobo; Vaquero, Juan José; Desco, Manuel; López Herraiz, JoaquínReal-time positron emission tomography (PET) may provide information from first-shot images, enable PET-guided biopsies, and allow awake animal studies. Fully-3D iterative reconstructions yield the best images in PET, but they are too slow for real-time imaging. Analytical methods such as Fourier back projection (FBP) are very fast, but yield images of poor quality with artifacts due to noise or data incompleteness. In this work, an image reconstruction based on the pseudoinverse of the system response matrix (SRM) is presented. w. To implement the pseudoinverse method, the reconstruction problem is separated into two stages. First, the axial part of the SRM is pseudo-inverted (PINV) to rebin the 3D data into 2D datasets. Then, the resulting 2D slices can be reconstructed with analytical methods or by applying the pseudoinverse algorithm again. The proposed two-step PINV reconstruction yielded good-quality images at a rate of several frames per second, compatible with real time applications. Furthermore, extremely fast direct PINV reconstruction of projections of the 3D image collapsed along specific directions can be implemented. PublicationInvestigation of Low-lying States in 133Sn Populated in the β Decay of 133In Using Isomer-selective Laser Ionization(Jagiellonian Univ Press, 2018-03) Fraile Prieto, Luis Mario; Benito García, Jaime; Carmona Gallardo, Mariano; Martínez Pérez, Cristina; Sánchez-Tembleque Verbo, Victor; Udías Moinelo, José Manuel; Vedia Fernández, María Victoria; Villa Abaunza, Amaia; otros, ...Excited states in the neutron-rich isotope Sn-133 were studied via the beta decay of In-133. Isomer selective ionization using the ISOLDE RILIS enabled the beta decays of In-133(gs) (I-pi = 9/2(+)) and In-133m (I-pi = 1/2(-)) to be studied independently for the first time. A description of the experimental setup at the ISOLDE Decay Station is presented together with preliminary results from the experiment.