Search

NEXT-100 is currently being constructed at the Laboratorio Subterráneo de Canfranc in the Spanish Pyrenees and will search for neutrinoless double beta decay using a high-pressure gaseous time projection chamber (TPC) with 100 kg of xenon. Charge amplification is carried out via electroluminescence (EL) which is the process of accelerating electrons in a high electric field region causing secondary scintillation of the medium proportional to the initial charge. The NEXT-100 EL and cathode regions are made from tensioned hexagonal meshes of 1 m diameter. This paper describes the design, characterization, and installation of these parts for NEXT-100. Simulations of the electric field are performed to model the drift and amplification of ionization electrons produced in the detector under various EL region alignments and rotations. Measurements of the electrostatic breakdown voltage in air characterize performance under high voltage conditions and identify breakdown points. The electrostatic deflection of the mesh is quantified and fit to a first-principles mechanical model. Measurements were performed with both a standalone test EL region and with the NEXT-100 EL region before its installation in the detector. Finally, we describe the parts as installed in NEXT-100, following their deployment in Summer 2023.

Polytetrafluoroethylene (PTFE) is an excellent diffuse reflector widely used in light collection systems for particle physics experiments. In noble element systems, it is often coated with tetraphenyl butadiene (TPB) to allow detection of vacuum ultraviolet scintillation light. In this work this dependence is investigated for PTFE coated with TPB in air for light of wavelengths of 200 nm, 260 nm, and 450 nm. The results show that TPB-coated PTFE has a reflectance of approximately 92% for thicknesses ranging from 5 mm to 10 mm at 450 nm, with negligible variation as a function of thickness within this range. A cross-check of these results using an argon chamber supports the conclusion that the change in thickness from 5 mm to 10 mm does not affect significantly the light response at 128 nm. Our results indicate that pieces of TPB-coated PTFE thinner than the typical 10 mm can be used in particle physics detectors without compromising the light signal.

We present a tunable metal ion beam that delivers controllable ion currents in the picoamp range for testing of dry-phase ion sensors. Ion beams are formed by sequential atomic evaporation and single or multiple electron impact ionization, followed by acceleration into a sensing region. Controllability of the ionic charge state is achieved through tuning of electrode potentials that influence the retention time in the ionization region. Barium, lead, and cadmium samples have been used to test the system, with ion currents identified and quantified using a quadrupole mass analyzer. Realization of a clean Ba2+ ion beam within a bench-top system represents an important technical advance toward the development and characterization of barium tagging systems for neutrinoless double beta decay searches in xenon gas. This system also provides a testbed for investigation of novel ion sensing methodologies for environmental assay applications, with dication beams of Pb2+ and Cd2+ also demonstrated for this purpose.

Radio-frequency (RF) carpets with ultra-fine pitches are examined for ion transport in gases at atmospheric pressures and above. We develop new analytic and computational methods for modeling RF ion transport at densities where dynamics are strongly influenced by buffer gas collisions. An analytic description of levitating and sweeping forces from phased arrays is obtained, then thermodynamic and kinetic principles are used to calculate ion loss rates in the presence of collisions. This methodology is validated against detailed microscopic SIMION simulations. We then explore a parameter space of special interest for neutrinoless double beta decay experiments: transport of barium ions in xenon at pressures from 1 to 10 bar. Our computations account for molecular ion formation and pressure dependent mobility as well as finite temperature effects. We discuss the challenges associated with achieving suitable operating conditions, which lie beyond the capabilities of existing devices, using presently available or near-future manufacturing techniques.

[ES] El trabajo se centrará en el diseño de un sub-bloque perteneciente al prototipo de un chip. En concreto, se diseñará el bloque de polarización que alimentará al resto de componentes del dispositivo, justificando en cada caso las decisiones tomadas concernientes al diseño y su topología. El diseño a su vez ha de contemplar todos los requisitos necesarios como precisión, variación con temperatura.. que deben ser cumplidos para que el resto de componentes puedan funcionar correctamente y con normalidad. Se incluirá una robusta batería de test y simulaciones para comprobar y asegurar el correcto funcionamiento en cada uno de los posibles escenarios y teniendo el cuenta el efecto introducido por errores de proceso, fabricación... El proceso de diseño cubrirá las fases de Diseño: 1.5-2 meses Test: 0.5-1 meses Layout y post-procesado: 0.5-1 meses

[ES] El objetivo del trabajo consiste en la implementación de un sistema de sincronización de módulos de adquisición de datos empleando un método que permite alcanzar errores inferiores a 50 picosegundos. El sistema emplea enlaces de datos de alta velocidad con el reloj embebido, en los que se calibran las latencias de transmisión y se recuperan los relojes en los distintos módulo de adquisición de forma continua. Esto permite reducir la complejidad de los sistemas de adquisición donde la resolución temporal global es muy importante, como en las aplicaciones para PET, ya que hace posible prescindir de elementos dedicados para el reparto del reloj y otras señales sensibles a lo largo de todos los elementos del conjunto. El sistema fue implementado originalmente en [1] pero sus características hacen que sea muy dependiente de los dispositivos programables empleados. En este trabajo se propone la implementación de esta idea general sobre el sistema de adquisición de PETALO, un scanner PET basado en Xe líquido que se está desarrollando en la actualidad en colaboración con científicos del DIPC (Donosti International Physics Center) El trabajo se plantea como un desarrollo en dos fases: La primera sobre documentación bibliográfica, y estudio del algoritmo a implementar y del sistema de adquisición de datos. En la segunda se procederá a la implementación del algoritmo y el test sobre un prototipo funcional del sistema de adquisición [1] Aliaga Varea, RJ.; Monzó Ferrer, JM.; Spaggiari, M.; Ferrando Jódar, N.; Gadea Gironés,R.; Colom Palero, RJ. (2011). PET System Synchronization and Timing Resolution UsingHigh-Speed Data Links. IEEE Transactions on Nuclear Science. 58(4):1596-1605.doi:10.1109/TNS.2011.2140130.

[ES] El uso de sensores de efecto Hall para la medición de corrientes es habitual debido a las ventajas prácticas que comporta, ya que al contrario de los sensores basados en shunts de tipo resistivo, se trata de un método no invasivo que no altera las propiedades del circuito bajo medida. Las aplicaciones de este tipo de sensores se han extendido también al ámbito de la microelectrónica demostrando su validez para la implementación tanto de supervisores de consumo, como de detectores de campos magnéticos. Éste último caso ha permitido el desarrollo de brújulas y giróscopos electrónicos que se integran en multitud de dispositivos. Dado que las magnitudes que se miden en este tipo de sensores son muy reducidas el diseño de los sistemas de alimentación y amplificación frontend es crítico. El presente TFM se centra en el diseño de sistemas de polarización de alta precisión para este tipo de sensores en el entorno de los circuitos integrados (ASIC).

[EN] This article describes the event detection system of the NEXT-White detector, a 5 kg high pressure xenon TPC with electroluminescent amplification, located in the Laboratorio Subterráneo de Canfranc (LSC), Spain. The detector is based on a plane of photomultipliers (PMTs) for energy measurements and a silicon photomultiplier (SiPM) tracking plane for offline topological event filtering. The event detection system, based on the SRS-ATCA data acquisition system developed in the framework of the CERN RD51 collaboration, has been designed to detect multiple events based on online PMT signal energy measurements and a coincidence-detection algorithm. Implemented on FPGA, the system has been successfully running and evolving during NEXT-White operation. The event detection system brings some relevant and new functionalities in the field. A distributed double event processor has been implemented to detect simultaneously two different types of events thus allowing simultaneous calibration and physics runs. This special feature provides constant monitoring of the detector conditions, being especially relevant to the lifetime and geometrical map computations which are needed to correct high-energy physics events. Other features, like primary scintillation event rejection, or a double buffer associated with the type of event being searched, help reduce the unnecessary data throughput thus minimizing dead time and improving trigger efficiency.

[EN] In the world of algorithm acceleration and the implementation of deep neural networks' recall phase, OpenCL based solutions have a clear tendency to produce perfectly adapted kernels in graphic processor unit (GPU) architectures. However, they fail to obtain the same results when applied to field-programmable gate array (FPGA) based architectures. This situation, along with an enormous advance in new GPU architectures, makes it unfeasible to defend an acceleration solution based on FPGA, even in terms of energy efficiency. Our goal in this paper is to demonstrate that multikernel structures can be written based on classic systolic arrays in OpenCL, trying to extract the most advanced features of FPGAs without having to resort to traditional FPGA development using lower level hardware description languages (HDLs) such as Verilog or VHDL. This OpenCL methodology is based on the intensive use of channels (IntelFPGA extension of OpenCL) for the communication of both data and control and on the refinement of the OpenCL libraries using register transfer logic (RTL) code to improve the performance of the implementation of the base and activation functions of the neurons and, above all, to reflect the importance of adequate communication between the layers when implementing neuronal networks

[EN] Double electron capture by proton-rich nuclei is a second-order nuclear process analogous to double beta decay. Despite their similarities, the decay signature is quite di erent, potentially providing a new channel to measure the hypothesized neutrinoless mode of these decays. The Standard-Model-allowed two-neutrino double electron capture has been predicted for a number of isotopes, but only observed in 78Kr, 130Ba and, recently, 124Xe. The sensitivity to this decay establishes a benchmark for the ultimate experimental goal, namely the potential to discover also the lepton-number-violating neutrinoless version of this process. Here we report on the current sensitivity of the NEXT-White detector to 124Xe 2 ECEC and on the extrapolation to NEXT-100. Using simulated data for the 2 ECEC signal and real data from NEXT-White operated with 124Xe-depleted gas as background, we de ne an optimal event selection that maximizes the NEXT-White sensitivity. We estimate that, for NEXT-100 operated with xenon gas isotopically enriched with 1 kg of 124Xe and for a 5-year run, a sensitivity to the two-neutroni double electron capture half-life of 6x10exp22 years (at 90% con dence level) or better can be reached.

[EN] Convolutional neural networks (CNNs) are widely used state-of-the-art computer vision tools that are becoming increasingly popular in high-energy physics. In this paper, we attempt to understand the potential of CNNs for event classification in the NEXT experiment, which will search for neutrinoless double-beta decay in Xe-136. To do so, we demonstrate the usage of CNNs for the identification of electron-positron pair production events, which exhibit a topology similar to that of a neutrinoless double-beta decay event. These events were produced in the NEXT-White high-pressure xenon TPC using 2.6 MeV gamma rays from a Th-228 calibration source. We train a network on Monte Carlo-simulated events and show that, by applying on-the-fly data augmentation, the network can be made robust against differences between simulation and data. The use of CNNs offers significant improvement in signal efficiency and background rejection when compared to previous non-CNN-based analyses

Next-generation neutrinoless double beta decay experiments aim for half-life sensitivities of ∼ 1027 yr, requiring suppressing backgrounds to < 1 count/tonne/yr. For this, any extra background rejection handle, beyond excellent energy resolution and the use of extremely radiopure materials, is of utmost importance. The NEXT experiment exploits differences in the spatial ionization patterns of double beta decay and single-electron events to discriminate signal from background. While the former display two Bragg peak dense ionization regions at the opposite ends of the track, the latter typically have only one such feature. Thus, comparing the energies at the track extremes provides an additional rejection tool. The unique combination of the topology-based background discrimination and excellent energy resolution (1% FWHM at the Q-value of the decay) is the distinguishing feature of NEXT. Previous studies demonstrated a topological background rejection factor of ∼ 5 when reconstructing electron-positron pairs in the 208Tl 1.6 MeV double escape peak (with Compton events as background), recorded in the NEXT-White demonstrator at the Laboratorio Subterráneo de Canfranc, with 72% signal efficiency. This was recently improved through the use of a deep convolutional neural network to yield a background rejection factor of ∼ 10 with 65% signal efficiency. Here, we present a new reconstruction method, based on the Richardson-Lucy deconvolution algorithm, which allows reversing the blurring induced by electron diffusion and electroluminescence light production in the NEXT TPC. The new method yields highly refined 3D images of reconstructed events, and, as a result, significantly improves the topological background discrimination. When applied to real-data 1.6 MeV e−e+ pairs, it leads to a background rejection factor of 27 at 57% signal efficiency.

[ES] PETALO (Aparato TOF de Emisión de Positrones basado en Xenón Líquido) explota las características únicas del Xenón líquido como escintilador. Su rápida respuesta en el tiempo y su alto rendimiento de centelleo permiten la construcción de detectores de gran área con forma personalizable que son necesarios para los escáneres PET de cuerpo entero. El concepto de detector continuo PETALO se basa en una estructura cilíndrica con su pared exterior cubierta por un conjunto densamente lleno de SiPM sensibles a los VUV y una capa de xenón líquido que actúa como medio centelleante. Con el fin de aprovechar al máximo las capacidades de PETALO, se diseñó una arquitectura de lectura para manejar la gran cantidad de datos generados por el detector sin degradar las características de tiempo. Se han aplicado técnicas de compresión de imágenes para aliviar los requisitos de velocidad de enlace de datos, lo que hace que la lectura sea más asequible en términos de coste y complejidad. Sin embargo, el verdadero potencial del detector continuo aún no se ha explotado plenamente. Un procesamiento más profundo de la distribución de la luz adquirida por el detector podría mejorar su rendimiento. El análisis Monte Carlo del proceso de detección de rayos gamma muestra una notable cantidad de eventos que, aunque afectados por la dispersión Compton, introducen una desviación insignificante en la estimación de la posición final. En este TFM se presenta una nueva técnica de procesamiento basada en una red neuronal implementada por hardware dentro de la lectura. Este nuevo elemento proporciona un mecanismo de etiquetado de calidad que mide el error potencial de reconstrucción de posición debido a la dispersión de Compton durante la detección de eventos. Esta información está disponible en la primera fase del sistema de adquisición de datos, que permite el rechazo precoz de los peores acontecimientos, reduciendo así aún más el tráfico de datos. También se puede mejorar la calidad de la imagen

[EN] High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have measured the electroluminescence (EL) yield of Xe-He mixtures, in the range of 0 to 30% He and demonstrated the small impact on the EL yield of the addition of helium to pure xenon. For a typical reduced electric field of 2.5 kV/cm/bar in the EL region, the EL yield is lowered by similar to 2%, 3%, 6% and 10% for 10%, 15%, 20% and 30% of helium concentration, respectively. This decrease is less than what has been obtained from the most recent simulation framework in the literature. The impact of the addition of helium on EL statistical fluctuations is negligible, within the experimental uncertainties. The present results are an important benchmark for the simulation tools to be applied to future optical TPCs based on Xe-He mixtures.

[EN] Polytetrafluoroethylene (PTFE) is an excellent diffuse reflector widely used in light collection systems for particle physics experiments. However, the reflectance of PTFE is a function of its thickness. In this work, we investigate this dependence in air for light of wavelengths 260 nm and 450 nm using two complementary methods. We find that PTFE reflectance for thicknesses from 5 mm to 10 mm ranges from 92.5% to 94.5% at 450 nm, and from 90.0% to 92.0% at 260 nm We also see that the reflectance of PIFE of a given thickness can vary by as much as 2.7% within the same piece of material. Finally, we show that placing a specular reflector behind the PTFE can recover the loss of reflectance in the visible without introducing a specular component in the reflectance.

[EN] Xe-136 is used as the target medium for many experiments searching for 0 nu beta beta. Despite underground operation, cosmic muons that reach the laboratory can produce spallation neutrons causing activation of detector materials. A potential background that is difficult to veto using muon tagging comes in the form of Xe-137 created by the capture of neutrons on Xe-136. This isotope decays via beta decay with a half-life of 3.8 min and a Q(beta) of similar to 4.16 MeV. This work proposes and explores the concept of adding a small percentage of He-3 to xenon as a means to capture thermal neutrons and reduce the number of activations in the detector volume. When using this technique we find the contamination from Xe-137 activation can be reduced to negligible levels in tonne and multi-tonne scale high pressure gas xenon neutrinoless double beta decay experiments running at any depth in an underground laboratory.

[ES] El objetivo final de éste TFM consiste en realizar un diseño de test de un front end integrado para grandes arrays de SiPM. Como una primera aproximación se implementará el front end de un sólo canal en una tecnología típica (0.35um) para evaluar el diseño y localizar los puntos críticos de la cadena de señal analógica. En paralelo se evaluarán las topologías de TDC (Convertidore de tiempo a digital) así como los convertidores analógico digitales multicanal para proponer una combinación TDC+ADC que sea capaz de generar los valores de marca de tiempos y carga digitales asociados a cada evento detectado. El TFM tendrá tres fases: 1) Diseño e implementación de un preamplificador para front end integrado de SiPM en una tecnología de 0.35um. El preamplificador proporcionará dos salidas de corriente que alimentarán la rama de tiempos (optimizada para señales rápidas) y la rama de carga (optimizada para la integración de carga). El canal del front end integrado debe tener resolución de un fotoelectrón (50 fC) y un rango dinámico superior a 1000 fotoelectrones. 2) Diseño de un integrador de carga con señal de inicio de integración y ventana de integración configurable (125 ns / 250 ns / 500 ns]. El tiempo de descarga deberá ser inferior al 10% del tiempo de integración maś corto. 3) Diseño de un memoria analógica de 8 positiones para almacenar la integración de eventos previos. La memoria debería tener la estructura de una FIFO con señales de estado y protocolos de lectura y escritura., [EN] The final goal of these master thesis proposals aims at carrying out a test design of an integrated front end for large arrays of SiPM. As a first approach, a single front end channel will be implemented in a 0.35um technology node to check for the feasibility of this design and locate the key points of the analog signal chain. In a parallel thread, a survey on Time to Digital Converter (TDC) topologies as well as multichannel Analog to Digital Converters will be done in order to propose an optimal set of TDC + ADC elements which will translate front end channels outputs to timestamp and charge digital data. The Master Thesis will cover three phases: 1) Design and implementation of an input Preamplifier for the integrated SiPM front end using a 0.35um technology kit. The Preamplifier will provide two different current outputs which will feed the Time Branch (optimized for fast signals) and the Charge Branch (optimized for charge integration). The integrated front end channel must have single photoelectron (50 fC) resolution capability and a high dynamic range (over 1000 pe). 2)Design of a charge gated integrator with integration start threshold control and configurable integrating window [125 ns / 250 ns / 500 ns]. Discharge operation time should be below 10% of the shortest integrating window. 3)Design of an 8 cell analog memory to store previous integrator results. The memory behavior should follow a FIFO model with status flags and read/write protocols.

[EN] Motivated by the possibility of guiding daughter ions from double beta decay events to single-ion sensors for barium tagging, the NEXT collaboration is developing a program of R&D to test radio frequency (RF) carpets for ion transport in high pressure xenon gas. This would require carpet functionality in regimes at higher pressures than have been previously reported, implying correspondingly larger electrode voltages than in existing systems. This mode of operation appears plausible for contemporary RF-carpet geometries due to the higher predicted breakdown strength of high pressure xenon relative to low pressure helium, the working medium in most existing RF carpet devices. In this paper we present the first measurements of the high voltage dielectric strength of xenon gas at high pressure and at the relevant RF frequencies for ion transport (in the 10MHz range), as well as new DC and RF measurements of the dielectric strengths of high pressure argon and helium gases at small gap sizes. We find breakdown voltages that are compatible with stable RF carpet operation given the gas, pressure, voltage, materials and geometry of interest.

[ES] El alumno deberá de realizar un estudio bibliográfico sobre convertidores ADC y en particular sobre convertidores de aproximaciones sucesivas de tipo capacitivo. Dichos convertidores son los que presentan un mejor balance precisión-consumo de cara a su integración en un sistema multicanal. En una segunda fase el alumno propondrá una arquitectura para su implementación integrada y localizará cuales son los elementos críticos. En una tercera fase el alumno describirá el sistema completo del convertidor mediante una herramienta de modelización analógica de alto nivel (Verilog-A) y diseñará aquellos bloques indentificados previamente como críticos a nivel de transistor siguiendo un procedimiento razonado para la elección de su topología así como el dimensionamiento de los transistores. La duración estimada para la primera y segunda fases será de 1 mes (aprox.). La tercera fase debido a su mayor complejidad tendrá una duración de 3-4 meses.

[ES] Esta tesis trata sobre la implementación con ROS del sistema de control de un Vehículo Operado Remotamente (ROV), Minerva II, en el Laboratorio de Robótica Submarina Aplicada en el Departamento de Tecnología Marina de la Universidad Noruega de Ciencia y Tecnología (NTNU). El trabajo está relacionado con una estación de acoplamiento submarina que se desarrolla junto con la compañía petrolera noruega Equinor. El proyecto se centra en la implementación de controladores de los grados de libertad movimiento del ROV; deriva, avance, guiñada y arfada. El sistema operativo del robot gestiona las comunicaciones entre bloques como el simulador HIL y el ROV, dando órdenes para recibir y enviar mensajes entre ellos. Para este propósito, el proyecto se implementa en Python y se basa en las comunicaciones de un sistema de control interno desarrollado en LabVIEW., [EN] This thesis is about the implementation with ROS of the control system for the Remotely Operated Vehicle (ROV) Minerva II in the Applied Underwater Robotics Laboratory at the Department of Marine Technology of the Norwegian University of Science and Technology (NTNU). The work is related to a subsea docking station that is developed together with the norwegian oil company Equinor. The project focuses on the implementation of controllers of the ROV's degrees of freedom of movement; sway, surge, heading, and heave. The Robot Operating System manages communications between blocks such as HIL Simulator and the ROV by giving orders for receiving and sending messages between them. For this purpose, the project is implemented in Python and based on the communications of an in-house control system developed in LabVIEW.

[ES] Este proyecto final de máster se centra en actividades de desarrollo para un módulo de salidas binarias integrable en un sistema comercial de control de subestaciones eléctricas. Este proyecto ha sido realizado en la empresa Celestica Valencia para un cliente del sector de automatización y control de la red de distribución eléctrica (Smart Grid Automation), y ha seguido la siguiente estructura para su realización: ¿ Actualización del esquema del módulo: En esta nueva revisión se ha trabajado con herramientas de captura de esquemas, y de desarrollo de listas de componentes (con su correspondiente formato, para su posterior fabricación y generación de netlist, para el ruteado de la tarjeta de circuito impreso). Se han tenido en cuenta, durante esta etapa también, los requerimientos relativos a cumplimiento de la normativa aplicable, para este tipo de producto. ¿ Verificación del diseño: Definición y ejecución de pruebas necesarias para comprobación del cumplimiento de manera apropiada de los requisitos funcionales del sistema. Durante esta fase se hará código de test, se manejará instrumentación y se realizarán los informes pertinentes. ¿ Pruebas Climáticas y certificaciones EMC y seguridad eléctrica: Requeridas para la obtención del marcado CE necesario para la puesta en el mercado del producto., [EN] Abstract This final master project, it focuses on development activities for a binary output module that can be integrated into a commercial control system of electrical sub-stations. This project has been carried out at the Celestica Valencia Company for a client in the automation and control sector of the electricity distribution network (Smart Grid Automation), and has followed the following structure for its realization: ¿ Update of the module scheme: In this new revision, we have worked with tools for schema capture and component list development (with its corresponding format for its subsequent manufacture and generation of netlist for routing the printed circuit board). During this stage, the requirements regarding compliance with the applicable regulations for this type of product have also been taken into account. ¿ Design verification: Definition and execution of tests necessary to verify compliance with the functional requirements of the system. During this phase test code will be made, instrumentation will be handled and relevant reports will be made. ¿ Climatic tests and EMC certifications and electrical safety: Necessary for obtaining the CE marking necessary for placing the product on the market.

[ES] Este proyecto consiste en la implementación de un software que permite simular una comunicación basada en un documento de intercambio de señales (ICD). La aplicación software permitirá escoger un equipo cualquiera a simular actuando de: 1) Servidor, empleando para este proyecto la Unidad de Control del Proveedor para comunicarse con el equipo cliente. 2) Cliente, para comunicarse con el servidor (Unidad de Control real que proporcionará el proveedor). De esta manera se consigue que los usuarios que dispongan únicamente de un equipo real, puedan simular el equipo del que carecen con el fin de comprobar que el intercambio de los valores de las señales con el otro equipo, tanto enviadas como recibidas, se está realizando correctamente. Gracias a este software se ofrece la posibilidad de realizar una prueba de comunicación entre dos equipos sin necesidad de estar en un entorno real., [EN] This project consists of the implementation of a software that allows simulating a communication based on a signal exchange document (ICD). The software application will allow you to choose any equipment to simulate acting from: 1) Server, using for this project the Provider Control Unit to communicate with the client equipment. 2) Client, to communicate with the server (real Control Unit to be provided by the provider). By this way, users with only one real equipment can simulate the equipment they lack, in order to verify that the exchange of signal values, sent and received, between equipments it is being done properly. Thanks to this software, it is possible to carry out a communication test between two computers without having to be in a real environment.

[ES] El objetivo final de éste TFM consiste en realizar un diseño de test de un front end integrado para grandes arrays de SiPM. Como una primera aproximación se implementará el front end de un sólo canal en una tecnología típica (0.35um) para evaluar el diseño y localizar los puntos críticos de la cadena de señal analógica. En paralelo se evaluarán las topologías de TDC (Convertidore de tiempo a digital) así como los convertidores analógico digitales multicanal para proponer una combinación TDC+ADC que sea capaz de generar los valores de marca de tiempos y carga digitales asociados a cada evento detectado. El TFM tendrá dos fases: 1) Revisión de las arquitecturas TDC y propuesta de una estructura multicanal. El TDC proporcionará una marca de tiempos digital para canal disparado con una resoluciónd e 15 ps y una ventana gruesa temporal de 1s. Las señales de entrada al TDC multicanal serán las salidas "Fast" de los preamplificadores de la etapa de entrada. Será necesaria la implementación de un comparador de alta velocidad para mejorar el comportamiento de los TDC 2) Revisión de arquitecturas ADC multicanal de baja complejidad y propuesta de una estructura ADC para conversión de carga. El QDC debe proporcionar una resolución efectiva de 9 bits para cada canal disparado. El tiempo de conversión no debe exceder de 1 us, tomando en cuenta las limitaciones de la tecnología de 0.35u, [EN] The final goal of these master thesis proposals aims at carrying out a test design of an integrated front end for large arrays of SiPM. As a first approach, a single front end channel will be implemented in a 0.35um technology node to check for the feasibility of this design and locate the key points of the analog signal chain. In a parallel thread, a survey on Time to Digital Converter (TDC) topologies as well as multichannel Analog to Digital Converters will be done in order to propose an optimal set of TDC + ADC elements which will translate front end channels outputs to timestamp and charge digital data. The Master Thesis will cover two phases: 1) Review of Time to Digital Converters architectures and proposal of a multichannel input structure. The TDC must provide a digital timestamp for each triggering channel with a 15 ps resolution and a coarse timing window of 1 s. The input signals to the multichannel TDC will be that of the Fast Branches of the preamplifiers (a fast comparator will be required to enhance TDC behavior). 2) Review of medium precision lightweight multichannel ADC converters and proposal of an ADC structure for Charge Branch conversion. The QDC must provide a 9 effective bits output for each triggering channel. The conversion time must not exceed 1 us taking into account frequency limitations in the 0.35 technology kit being used in this test design.

[ES] Para resolver el trade-off entre respuesta transitoria vs Iq diversas técnicas se han presentado en el pasado para tratar de mantener la estabilidad de los LDO para diferentes corrientes de carga. Estas técnicas pueden ser clasificadas a groso modo en 3 categorias: bias adaptativo, pole-zero tracking y una combinación de ambas. Estas técnicas presentan una gran desventaja y es que tienen una respuesta bastante lenta empeorando el slew-rate del LDO. Para resolver este problema se estudiará otro método conocido como bias dynamico. La técnica de bias dinámico trata de dar un impulso de corriente al bias del LDO para compensar cambios rápidos en el voltaje de salida. El objetivo final de este trabajo es el de lograr realizar un diseño de LDO adaptativo adecuado para ser usado en aplicaciones de SoC. Gracias a su eficiencia incluso para muy bajas corrientes de carga y su habilidad para mantenerse estable para un amplio rango de corrientes

[EN] Natural radioactivity represents one of the main backgrounds in the search for neutrinoless double beta decay. Within the NEXT physics program, the radioactivity- induced backgrounds are measured with the NEXT-White detector. Data from 37.9 days of low-background operations at the Laboratorio Subterraneo de Canfranc with xenon depleted in Xe-136 are analyzed to derive a total background rate of (0.84 +/- 0.02) mHz above 1000 keV. The comparison of data samples with and without the use of the radon abatement system demonstrates that the contribution of airborne-Rn is negligible. A radiogenic background model is built upon the extensive radiopurity screening campaign conducted by the NEXT collaboration. A spectral fit to this model yields the specific contributions of Co-60, K-40, Bi-214 and Tl-208 to the total background rate, as well as their location in the detector volumes. The results are used to evaluate the impact of the radiogenic backgrounds in the double beta decay analyses, after the application of topological cuts that reduce the total rate to (0.25 +/- 0.01) mHz. Based on the best-fit background model, the NEXT-White median sensitivity to the two-neutrino double beta decay is found to be 3.5 sigma after 1 year of data taking. The background measurement in a Q(beta beta)+/- 100 keV energy window validates the best-fit background model also for the neutrinoless double beta decay search with NEXT-100. Only one event is found, while the model expectation is (0.75 +/- 0.12) events.

[EN] The NEXT experiment aims at searching for the hypothetical neutrinoless double-beta decay from the 136Xe isotope using a high-purity xenon TPC. Efficient discrimination of the events through pattern recognition of the topology of primary ionisation tracks is a major requirement for the experiment. However, it is limited by the diffusion of electrons. It is known that the addition of a small fraction of a molecular gas to xenon reduces electron diffusion. On the other hand, the electroluminescence (EL) yield drops and the achievable energy resolution may be compromised. We have studied the effect of adding several molecular gases to xenon (CO2, CH4 and CF4) on the EL yield and energy resolution obtained in a small prototype of driftless gas proportional scintillation counter. We have compared our results on the scintillation characteristics (EL yield and energy resolution) with a microscopic simulation, obtaining the diffusion coefficients in those conditions as well. Accordingly, electron diffusion may be reduced from about 10 mm/ sqrt(¿) for pure xenon down to 2.5 mm/sqrt(m) using additive concentrations of about 0.05%, 0.2% and 0.02% for CO2, CH4 and CF4, respectively. Our results show that CF4 admixtures present the highest EL yield in those conditions, but very poor energy resolution as a result of huge fluctuations observed in the EL formation. CH4 presents the best energy resolution despite the EL yield being the lowest. The results obtained with xenon admixtures are extrapolated to the operational conditions of the NEXT-100 TPC. CO2 and CH4 show potential as molecular additives in a large xenon TPC. While CO2 has some operational constraints, making it difficult to be used in a large TPC, CH4 shows the best performance and stability as molecular additive to be used in the NEXT-100 TPC, with an extrapolated energy resolution of 0.4% at 2.45 MeV for concentrations below 0.4%, which is only slightly worse than the one obtained for pure xenon. We demonstrate

[EN] In experiments searching for neutrinoless double-beta decay, the possibility of identifying the two emitted electrons is a powerful tool in rejecting background events and therefore improving the overall sensitivity of the experiment. In this paper we present the first measurement of the efficiency of a cut based on the different event signatures of double and single electron tracks, using the data of the NEXT-White detector, the first detector of the NEXT experiment operating underground. Using a 228Th calibration source to produce signal-like and background-like events with energies near 1.6 MeV, a signal efficiency of 71.6 ± 1.5 stat ± 0.3 sys% for a background acceptance of 20.6 ± 0.4 stat ± 0.3 sys% is found, in good agreement with Monte Carlo simulations. An extrapolation to the energy region of the neutrinoless double beta decay by means of Monte Carlo simulations is also carried out, and the results obtained show an improvement in background rejection over those obtained at lower energies.

[ES] El alumno realizará el diseño de un convertidor analógico digital de tipo Wilkinson e implementará sus distintas partes empleando la tecnología AMSC35 y las herramientas de Cadence IC. Se realizarán bancos de prueba de cada uno de los elementos por separado, así como del diseño final con el objetivo de evaluar sus prestaciones. La parte de control digital del ADC se modelizará mediante Verilog y no será obligatoria su implementación. Se plantea como objetivo final orientativo alcanzar una resolución mejor de 8 bits con un tiempo de conversión inferior a 5 microsegundos. Se valorará que el área ocupada sea reducida, así como su consumo con vistas a la integración de un gran número de canales., [EN] The student will design a Wilkinson ADC and will implement it using AMSC35 technology kit and Cadence IC tools. Testbenches must be developed for every part of the design as well as for the whole system in order to evaluate its performance. ADC digital control system will be modelized using Verilog and its final implementation will not be compulsory. Final design should meet the following specifications: Minimum 8 bits resolution and a conversion time below 5 microseconds. Area and power consumption should be kept to a minimum in order to allow a dense integration of this component into a channel array.

[ES] El TFG consiste en proponer un diseño para un bloque compresor de imágenes basado un esquema de Transformada Wavelet + Cuantificador. El objetivo se centra en intentar conseguir ratios de compresión inferiores o cercanos al 50% con la mayor velocidad posible de procesado. Para ello el alumno deberá de evaluar distintas bases de funciones Wavelet y escoger las que mejor se comporten para la aplicación específica, desde el punto de vista de unos parámetros concretos que son fundamentales en la determinación de la posición tridimensional del evento de absorción del fotón gamma en el detector. Una vez seleccionada la base y establecida la precisión de la cuantificación aplicada a cada salida de la transformada, se propondrá una estructura de filtro hardware en punto fijo para realizar la implementación del mismo. Dicha implementación será verificada y optimizada con vistas a conseguir la mayor frecuencia de operación y menor latencia posibles.

[ES] En el desarrollo del proyecto se buscará una correcta realización e implementación de un módulo digital de compresión de datos. Dicho módulo incluirá un algoritmo de compresión considerado óptimo y tendrá como finalidad ser implementado para reducir el flujo de datos generados en la lectura de un experimento llevado a cabo con PMTs y su distribución en tiempo real con un enlace de GbE. Las partes distinguibles dentro del proyecto serán: -Decisión del algoritmo de compresión a implementar. -Esquema de compresión. -Descripción Verilog del diseño en ISE. -Comprobación de la implementación y correcciones -Optimización, [EN] In the development of the project a correct realization and implementation of a digital module of data compression will looked for. This module will include a compression algorithm considered optimal and its purpose will be to be implemented to reduce the flow of data generated in the reading of an experiment carried out with PMTs and its distribution in real time with a GbE link. The distinguishable parts within the project will be: -Decision of the compression algorithm to be implemented. -Compression scheme. -Verilog description of the design in ISE. -Verification of the implementation and corrections. -Optimization

[EN] This paper describes the electronics of NEXT-White (NEW) detector PMT plane, a high pressure xenon TPC with electroluminescent amplification (HPXe-EL) currently operating at the Laboratorio Subterraneo de Canfranc (LSC) in Huesca, Spain. In NEXT-White the energy of the event is measured by a plane of photomultipliers (PMTs) located behind a transparent cathode. The PMTs are Hamamatsu R11410-10 chosen due to their low radioactivity. The electronics have been designed and implemented to fulfill strict requirements: an overall energy resolution below 1% and a radiopurity budget of 20 mBq unit(-1) in the chain of Bi-214. All the components and materials have been carefully screened to assure a low radioactivity level and at the same time meet the required front-end electronics specifications. In order to reduce low frequency noise effects and enhance detector safety a grounded cathode connection has been used for the PMTs. This implies an AC-coupled readout and baseline variations in the PMT signals. A detailed description of the electronics and a novel approach based on a digital baseline restoration to obtain a linear response and handle AC coupling effects is presented. The final PMT channel design has been characterized with linearity better than 0.4% and noise below 0.4mV.

[ES] Metodología de verificación mediante el sistema de clases UVM de un sub bloque funcional basado en una memoria OTP Synopsis DesignWare NVM. El bloque incluye el controlador para la memoria, sistemas de detección y corrección de errores (ECC y CRC) y una máquina de estados que descarga automáticamente el contenido de la memoria. Tanto el bloque como el test bench que lo acompaña han sido diseñados con la intención de ser altamente reutilizables y agnósticos al proyecto en el que sean instanciados, para complementar la flexibilidad que otorgan todas las opciones de configuración de la IP de la OTP.

El trabajo de fin de master tiene como objetivo integrar un sistema de compresión de datos sin pérdidas en la electrónica de adquisición del proyecto PETALO. La finalidad de este sistema es reducir el velocidad de transmisión de información necesaria en los enlaces de comunicaciones y de esa forma poder moderar los recursos necesarios para desarrollar el sistema completo. Las técnicas de compresión propuestas deberán contemplar un mínimo de latencia y la posibilidad de implementarse en un entorno de FPGA., This master thesis aims at integrating a lossless data compression system into the data acquisition architecture of the PETALO project. The goal of this system is to reduce the required bitrate in the communications links, thus simplifying the amount of resources needed in the full system implementation. The proposed compression techniques will focus in a minimum latency and a feasible FPGA based implementation.

This paper describes the electronics of NEXT-White (NEW) detector PMT plane, a high pressure xenon TPC with electroluminescent amplification (HPXe-EL) currently operating at the Laboratorio Subterráneo de Canfranc (LSC) in Huesca, Spain. In NEXT-White the energy of the event is measured by a plane of photomultipliers (PMTs) located behind a transparent cathode. The PMTs are Hamamatsu R11410-10 chosen due to their low radioactivity. The electronics have been designed and implemented to fulfill strict requirements: an overall energy resolution below 1% and a radiopurity budget of 20 mBq unit in the chain of Bi. All the components and materials have been carefully screened to assure a low radioactivity level and at the same time meet the required front-end electronics specifications. In order to reduce low frequency noise effects and enhance detector safety a grounded cathode connection has been used for the PMTs. This implies an AC-coupled readout and baseline variations in the PMT signals. A detailed description of the electronics and a novel approach based on a digital baseline restoration to obtain a linear response and handle AC coupling effects is presented. The final PMT channel design has been characterized with linearity better than 0.4% and noise below 0.4mV.

[EN] We introduce a simulation framework for the transport of high and low energy electrons in xenon-based optical time projection chambers (OTPCs). The simulation relies on elementary cross sections (electron-atom and electron-molecule) and incorporates, in order to compute the gas scintillation, the reaction/quenching rates (atom-atom and atom-molecule) of the first 41 excited states of xenon and the relevant associated excimers, together with their radiative cascade. The results compare positively with observations made in pure xenon and its mixtures with CO2 and CF4 in a range of pressures from 0.1 to 10 bar. This work sheds some light on the elementary processes responsible for the primary and secondary xenon-scintillation mechanisms in the presence of additives, that are of interest to the OTPC technology.

[EN] Conceived to host 5 kg of xenón at a pressure of 15 bar in the ¿ducial volume,the NEXTWhite (NEW)apparatus is currently the largest high pressure xenon gas TPC using electroluminescent ampli¿cation in the world. It is also a 1:2 scale model of the NEXT-100 detector scheduled to start searching for ßß0¿ decays in 136Xe in 2019. Both detectors measure the energy of the event using a plane of photomultipliers located behind a transparent cathode. They can also reconstruct the trajectories of charged tracks in the dense gas of the TPC with the help of a plane of silicon photomultipliers located behind the anode. A sophisticated gas system, common to both detectors, allows the high gas purity needed to guarantee a long electron lifetime. NEXT-White has been operating since October 2017 at the Canfranc Underground Laboratory (LSC), in Spain. This paper describes the detector and associated infrastructures.

[EN] Gaseous time projection chambers (TPC) are a very attractive detector technology for particle tracking. Characterization of both drift velocity and di¿usion is of great importance to correctly assess their tracking capabilities. NEXT-White is a High Pressure Xenon gas TPC with electroluminescent ampli¿cation, a 1:2 scale model of the future NEXT-100detector, which will be dedicated to neutrinoless double beta decay searches. NEXT-White has been operating at Canfranc Underground Laboratory (LSC) since December2016. The drift parameters have been measured using 83mKr for a range of reduced drift ¿elds at two di¿erent pressure regimes, namely 7.2 bar and 9.1 bar. Theresults have been compared with Magboltz simulations. Agreement at the 5% level or better has been found for drift velocity, longitudinal di¿usion and transverse di¿usion.

[EN] A new method to tag the barium daughter in the double-beta decay of Xe-136 is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba++) resolution at a transparent scanning surface is demonstrated. A single-step photobleach confirms the single ion interpretation. Individual ions are localized with superresolution (similar to 2 nm), and detected with a statistical significance of 12.9 sigma over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double-beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.

[EN] Neurofeedback is a self-regulation technique that can be applied to learn to voluntarily control cerebral activity in specific brain regions. In this work, a Transcranial Doppler-based configurable neurofeedback system is proposed and described. The hardware configuration is based on the Red Pitaya board, which gives great flexibility and processing power to the system. The parameter to be trained can be selected between several temporal, spectral, or complexity features from the cerebral blood flow velocity signal in different vessels. As previous studies have found alterations in these parameters in chronic pain patients, the system could be applied to help them to voluntarily control these parameters. Two protocols based on different temporal lengths of the training periods have been proposed and tested with six healthy subjects that were randomly assigned to one of the protocols at the beginning of the procedure. For the purposes of the testing, the trained parameter was the mean cerebral blood flow velocity in the aggregated data from the two anterior cerebral arteries. Results show that, using the proposed neurofeedback system, the two groups of healthy volunteers can learn to self-regulate a parameter from their brain activity in a reduced number of training sessions.

[EN] The trend in meat consumption has changed drastically in the last years, mainly due to the relationship of red and processed meats with cancer and cardiovascular diseases, which has caused a substantial growth in poultry meat consumption, 8% in 2016. Therefore, poultry production has suffered an intensification that has led to an increase in the incidence of internal malformations in chickens and turkeys for fattening, especially in the pectoral muscles, as Deep Pectoral Myopathy (DPM). Currently, industry is not able to detect DPM breasts when sold as whole carcasses. In this context, the use of dielectric spectroscopy, complemented by a deep study of the chemical, biochemical and microstructural transformations of the muscle and the effect that these changes have on the electrical dispersions in radiofrequency range, may become feasible for online DPM detection. For this paper, non-damaged and affected by DPM chicken breasts (pectoralis major and pectoralis minor) was analysed. Permittivity in radiofrequency and microwave ranges were measured in the different tissues: pectoralis minor, major and skin in order to characterize them. Moreover, proteins content, ion content and pH were measured. With this data, a sensor for measuring the permittivity of chicken whole carcass with skin was developed; it consists of two pairs of two flat plates sensor connected to an impedance Agilent analyzer 4294A and can measure the permittivity from 40 Hz to 1 MHz. The results demonstrated the feasibility of the permittivity in radiofrequency range as an potential identification technique of chicken breasts affected by DPM.

[EN] In the optimization of deep neural networks (DNNs) via evolutionary algorithms (EAs) and the implementation of the training necessary for the creation of the objective function, there is often a trade-off between efficiency and flexibility. Pure software solutions implemented on general-purpose processors tend to be slow because they do not take advantage of the inherent parallelism of these devices, whereas hardware realizations based on heterogeneous platforms (combining central processing units (CPUs), graphics processing units (GPUs) and/or field-programmable gate arrays (FPGAs)) are designed based on different solutions using methodologies supported by different languages and using very different implementation criteria. This paper first presents a study that demonstrates the need for a heterogeneous (CPU-GPU-FPGA) platform to accelerate the optimization of artificial neural networks (ANNs) using genetic algorithms. Second, the paper presents implementations of the calculations related to the individuals evaluated in such an algorithm on different (CPU- and FPGA-based) platforms, but with the same source files written in OpenCL. The implementation of individuals on remote, low-cost FPGA systems on a chip (SoCs) is found to enable the achievement of good efficiency in terms of performance per watt.