Camilo Ruiz

Universidad de Salamanca

This paper presents a novel target positioner system that exhibits high sensitivity and accuracy. Specifically, the system is capable of precisely locating rough target surfaces within a micron-scale in the focal plane. The high sensitivity comes from the nonlinear detection scheme which uses the two-photon-absorption process in a Si-photodiode and...

We demonstrate that dissociative ionization of H2 can be fully manipulated in an angle-time-resolved fashion, employing a polarization-skewed (PS) laser pulse in which the polarization vector rotates. The leading and falling edges of the PS laser pulse, characterized by unfolded field polarization, trigger, sequentially, parallel and perpendicular...

When a low-power, monochromatic Gaussian beam is focused by a thin lens in air and the waist of the beam is in the plane of the lens, there is a shift of the focus position if the waist of the beam is much smaller than the size of the lens. The point of maximum intensity relative to the geometrical focal point shifts closer to the lens. We show tha...

Purpose This study aims to describe the process leading the climate emergency declaration (CED) at the University of Salamanca. In contrast to similar initiatives, this was achieved with the participation of students on the social movement Fridays For Future Salamanca. Design/methodology/approach The context of the CED is described. Statements in...

Climate Change is one of the greatest challenges for humanity and education plays a fundamental role in raising awareness in society about the importance and need to take adaptation and mitigation measures. Climate Change can be treated from the point of view of education as a competence formed by three dimensions: knowledge, skills and attitudes....

An accurate location of the focal position with respect to a solid target is a key task for different applications, for instance, in laser driven plasma acceleration for x-ray generation where minimum required intensities are above 10 14 W / c m 2 . For such practical applications, new approaches for focus location and target delivery techniques ar...

Purpose – This study aims to introduce a new instrument to assess the perception of the university community after the Climate Emergency Declaration (CED) and its application at the Universidad de Salamanca (USAL) in Spain. This CED includes a comprehensive program to reduce the carbon footprint and the introduction of the education for sustainable...

Non-melanoma skin cancer, and basal cell carcinoma in particular, is one of the most common types of cancer. Although this type of malignancy has lower metastatic rates than other types of skin cancer, its locally destructive nature and the advantages of its timely treatment make early detection vital. The combination of multispectral imaging and a...

Laser–plasma proton sources and their applications to preclinical research has become a very active field of research in recent years. In addition to their small dimensions as compared to classical ion accelerators, they offer the possibility to study the biological effects of ultra-short particle bunches and the correspondingly high dose rates. We...

The objective of this study is to analyze the positive relationship between different dimensions (knowledge, attitudes, and ability) of the Climate-Change Competence in the participants of a Massive Open Online Course called "Awareness and Training on Climate Change for Primary and Secondary Teachers". This study describes the use of this competenc...

We introduce a novel technique for the focal spot location based on Two-Photon Absorption effect, measured with a Si detector along the optical axis. A focus location was performed at 1550 nm with an error of ± 5 µ m.

The Split Step Fourier (SSF) method is used to propagate Gaussian beams in media with nonlinear properties. The method is validated by comparing the results between the analytical solution and the SSF for low powers.

The displacement of a sprint kayak can be described by a one-dimensional mathematical model, which, in its simplest case, is analogous to the free-fall problem with quadratic drag and constant propulsion. To describe realistic cases, it is necessary to introduce a propulsion capable of reproducing the characteristics of the kayak stroke, including...

Whole schools are excellent models to implement the Education for Sustainable Development (ESD) or Climate Change Competence (C3). These schools aim to introduce the principles of the ESD and the C3 by implementing programs where teaching and learning is made by doing, Among the programs for whole-schools introduced by Teachers for Future, the prog...

Analizaremos el papel de la Universidad como formador de docentes, sus herramientas educativas y su papel como motor de cambio en un tema de urgencia social, en el que no puede mantenerse al margen. El Cambio Climático es actualmente el mayor desafío para la humanidad y la Educación se va a convertir en clave para enfrentarse a este problema. Con e...

Non-Melanoma skin cancer is one of the most frequent types of cancer. Early detection is encouraged so as to ensure the best treatment, Hyperspectral imaging is a promising technique for non-invasive inspection of skin lesions, however, the optimal wavelengths for these purposes are yet to be conclusively determined. A visible-near infrared hypersp...

Hard X-ray radiation with high brightness and high fluxes is nowadays available on the fourth generation of synchrotrons and X-FELs, but the large size and complexity of these sources makes its use difficult for widespread applications. New table top X-ray sources driven by ultrashort high power lasers offer a compelling route to expand the availab...

Resumen: Este estudio se centra en analizar las creencias que tienen profesores de España y Latinoamérica sobre el cambio climático, prestando especial atención a la percepción general que tienen del fenómeno, la concienciación, las preocupaciones y al conocimiento de determinados fundamentos científicos. Para recoger la información, se utilizó un...

El Cambio Climático (CC) es la mayor amenaza para nuestra sociedad, pero, aunque la ciencia presenta evidencias claras sobre la magnitud del problema y describe con precisión las consecuencias, las personas no están actuando lo suficiente. La razón detrás de esta paradoja podría ser la no apropiada Representación Social (RS) sobre el CC en la socie...

Climate Change (CC) is the greatest threat to our society, but although science presents evidence of the magnitude of the problem and accurately describes the consequences, people are not acting enough. The reason behind this paradox could be the inappropriate Social Representation (SR) on CC in society and may explain why there are still skeptical...

Climate change is the greatest environmental, social and economic threat of our time and affects all forms of life on earth. Although important advances have been made such as the Paris agreement, social action is needed to mobilize the population. Education needs to become a fundamental tool for climate change mitigation, adaptation and resilience...

In order to increase scientific competence within the general population, it is important that teachers and educators have a realistic image of science and scientists, leaving aside superstitions and pseudoscientific claims that could be transmitted to their students. A starting point in this strategy is to make a good diagnosis of the future teach...

Laser-plasma interactions at high intensities are often accompanied by emission of a strong electromagnetic pulse (EMP) interfering with particle detectors or other electronic equipment. We present experimental evidence for significant differences in noise amplitudes in laser-proton acceleration from aluminium as compared to mylar target foils. Suc...

We report the development of a stable high-average power X-ray source generated by the interaction of ultrashort laser pulses (35 fs, 1 mJ, 1 kHz) with a solid target in air. The achieved source stability, which is essential for the applications foreseen for these laser-driven plasma accelerators, is due to the combination of precise positioning of...

We investigate the double ionization of a model Neon atom in strong middle infrared laser pulses by simulating the classical trajectories of the electron ensemble. After one electron tunnels out from the laser-dressed Coulomb barrier, it might undergo different returning trajectories depending on its initial transverse momentum, which in this wavel...

Climate Change is the most important threat to our planet. The Paris Agreement of 2015 provides a strategy to reduce its impacts through decarbonization, but this pathway requires a deep change in the society. Education has been identified as a major tool for adaptation and mitigation in many international treaties, but a general framework or strat...

Climate Change is the most important threat to our planet. The Paris Agreement of 2015 provides a strategy to reduce its impacts through decarbonization, but this pathway requires a deep change in the society. Education has been identified as a major tool for adaptation and mitigation in many international treaties, but a general framework or strat...

We investigate the longitudinal photon-momentum transfer in nonsequential double ionization of argon atoms exposed to a 2.0−μm linearly polarized strong laser field. The zero momentum of the photoelectron is precisely calibrated using the photoelectron-photoion coincidence spectrum. The sum-longitudinal momentum of two photoelectrons from the doubl...

El cambio climático (CC) es la mayor amenaza a la civilización y a todas las especies que viven en el planeta tierra. Para poder contener el impacto de este cambio es necesario acometer los objetivos de París 2015 y llevar a cabo una rápida descarbonización de la economía para 2050. El Panel Intergubernamental de Expertos sobre el Cambio Climático...

Climate Change is the most important threat to our society and all species on Earth. Large alterations in the climate are affecting every aspect of our society and in order to limit this impact we must decarbonize the economy before 2050. Although science presents solid evidence on the magnitude of the problem and outlines precisely the consequence...

Climate Change is the most important challenge that humanity faces today. The rapid increase in global temperatures during the last century due to an exponential increase of greenhouse gas concentrations is altering the climate beyond our capacity of adaptation. In order to mobilize the society towards bold, informed, coherent responses, public ins...

Climate change (CC) is the greatest environmental, economic and political threat for society. The scientists of the IPCC (Intergovernmental Panel on Climate Change) consider that an increase of 2 °;C with respect to the temperature of the pre-industrial era is the limit for dangerous and catastrophic changes in our planet Earth. For this reason, th...

The Laser Laboratory for Acceleration and Applications (L2A2) is a new facility, recently built at the University of Santiago de Compostela in Spain, to investigate laser–plasma acceleration technologies. This facility is equipped with a 50 TW laser system and a radio-protected area where different laser–plasma induced radiation sources are being i...

Climate Change is one of the most challenging problems that humanity faces today. To understand the magnitude and significance of the problem, society should use education as a way to create a fair, coherent and coordinated response. In this paper we describe the motivations, the design principles and the contents of a course that has been created...

In this paper, we present a target system to produce protons from laser plasma interactions at high repetition rates. In order to increase the number of available shots needed for the foreseen application, the target system will help to improve the reproducibility and stability of the proton source. We describe the experiments that we will carry ou...

We report the development of a fast rotating target to produce ultrashort incoherent X-ray pulses from bremsstrahlung. These short X-ray pulses are produced in the laser-plasma interaction of a 35 fs, 1 mJ pulse of a Ti:Sa laser of 1 kHz repetition rate, with a solid metallic target. In this paper, we report our developments to improve the stabilit...

We investigate tunneling ionization of a model helium atom in a strong circularly polarized short laser pulse using the classical backpropagation method and compare ten different tunneling criteria on the same footing, aiming for a consistent classical picture of the tunneling dynamics. These tunneling criteria are categorized into velocity-based,...

We report the development of a fast rotating target to produce ultrashort incoherent X-ray pulses from bremsstrahlung. These short X-ray pulses are produced in the laser-plasma interaction of a 35 fs, 1 mJ pulse of a Ti:Sa laser of 1 kHz repetition rate, with a solid metallic target. In this paper, we report our developments to improve the stabilit...

We report theoretical calculations of the delay in photoemission from CO with particular emphasis on the role of the ultrafast electronic bound dynamics. We study the delays in photoionization in the HOMO and HOMO-1 orbitals of the CO molecule by looking into the stereo Wigner time delay technique. That compares the delay in photoemission from elec...

We present a new technique that we have defined as the z-scan confocal method to determine the absolute location and size of the focal spot in a tight focused ultrashort laser pulse. The method permits to accurately position a target in the focal spot with a fast response. The technique is designed to help to automatize the location of an overdense...

A method to generate a polarization gate for multicycle laser pulses is presented. We study the performance of a pulse with time-dependent polarization to produce a single attosecond pulse after its interaction with an overdense plasma. The polarization gate is generated through the use of cross-polarized wave generation in a single BaF2 crystal co...

The interaction of ultrashort, high intensity laser pulses with thin foil targets leads to ion acceleration on the target rear surface. To make this ion source useful for applications, it is important to optimize the transfer of energy from the laser into the accelerated ions. One of the most promising ways to achieve this consists in engineering t...

p>En este artículo presentamos el proyecto Arenero Educativo que utiliza la tecnología de Realidad Aumentada para implementar un recurso para la enseñanza de las matemáticas y las ciencias naturales. Esta instalación usa una cámara infrarroja para leer la superficie tridimensional de la arena y después dibujar sobre ella curvas de nivel y cuerpos d...

In this paper, we describe the implementation of an Augmented Reality Sandbox as a platform for educative experiences. Usually, the traditional Augmented Reality experiences, where the interface is a screen of a mobile devices, here the interface is real sand. It can form real landscapes where a virtual layer of information is displayed. We constru...

The cross-polarized wave-generation (XPW) nonlinearity has become the standard solution for producing high-contrast pulses in the amplification chain of femtosecond high-power laser systems. These high-contrast pulses are essential for the study of laser–plasma interaction with solid targets, and therefore it is very important to advance our unders...

The carrier envelope phase (CEP) is a crucial parameter for a few-cycle laser pulse since it substantially determines the laser waveform. Stepping forward from infrared to extreme ultraviolet (EUV) pulses, we propose a strategy to directly characterize the CEP of an isolated attosecond pulse (IAP) by numerically simulating the tunneling ionization...

Laser wakefield acceleration permits the generation of ultra-short, high-brightness relativistic electron beams on a millimeter scale. While those features are of interest for many applications, the source remains constraint by the poor stability of the electron injection process. Here we present results on injection and acceleration of electrons i...

The development of compact laser-based synchrotron sources is a field of active research. Here we present recent results on an all-optical Compton backscattering source using laser-accelerated electrons and a plasma mirror, as introduced in [K. Ta Phuoc et al., Nature Photonics 6 (5) (2012) 308-311].Scattering of quasi-monoenergetic electrons of up...

Tunneling ionization of atoms and molecules plays a major role in strong field physics. In this paper we study the nuclear version of this phenomenon: tunneling dissociation of ${{\mathrm{H}}_{2}}^{+}$ and its isotopes in the interaction with THz pulses. We show strong evidence supporting the concept of tunneling dissociation by numerically solving...

Ionization by an attosecond pulse launches an electron wave packet in the continuum which contains rich information about the pulse, the parent system, and the ionization dynamics. This emission process is not instantaneous in the sense that the electrons take a finite time to leave the potential. This time is closely related to the Wigner time. In...

Ionization by an attosecond pulse launches an electron wave packet in the continuum which contains rich information about the pulse, the parent system, and the ionization dynamics. This emission process is not instantaneous in the sense that the electrons take a finite time to leave the potential. This time is closely related to the Wigner time. In...

The technological development of ultrashort laser pulses makes it possible to monitor and control the dynamics of the electrons in atoms and molecules. In this Chapter we first review recent experimental and theoretical progress towards tracking and understanding of electron motion in nature’s simplest molecule, the hydrogen molecular ion, on its n...

We study the energy exchange via electron correlation upon photon absorption over large distances in double photoionization of the helium dimer. Results of numerical simulations of the interaction of a planar helium dimer model with a short light pulse are found to be in good agreement with recent experimental data for the angular distribution of t...

We extend the ideas of wave-packet interferometry [Remetter et al., Nat. Phys. 2, 323 (2006)] to implement the algorithm of spectral phase interferometry for direct electric-field reconstruction (SPIDER) for characterizing the amplitude and phase of electron wave packets. Single-photon ionization by an attosecond pulse launches an electron wave pac...

We extend the ideas of wave-packet interferometry [Remetter et al., Nat. Phys. 2, 323 (2006)] to implement the algorithm of spectral phase interferometry for direct electric-field reconstruction (SPIDER) for characterizing the amplitude and phase of electron wave packets. Single-photon ionization by an attosecond pulse launches an electron wave pac...

Experiments on double ionization of rare gas dimers by weak synchrotron radiation as well as by strong infrared laser pulses have been reported recently. New pathways to double ionization, in which the electrons are emitted either from the same atom or different atoms in the dimer, have been proposed on the basis of the experimental data. We apply...

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