ATLAS - Collaboration in the ATLAS experiment at CERNExperiências LHC e Fenomenologia
ATLAS is one of the four big experiments at CERN that exploits the full potential of discovery provided by the large hadron collider - LHC. The LIP Portuguese group signed the Letter of Intent of ATLAS and had a significant role in the design, construction, start-up of operations, trigger and data acquisition systems. The main contributions were to the hadronic calorimeter TileCal, to the forward detectors, and to the software development for jet trigger signatures. The group is contributing to detector performance studies and physics data analyses since the very first data provided by the LHC. In parallel, the group is strongly involved in the ATLAS upgrade efforts in view of operating during the High-Luminosity LHC phase, developing work mostly in TileCal and Trigger.
The ATLAS Portuguese group contributed to the discovery of the Higgs boson and is currently studying its properties. The group is a reference in the studies of the top quark and exploits this expertise in the search for physics beyond the standard model. It is also leader in exotics states studies. Last but not the least, the group is involved in the Heavy Ion program of the LHC, contributing to the study of the quark-gluon plasma (QGP), the state of matter that has occurred just after the Big Bang.
CMS - Collaboration in the CMS experiment at CERNExperiências LHC e Fenomenologia
The research at the LHC is central to the quest for the fundamental physics laws of nature. LIP is member of the Compact Muon Solenoid (CMS) Collaboration at the Large Hadron Collider (LHC) since its creation in 1992. LIP had a leading role in the design and construction of important components of the CMS detector, namely the data acquisition system of the ECAL sub-detector, used for the measurement of electrons and photons, and the CMS trigger system that performs the online selection of the interesting collisions. After the LHC start-up in 2010 LIP made major contributions to the CMS physics program, in particular: the discovery of a Higgs boson; the measurement of the top quark properties; the first observation of rare B meson decays; the measurement of the psi and upsilon polarizations; and the searches for a charged Higgs and a for a supersymmetric partner of the top quark. A LIP group member has served as Deputy Spokesperson of the Collaboration in 2012-13.
After a two-year shutdown the LHC resumed operation in 2015 with the energy increased to 13 TeV. In preparation for the new beam conditions, the LIP group contributed to the upgrade of the experiment by building and installing a large set of high-speed optical links (oSLB-oRM) that interface the ECAL electronics to the trigger system.The LIP group led the development of the new CTPPS forward proton spectrometer, which took physics data integrated in CMS in 2016-17-18. CTPPS has proven for the first time the feasibility of operating a near-beam proton spectrometer at high luminosity on a regular basis. Since 2018 the project has been organized as a fully integrated sub detector of CMS, named PPS, with one LIP member serving as deputy Project Manager. The group is actively involved and contributing to the physics analysis of the new data in the areas of top physics, Higgs physics, B physics, Supersymmetry, and PPS physics.
The group is participating in the CMS Phase 2 Upgrade for the High-Luminosity LHC. R&D in collaboration with Portuguese industry is being pursued in view of the development of microelectronics blocks for the front end readout systems of the MIPTiming Detector (MTD), the Electromagnetic Calorimeter (ECAL), and the High Granularity Calorimeter (HGCAL). The LIP group is taking a leading responsibility in the development of the readout system of the MTD barrel. The development, prototyping and integration with detector modules is being performed in the TagusLIP laboratory.
Pheno - PhenomenologyExperiências LHC e Fenomenologia
LIP’s Phenomenology group conducts research bridging theory and experiment in particle and astroparticle physics. Its research, while independent, is centred around areas in which LIP has active experimental activities and aims to identify areas in which LIP’s broader programme may evolve in the future. Its purpose is to strengthen the impact of the overall LIP programme through the provision of excellent directed phenomenological research. The members of the group have an excellent publication record and high international visibility.
The group was created in January 2018 following an extensive discussion process within LIP. Its resulted from the aggregation of two previously existing LIP groups: LHC Phenomenology and Heavy Ion Phenomenology. In this first phase, the group is focused on consolidating its research lines and identity. At the same time, its scientific output and appeal to students have been strengthened. This combination places the group on a positive path of continued development and relevance both within and outside LIP.
Partons and QCD - Participation in the COMPASS and AMBER experiments at CERNEstrutura da matéria
COMPASS is a fixed target experiment at CERN using high energy muon and hadron beams to study the nucleon spin structure and hadron spectroscopy. During its first phase COMPASS achieved the world most direct and precise measurement of the gluon contribution to the nucleon spin. A second research programme started in 2012 and is now close to completion, devoted to the 3-dimensional characterization of the nucleon structure. An addendum to the COMPASS-II proposal was approved in 2018 by the CERN Research Board, for additional deep inelastic scattering (DIS) measurements using a transversely polarised deuteron target in 2021.
The LIP group joined COMPASS in 2003 and since then it has been involved in the main analyses of the Collaboration. The group has the sole responsibility for the Detector Control System (DCS), an area where it has a recognized unique expertise. The LIP group is also strongly involved in the preparation of a new CERN experiment, using the same beam line and parts of the COMPASS spectrometer, to address important quantum chromodynamics (QCD) topics.
HADES - Collaboration in the HADES experiment at GSIEstrutura da matéria
The LIP-HADES group was originally created for the design and construction of a Time of Flight (TOF) detector based on Resistive Plate Chambers (RPCs), the RPC-TOF-Wall (RPC-TOF-W), for the HADES spectrometer at GSI, Darmstad, Germany. More recently, new members joined the group and took responsibilities on data analysis. The LIP group assumed new commitments for the construction of a new TOF detector for the HADES forward region, the RPC-TOF-FD, and is collaborating with the Multi Drift Chamber group.
The accelerator infrastructure at GSI had a long stop for the upgrade to the new FAIR facility (Facility for Antiprotons and Ion Research), at which the SIS100 synchrotron will provide higher beam energies and intensities, and has recently resumed operations. The HADES spectrometer has been upgraded with a new electromagnetic calorimeter (ECAL) and a new RICH detector. HADES has the mission to provide high-quality dilepton data at baryon densities and temperatures not accessible by other detectors, neither in the past nor in the foreseeable future.
NUC-RIA - Experimental Nuclear AstrophysicsEstrutura da matéria
Nuclear reactions are a key instrument to understand how protons and neutrons interact inside nuclear matter. By studying these reactions at different energies we can uncover details of the structure of exotic nuclear systems as well as reproduce the processes that take place in star explosions and lead to the production of the elements in our universe. The group NUC-RIA (NUClear Reactions, Instrumentation, and Astrophysics) focuses on the study of these processes working within international collaborations in European facilities devoted to the production and understanding of the properties of exotic nuclei.
The FAIR (Facility for Antiprotons and Ion Research) facility in Darmstadt, Germany, will be in the next years the world-wide leading facility in the production of exotic nuclei. By accelerating them at energies close to the speed of light, these nuclei can be studied in the R3B (Reactions with Relativistic Radioactive Beams) experiment. The NUC-RIA group has performed analysis of reaction data on halo nuclei at relativistic energies, as well as contributed to the development phases of the CALIFA electromagnetic calorimeter.
The high temperatures that can be reached in star explosions translate into very low energy reactions, involving most of the time radioactive nuclei. The study of these processes is as well a topic on which the group works, participating in experiments at the HIE-ISOLDE facility at CERN.
The development of instrumentation associated to the detection of ionizing radiation and the production of thin films for nuclear reaction processes (via thermal evaporation) are also aspects that the group works on.
NPStrong - Nuclear Physics and Strong Interaction GroupEstrutura da matéria
NPstrong, Nuclear Physics and Strong Interaction Group, is a well established group that recently joined LIP. It comprises scientists with common research interests in Nuclear and Hadron Physics who maintain a close collaboration. Currently, the common denominator of the group research activities is theoretical hadron physics.
We use nonperturbative functional methods (in contrast to a lattice discretization) to find solutions of Quantum Chromodynamics (QCD) for bound systems of quarks and gluons. These methods are complementary of lattice QCD simulations (LQCD) and provide ab-initio solutions for QCD’s correlation functions which subsequently enter in the calculation of hadron observables, where the soft and hard scales are intertwined by nonperturbative integral equations.
Applications include hot topics such as the nature of the recently discovered tetra- and pentaquark states, which are not yet understood within the framework of the traditional constituent quark model. We are also interested in determining the production mechanisms and properties of other exotic hadrons (such as quark-gluon hybrids and glueballs), as well as the spectra and internal structure of “ordinary” mesons and baryons, how they decay and couple to photons.
Big motivating questions of this activity are the origin of confinement of quarks in hadrons and nuclei, the origin of mass, and the properties of matter in extreme conditions such as heavy-ion collisions and neutron stars.
AMS - Collaboration in AMS - Alpha Magnetic SpectrometerRaios cósmicos
LIP is part of the international collaboration that designed and operates the Alpha Magnetic Spectrometer (AMS). The project had two distinct phases: a prototype was built and flown aboard the space shuttle in 1998; and the final detector was installed in the international space station (ISS) in May 2011. AMS is collecting an impressive set of data, at a continuous rate of around 45 million events per day, and has now over 130 billion events recorded. Data taking is expected to continue at least until 2024.
The LIP group took a leading role in the design, desenvolvimento, simulation and reconstruction algorithms of the AMS RICH sub-detector, aiming at measuring particle’s velocity very precisely. Today, the group keeps the responsibility for the development, implementation and maintenance of a set of algorithms for reconstructing the electric charge and velocity of particles in the RICH. The group is also involved in data analysis, with emphasis on the relations between particle flux variability and solar activity, having already published several papers not only on the correlation between the sun and the cosmic-ray flux but also on the intrinsic propagation mechanisms present in solar modulation.
Auger - Collaboration in the Pierre Auger ObservatoryRaios cósmicos
The Pierre Auger Observatory is the largest Cosmic Ray detector in the world. It has brought new fundamental insights about the origin and nature of highest-energy cosmic rays. One of the most exciting results is the experimental proof that at the highest energies the cosmic-ray flux is strongly suppressed. However, the mechanism responsible for the suppression is still a subject of debate: are we observing the result of the GZK mechanism, by which the energy of cosmic rays is degraded by their interaction with cosmic microwave background photons in their voyage to Earth, or the exhaustion of cosmic sources? Concerning composition, extensive air shower parameters seem to favour heavy composition, whereas the existence of anisotropies favours a light primary. However, the interactions of ultra high energy cosmic rays with Earth’s atmosphere are still poorly understood, and current measurements of the produced air showers aren’t able to shed light in a myriad of aspects of these interactions.
The Pierre Auger Collaboration is performing an upgrade of the full array and expects to take data at least until 2025. Scintillators are being installed on top of every water Cherenkov detector, the the electronics is being upgrades to a faster one. The aim is to achieve a better knowledge of the different components of air showers. A great effort is being put in the development of next-generation data analyses and hadronic interaction models to attain a good description of showers. The muonic component of the shower plays a particularly important role, as it can probe directly the early stages of the shower development. However, muons are only indirectly accessible even with the upgraded detector, with refined analysis required to separate them from the dominant electromagnetic signals.
A small part of the Auger array will be equipped with additional detectors that will allow for calibration and detailed response studies of the full array. In the last years the LIP team has been deeply involved in the development of the MARTA project, a joint Portugal-Brazil effort to measure directly the muon content at the shower using resistive plate chamber detectors (RPCs) installed beneath the water Cherenkov detectors. Low gas flux RPCs, able to work on a harsh outdoor environment with very little maintenance, were developed at LIP in Coimbra and built in cooperation with São Carlos, Brazil. The LIP team has also acquired a deep knowledge in shower physics and has developed innovative analyses methods and tools that will allow us to give important contributions in the analysis of the new Auger data.
LATTES - R&D for a Gamma Observatory in the Southern HemisphereRaios cósmicos
Present and planned large field-of-view (FoV) gamma-ray observatories are installed in the Northern Hemisphere, missing, in particular, the galactic center, and have energy thresholds above 0.5 TeV. The goal of the LATTES group is to participate in the design, prototyping and construction of a a ground array able to monitor the Southern gamma-ray sky above 100 GeV, bringing to ground the wide field-of-view and large duty cycle observations characteristic of satellites, with comparable sensitivity and a cost one order of magnitude lower. Such an instrument will be a powerful time-variance explorer filling an empty space in the global multi-messenger network of gravitational waves, electromagnetic telescopes in different wavelengths, and neutrino observatories. It will be able to issue pointing alerts to the large next-generation imaging atmospheric Cherenkov telescope array, CTA, being largely complementary to such observatories. It will collect abundant and highly relevant data and play a fundamental role in the search for emissions from extended regions, as the Fermi bubbles or dark matter annihilation regions.
A proof-of-concept design based on a compact air shower array of hybrid detector units composed by small water Cherenkov detectors (WCD) and resistive plate chambers (RPC) was developed in 2016-17 and published at the beginning of 2018. A proposal submitted to FCT was approved in May 2018 and provides support to the project activities for three years. We are currently working in a new layout concept, with a central core of WCDs equipped with RPC muon hodoscopes surrounded by a large number of WCDs. This layout will allow to cover a considerably larger area, thus increasing the sensitivity of the observatory.
Recently, several groups in the world that are developing similar projects started exchanging ideas and expertise, and for the first time general meetings on a future wide FoV gamma-ray detector for the southern hemisphere were organised. In a meeting held in Lisbon in May 2019 the decision was taken to create an international collaboration for R&D on such an observatory. The new collaboration joins different groups and communities that were already involved in R&D in this field, coming both from currently running experiments and from new R&D projects. The collaboration agreement is expected to be signed by July 1st by a minimum of four countries.
Dark Matter - Participation in dark matter experiments: LUX and LZNeutrinos e matéria escura
The LIP Dark Matter group joined the LUX experiment in 2010 and it is a founding member of the LUX-ZEPLIN (LZ) international collaboration. These two experiments search for dark matter in the form of Weakly Interacting Massive Particles (WIMPs), aiming at their direct detection with two-phase xenon Time Projection Chambers (TPCs).
LUX (Large Underground Xenon) is a retired experiment based on a 250 kg xenon TPC that has published three previously world leading limits on the spin-independent cross section for WIMP-nucleon scattering in the 5-1000 GeV mass range. The analysis of the science and calibration data accumulated by LUX have continued even after its decommission in 2017, resulting in over 20 papers already published or in preparation. These papers cover a large variety of topics including the search of axions, sub-GeV dark matter particles and Xe isotopes rare decays, as well as innovative calibration techniques, several aspects of the physics of xenon as detector medium and the detector performance.
LUX-ZEPLIN (LZ) is a second-generation dark matter direct detection experiment that will be deployed at the 4850-feet level of the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. The LZ detector uses 7 tonnes active mass of purified xenon in a dual phase TPC to search for potential signals from WIMPs. With 5.6 tonnes fiducial mass and a 1000 live-days long dark matter search, the projected spin-independent cross section sensitivity is 1.6 x 1048 cm2 for a 40 GeV WIMP mass, about 50 times better than the current best limit. LZ parts have started to arrive at SURF in 2018 and the detector and ancillary systems have started to be assembled. The underground deployment of LZ is scheduled for 2019 and commissioning is expected to start in the beginning of 2020. In parallel with the detector construction and deployment, an intense activity of simulation, R&D of data analysis tools, their implementation and validation is taking place.
Neutrino - Neutrino PhysicsNeutrinos e matéria escura
Neutrinos, the puzzling elementary particles with neutral electric charge and tiny mass, are among the most abundant particles in the Universe, a billion times more than the matter particles that make up stars and galaxies. However, they interact with matter very rarely, and as such they are very difficult to detect and study. We know today that there are 3 different types of neutrinos and they can transform into one another via the quantum process of "neutrino oscillations", only possible if neutrinos have a non-zero mass. This was observed by the Sudbury Neutrino Observatory (SNO) and the Super-Kamiokande experiments, solving the problems of the "missing solar neutrinos" and the "missing atmospheric neutrinos", and leading to the 2015 Nobel Prize in Physics. Since then, other experiments have confirmed the effect with neutrinos created by particle accelerators and nuclear reactors. Besides this unique behavior, it is possible that neutrinos are Majorana particles, i.e. that a neutrino is its own anti-particle, with potential implications on the explanation of the matter/anti-matter asymmetry in the universe.
The LIP Neutrino Physics group is involved in the currently operating SNO+ experiment, and in DUNE, one of the leading neutrino physics experiment for the next decade. The group activities thus combine data analysis with R&D on future detectors.
The LIP group joined the SNO experiment in 2005 and is a founding member of the SNO+ collaboration. The main goal of SNO+ is the search for the neutrinoless double-beta decay of Tellurium-130, but several other physics topics are part of its program: antineutrinos from nuclear reactors and the Earth's natural radioactivity, solar and supernova neutrinos, and searches for new physics. SNO+ reuses the SNO detector located 2 km underground, replacing the 1 kton of heavy water with liquid scintillator, and observing the tiny flashes of scintillation light with an array of 9300 light sensors. The group has participated in the construction of calibration systems, and is currently very active in the analysis of the water phase data, with leadership or strong contributions to physics analyses (backgrounds and antineutrino studies), calibrations, and data quality. The scintillator fill is currently underway, and so the group's efforts will gradually shift from water phase to scintillator phase data analysis.
In 2018, the group joined the DUNE collaboration, that aims to measure one of the missing parameters of neutrino oscillations, the "CP violation phase". This will tells us how different is the behavior of neutrinos and anti-neutrinos and also has strong implications on the explanation of the matter/anti-matter asymmetry in the universe. For that, neutrino and anti-neutrino beams will be produced at Fermilab and detected both near the origin and 1300 km away at an underground laboratory in South Dakota, in large high precision detectors using liquid argon. DUNE also has additional physics goals, such as the measurement of supernova neutrino bursts and the search for proton decay. The beam is expected in 2026, and the first detector installation in 2025 but R&D with large detector prototypes (ProtoDune) is ongoing at CERN. Our activities will initially focus on design of the far detector calibration systems and operation/data analysis of the ProtoDUNE detectors at CERN.
NEXT - High Pressure Xenon Doped Mixtures for the NEXT CollaborationNeutrinos e matéria escura
SHiP - Search for Hidden ParticlesNeutrinos e matéria escura
The SHiP experiment is being designed to search for extremely feebly interacting, relatively light and long-lived particles, at the intensity frontier. The experiment will be located in a new beam dump facility at CERN where it will use the high-intensity beam of 400 GeV/c protons from the SPS accelerator. Presently SHiP is a CERN recognized collaboration of about 300 Physicists from 54 Institutes and 18 Countries. The experiment is expected to be approved by middle of 2020 to start taking data in 2027.
The main goal of SHiP is to explore the so-called Hidden Sector of particle physics in a region of the phase space that is not accessible to the LHC experiments. A wide variety of models predict the existence of new long-lived and feebly interacting particles, which act as "portals" between the Hidden and Standard Model sectors of particle physics and can accommodate a natural explanation for the origin of neutrino masses and oscillations, the nature of dark matter, the origin of matter-antimatter asymmetry in the Universe and inflation. SHiP will address all these unanswered mysteries with unprecedented sensitivity, in a mass region below 10 GeV/c2, using neutrino (heavy neutral leptons), vector (dark photons), scalar and ALP (Axion-Like Paricles) portals. The search for light supersymmetric particles is also part of the physics program. SHiP is being proposed as a discovery experiment but it also includes a rich program of tau neutrino physics, measurements on neutrino-induced charm production and the study of the proton structure with neutrino beams.
The LIP-SHiP group was created in 2018 with the aim of developing an RPC based timing detector, to be placed in the Hidden Sector Spectrometer or in the Neutrino Spectrometer, and also to participate in its physics program. Besides the hardware developments, the group is contributing to the study of neutrino-induced and muon-induced backgrounds and also to the implementation in the simulation and reconstruction software of an ALP → γγ. An ALP with a mass of about 1 GeV/c2 is regarded as an ideal inflaton candidate. The detection of the above mentioned decay would represent a reproduction in the laboratory of the reheating phase of the early Universe.
RPC R&D - Resistive Plate Chambers (RPC)Desenvolvimento de Detectores para Física de Partículas e Nuclear
Resistive Plate Chambers (RPC) are versatile detectors with a fast response, intrinsically radiation hard, and relatively low cost. Over the last years, LIP’s RPC R&D group developed a set of coherent and ambitious lines of work that took the performance and the flexibility of RPCs to a new level. This expanded the range of RPC applications to several areas widely recognized as addressing societal challenges, from nuclear and particle physics to medical physics, from rugged outdoor muon detection systems to helium-free neutron detectors, confirming LIP as a world leader in the development, design and construction of RPCs.
Time-Of-Flight RPCs (TOF-RPCs) continue to be one of the main technologies for particle identification in high energy physics experiments, whenever large detection areas are needed. The group is developing this technology based on an innovative concept for the construction of RPCs, achieving a reasonably low cost and reaching 98% efficiency with 50 ps time resolution. Such detectors are developed for particle physics experiments in which LIP participates, namely HADES and SHiP, but the technology also finds direct application for example in muon tomography, when millimeter position meassuerment is simulteneously meassured. Both transmission tomography (e.g. volcano and mine imaging) and scatter tomography (container scanning) are of interest to the group. As an example, a 4-layer TOFtracker device for muon tomography of cargo containers at harbours, for the HYDRONAV S.A company, has been constructed, integrated and deployed.
Another line of work is the development of RCP-based devices for medical imaging through Positron Emission Tomography (PET). The RPC-PET technology has already been applied successfully in pre-clinical PET. A high-resolution, small animal RPC-PET scanner developed at LIP is installed at ICNAS since 2014. Hundreds of tests have been performed on mice, with goals such as studying the molecular mechanisms underlying degenerative diseases or testing new drugs that may be used to treat certain diseases. This technology has the potential to be applied in human brain PET and change the paradigm in the diagnosis and investigation of diseases of the central nervous system, and to play an important role in the characterization of vascular injuries due to the reachable spatial resolution. A project “HiRezBrainPET: neurofunctional cerebral imaging by high resolution positron emission tomography (PET)” has been submitted and approved. It is led by the company ICNAS-Produção Unipessoal and has a strong participation of LIP.
Autonomous RPCs, able to operate outdoors, reliable, performant, and solar panel powered, are an extremely interesting technology for cosmic ray experiments. The construction, test and deployment on the Sarmiento de Gamboa scientific vessel of the TRISTAN cosmic ray telescope was accomplished successfully in 2018. Another ongoing project is the construction of the MARTA engineering array, equipping some of the water Cherenkov detectors of the Pierre Auger Observatory with RPCs for calibration and R&D purposes. Sealed RPCs would be a breakthrough in the field, and the LIP group is working towards this goal.
Desenvolvimento de Detectores para Física de Partículas e Nuclear
Neutron Detectors - Neutron detectorsDesenvolvimento de Detectores para Física de Partículas e Nuclear
Neutrons as a non-ionizing radiation cannot be detected directly, but only through the reaction products in converter materials. Only a few isotopes can be used for this purpose, with 3He being the most common. However, the 3He shortage results in a change of paradigm, and there is today a widespread need for 3He-free Position Sensitive Neutron Detectors (PSNDs) with enhanced performance for applications ranging from neutron scattering science to homeland security. The European Spallation Source (ESS), currently under construction, is a prime example and a driver of such need for high performance PSNDs to fully explore its potential.
10B is one of the most promising alternatives to 3He. However the maximum detection efficiency achieved with a single layer of a solid neutron converter such as 10B4C is only about 5%. As a solution, the LIP team proposed a new detector concept based on 10B4C coated RPCs, which takes advantage of the naturally layered configuration of RPCs. The feasibility of the concept was successfully demonstrated, and the work developed at LIP is now integrated into the Horizon-2020 EU research project Science & Innovation with Neutrons in Europe in 2020 (SINE2020).
Our studies demonstrate that 10B-RPCs can offer a unique combination of characteristics: very high spatial (FWHM<250 μm) and temporal (sub-nanosecond) resolution, high detection efficiency (>50%), strong design modularity, good scalability, robustness and low price per unit area. To make these detectors s a competitive technology for future applications, the near-future objectives are to enhance the already demonstrated counting rate (~103 Hz/cm2) by two orders of magnitude and to achieve a neutron/gamma rejection factor better than 105.
Gaseous Detectors R&D - Gaseous Detectors R&DDesenvolvimento de Detectores para Física de Partículas e Nuclear
The Gaseous Detectors R&D Group at LIP studies the performance of gas detectors in the challenging range of low energy (below a few hundred keV), and more recently also in the high energy range (of a few MeV). Its main research areas at the moment are the study of the drift parameters of electrons and ions in the gases used as detector’s fillings (noble gases and their mixtures with moleccular ones), with the purpose of finding the more suitable one for each application, namely for large volume detectors or low-energy range ones. Custom made Monte Carlo simulation software specifically developed for the study of these parameters is used to compare and explain the experimental results obtained with the equipment that exists in the lab. This equipment was mainly developed by the group and includes gas detector prototypes and also experimental systems to measure the required drift parameters, namely ion and electron mobility and also electron diffusion.
The group knowledge in this area is the basis of its involvement in the NEXT collaboration, that uses a high pressure xenon TPC to search for neutrinoless double beta decay, and also in the RD51collaboration at CERN, that aims at developing new techniques in gaseous detectors, for which the knowledge of ion and electron drift parameters is very important.
Desenvolvimento de Detectores para Física de Partículas e Nuclear
Liquid Xenon R&D - Liquid Xenon R&DDesenvolvimento de Detectores para Física de Partículas e Nuclear
There is a number of experiments around the world using liquid xenon as detector medium. These include search for lepton number violating muon decay, dark matter searches, neutrino physics and double beta decay. Although the energy ranges of interest of these experiment are different, they have very much in common from the detection point of view. Our team is focused on the processes triggered by particle interaction with liquid xenon and associated technologies, focusing on giving significant contributions to the future generation of liquid xenon detectors. The scope of our activities encompasses all the electronic, optical and molecular processes generated in a single- or double-phase liquid xenon detector due to particle interactions in the medium.
For the next few years our focus will be on studying satellite signals in liquid xenon double phase electroluminescence TPCs in the framework of the recently funded project for participation in the RD51 Collaboration at CERN.
Desenvolvimento de Detectores para Física de Partículas e Nuclear
RPC-PET - PET with Resistive Plate Chambers (RPC-PET)Instrumentos e Métodos para Aplicações Biomédicas
Aim of the project
Positron Emission Tomography (PET) is a powerful diagnostic technique employed in functional medical imaging (molecular imaging). Our overall objective is to develop a radically new technology for TOF PET systems targeted at human whole-body scanning, with resolution down to the physical limit of the PET technique and with a sensitivity improved by over one order of magnitude with respect to current commercial systems, without increase in cost. Such breakthrough would provide physicians with superior capabilities for diagnosing and detecting oncological and other diseases and investigating disease mechanisms, potentially allowing a paradigm shift in PET clinical use.
As the basic feasibility studies have been already carried out, this project specifically aims at designing building, testing and developing a first prototype of a full-size human whole body TOF-PET scanner with a field-of-view of 2 m and a borehole of 90 cm (Fig. 1).
The demonstration of this technology, offering a radically different alternative to crystal-based gamma detection systems, may open totally new avenues for future research in large-area gamma detection, even beyond medical applications.
Sensitivity is a fundamental parameter of PET systems. It determines the amount of radioactive tracer to be administered to the patient, the observation time and the noise level in the image for a given image granularity. Any improvement in system sensitivity will allow a corresponding improvement in one of these parameters or in a combination of them.
However, a practical view should be kept in that a successful new technology should provide the expected benefits without any significant increase in cost over the presently available commercial systems. This is by far not evident with many of the currently researched approaches and some compromise may be necessary [ERI06].
Our proposal for high-sensitivity PET at reasonable cost involves the TOF-PET technique along with a dramatic extension of the FOV [BLA03, ERI08], up to whole-body size (2 m), using a low-cost per unit area particle detector, with excellent spatial resolution, uniform in the Field-of-View owing to its Depth-of-Interaction capability and time-of-flight resolution of 300 ps.
Furthermore, a very large field-of-view, taking the whole image simultaneously (single-bed), has supplementary potential advantages over narrow-FOV PET. These include the possibility of imaging simultaneously the whole body, allowing a more complete study of dynamic processes, covering the whole subject at any given instant with a better temporal segmentation. Other advantages include the possibility of achieving better quantitation through improved scatter correction, since there is no activity outside the FOV.
Our approach is based on a detector technology already used in High Energy Physics Experiments for time-of-flight measurements on charged elementary particles: timing Resistive Plate Chambers (tRPCs). Such gaseous detectors have been deployed in areas over one hundred square meters at reasonable cost, while generally providing an excellent time resolution below 100 ps rms.
Several years ago our group proposed that such detectors might find useful application in TOF-PET technology, both for whole-body human scanning and small animal imaging [BLA03]. The application is based on the "converter plate" principle and takes decisive advantage of the naturally layered structure of tRPCs and of its economic construction in large areas. The expectable low efficiency for 511 keV photons is more than offset [COU07a, ERI08, CRE09] by the possibility to afford a very large field of view (FOV), on the order of 2 m.
The concept has also been independently reviewed [ERI08], although on a different set of assumptions, confirming that it may replace with advantage the present state-of-the-art crystal-based scanners for whole-body scanning.
[BLA03] Perspectives for positron emission tomography with RPCs, Blanco, A; Chepel, V; Ferreira-Marques, R; Fonte, P; Lopes, M.I; Peskov, V; Policarpo, A., Nucl. Instrum. and Meth. A 508 (2003) 88-93.
[COU07a] RPC-PET status and perspectives, M.Couceiro, A.Blanco, Nuno C.Ferreira, R.Ferreira Marques, P.Fonte, L.Lopes., Nucl. Instrum. and Meth. A 580 (2007) 915-918.
[CRE09] Whole-body single-bed time-of-flight RPC-PET: simulation of axial and planar sensitivities with NEMA and anthropomorphic phantoms, P. Crespo et al., 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC), Jan 2010, Page(s): 3420 - 3425
[ERI06] Future instrumentation in positron emission tomography, L. Eriksson et al., 2006 IEEE Nuclear Science Symposium Conference Record, Volume 4, Oct. 29 2006-Nov. 1 2006 Page(s): 2542 - 2545.
[ERI08] Potentials for large axial field of view positron camera systems, L. Eriksson et al., 2008 IEEE MIC Conference, published in the Conference Record.
OR Imaging - Orthogonal Ray Imaging for Radiotherapy ImprovementInstrumentos e Métodos para Aplicações Biomédicas
This is LIP’s core project in instrumentation for radiation therapy, and is developed in partnership with one Portuguese Oncology Institute, the Hospital of the University of Coimbra, and several medical research centers. The aim is to improve radiotherapy by optimizing the treatment in near real time, so that the irradiation can better accommodate the tumor and spare surrounding healthy tissue. To do this, we use X- or gamma-rays emitted orthogonally to the treatment beam.
The OR Imaging technique may be divided into two main branches: OrthoCT (orthogonal computer tomography) for monitoring radiotherapy (high-energy x-rays); and O-PGI (orthogonal prompt-gamma imaging) for monitoring proton therapy. The LIP team pursues the two lines of research.
As an example of recent progress, the results of the analysis of a cavity irradiated inside an acrylic, cylindrical phantom using a small-scale OrthoCT system recently proved for the first time that it is possible to obtain images of the interior of an object without rotating the X-ray source. As for O-PGI studies, a multi-leaf collimator has been fully optimized using Geant4 simulation and our own reconstruction routines. The optimization was based on the analysis of images obtained after the irradiation of the NCAT phantom (cardiac-torso anthropomorphic phantom) with realistic, therapeutic proton beams. The most difficult of the three scenarios considered was the irradiation of the pituitary gland. Here, edematous tissue may account for a Bragg peak shift as small as 2 mm, which the O-PGI system was able to discriminate clearly. Work is now ongoing in order to devise an optimum crystal granularity and positioning so that the 2-mm resolving power is maintained with a realistic O-PGI system. Organ motion (e.g. lung) and vertebra motion in pediatric total body irradiation will also be analyzed via Monte Carlo simulations.
Gamma Cameras - Adaptive methods for medical imaging with gamma camerasInstrumentos e Métodos para Aplicações Biomédicas
The group was created in 2013 to apply the know-how accumulated at LIP in the course of previous work on position-sensitive scintillation detectors (PSSD) to the areas of medical imaging and imaging techniques used in drug discovery.
In the past years we confirmed, both with Monte Carlo simulation and experimentally, the applicability of our auto-calibration and position reconstruction techniques to both clinical gamma cameras of classical design and compact, high-resolution cameras with silicon photomultiplier (SiPM) readout. We also created an integrated software tool that incorporates the whole development workflow for PSSD: interactive design and simulation via a computer model, as well as experimental data processing and event reconstruction.
Our group has close collaborations with the ICNAS and AIBILI medical research centres in Coimbra, with the Coimbra University Hospital Centre (CHUC), and with the Radiation Detectors and Applications Group at Politecnico di Milano, Italy.
STCD TagusLIP - Spin-off technologies for Cancer DiagnosticsInstrumentos e Métodos para Aplicações Biomédicas
The group on Spin-off Technologies for Cancer Diagnosis (STDC) was created ten years ago around the development of a new Positron Emission Tomography scanner (ClearPEM) for breast cancer diagnosis, exploiting technologies developed at LIP for the CMS experiment at the Large Hadron Collider.
Scientific research, technological development and laboratory testing of new PET scanners is pursued at the laboratory infrastructure TagusLIP, dedicated to the development of new nuclear medicine technologies. The TagusLIP infrastructure is installed at Taguspark.
The ClearPEM project was developed by a national consortium of research institutes and clinical centers under the LIP leadership. The consortium is formed by institutions specialized in the areas of physics, nuclear medicine, radiation detectors, biophysics, medical engineering, electronics, computing, mechanical engineering and robotics, and by the start-up company PETsys, which collaborated to develop new technologies applied to cancer detection.
The ClearPEM consortium collaborated in the development of multi-modality imaging systems integrating PET and Ultra-Sound with institutes of the international Crystal Clear Collaboration, namely CERN Switzerland, INFN-Milano Italy, Univ. Hospital Nord Marseille France, Hospital San Gerardo Monza Italy.
Since 2011 the LIP/STCD group is part of the consortium EndoTOFPET funded by the FP7 framework program of the European Union. This project is being developed until July 2015 with the aim of developing an endoscopic PET and ultrasound probe, associated with an external PET detector for detection of prostate and pancreatic cancer. LIP coordinates the Work Package 4, responsible for the electronics and data acquisition systems.
The LIP/STCD group is part of the FP7 Marie Curie Training Network (ITN) PICOSEC, focused in the development of sensors with very good time resolution for Time-of-Flight PET.
Dosimetry - DosimetryInstrumentos e Métodos para Aplicações Biomédicas
The exposure to ionizing radiations can happen due to natural or human causes. The purpose of dosimetry is the measurement and control of the amount of radiation absorbed by a body when irradiated. Dosimetry finds application in the most varied fields: environment and public health, diagnosis and treatment facilities in hospitals (patients and clinical staff), manned and unmanned space missions, industrial facilities.
Over the last 20 years the interest in the use of protons for radiation therapy treatments has grown steadily. More recently facilities dedicated to proton therapy were created in a number of places in Europe. Protons have advantages over photons on what concerns tumor therapy, being particularly helpful for the treatment of deep-seated tumors located close to critical organs.
LIP has a long term expertise in photon and electron dosimetry. From accelerator simulation to dosimeter prototyping, the work in the field goes back more than two decades. The possibility of the installation of a proton therapy facility in Lisbon opens a window of opportunity for research in this area.
The group is divided into two thematic lines: clinical dosimetry, focusing on the use of plastic scintillators and optical fibers in the context of clinical dosimetry for particle therapy; and high-LET radiation microdosimetry, focusing on the development of radiation detectors able to measure energy deposition at sub-mm scales and on studies of radiation effects at the cell level
Space Rad - Space Radiation Environment and EffectsAmbientes de radiação e aplicações para missões espaciais
In the past 15 years, an area of research and development focused on the study of the radiation environment in space and its effects was created and consolidated at LIP. The work developed is in line with the ESA roadmap for the area of "Space Radiation environment and Effects", with all the competences developed in this field at LIP encompassing all the technologie identified by ESA. LIP is therefore a national academic and R&D reference in these areas, which are:
1. Environment analysis & Modelling: development and improvement of radiation belt models; development of radiation environment models for specific locations in the solar system; study and description of radiation environments due to solar emissions and galactic cosmic radiation.
2. Radiation Effects Analysis tools: development of tools enabling precise and user friendly radiation shielding and effects calculations, including the induction of single event effects (SEE) in the electronic components that support the systems of satellites and space missions.
3. Radiation measurement: development of ionising radiation measurement technologies and methods.
4. Radiation Hardness Assurance: investigation of the effects of radiation on new types of electronic components and in mission and satellite dependent environments, both for total ionizing dose (TID) and for single effect effects (SEE); development of test facilities with particle beams and radiation sources; development and exploration of in-flight experiments and tests and of methodologies for radiation hardeness assurance (RHA) and evaluation of radiation effects in biological systems and for human space flight.
In its activities, mostly developed under contracts with ESA, LIP has worked with different national and international entities, both from academia and industry.
i-Astro - Space Instrumentation for AstrophysicsAmbientes de radiação e aplicações para missões espaciais
in the framework of mission proposals to ESA and NASA in the X- and gamma-ray domains. The group is part of All-Sky-ASTROGAM, AMEGO (All-sky Medium Energy Gamma-ray Observatory) and IXPE (Imaging X-ray Polarimetry Explorer) space missions consortia. Our group is contributing to the development of detection plane instruments based in CdTe, CZT, CsI, Si and in gas filled detectors with spectroscopic, imaging and polarimetric capabilities. These missions will address the new multi-messenger astrophysics domain, where gravitational waves’ observation in ground facilities, such as LIGO-Virgo, coordinated with simultaneous gamma-ray transients’ observations performed in such gamma-ray space missions may provide useful constraints on the gravitational wave source localization. Polarimetry in high-energy astrophysics has known very few developments, therefore the referred missions polarimetric capabilities hold a great potential to open a new scientific observational window.
As examples of recent activities, in the framework of AHEAD we simulated the instrument mass model performances for e-ASTROGAM and AMEGO missions. Polarimetric measurements with a double layer CdTe prototype under a polarized beam were performed at the ESRF (European Synchrotron Radiation Facility) and at LARIX (LARge Italian X-ray facility) facility at the University of Ferrara. We simulated the potential polarimetric performances of different noble gases, in the framework of the development of the main instrument of the IXPE mission. CdTe radiation hardness testing for Space Instrumentation were also carried on, in order to characterize the effects of Low-Earth Orbit (LEO) proton radiation environment on CdTe based instruments.
Outreach Stratospheric Spectropolarimeter Gamma-X balloon experiment was launched the September 4th, 2018 in NASA HASP (High Altitude Student Platform) facilities at Fort Sumner, New Mexico, USA. i-Astro is also organising the How to be an Astronaut Summer School for secondary school students and the Portugal Space Summer School for university students.
GRID - Distributed Computing and Digital InfrastructuresComputação Científica
The activities in the computing infrastructures domain encompass the support to scientific research, the participation in R&D projects aimed to keep LIP in the forefront of IT technologies, and the participation in digital infrastructure initiatives. These activities are mainly focused on grid computing, cloud computing and on big data challenges.
LIP is member of the Portuguese National Distributed Computing Infrastructure (INCD) in partnership with LNEC and FCCN. INCD is a digital infrastructure approved in the context of the Portuguese Science Foundation (FCT) strategic infrastructures roadmap. INCD provides computing and data services to the national scientific and academic community in all domains. It supports researchers and their participation in national and international research projects.
LIP participates actively in several international computing infrastructures acting as national contact point, namely: Worldwide LHC Computing Grid (WLCG), European Grid Infrastructure (EGI), Iberian Grid Infrastructure (IBERGRID).
LIP has been participating in many R&D projects in the context of the European framework programme, among them the recent: EGI-INSPIRE (FP7), EGI–ENGAGE (H2020), INDIGO-DATACLOUD (H2020), EOSC-hub (H2020), DEEP-Hybrid-DataCloud (H2020) and EOSC-synergy (H2020).
Advanced Computing - Advanced ComputingComputação Científica
Members of Advanced Computing Group have previous work in Grid, HPC, computing models, high performance communication libraries and distributed data structures. Research also encompasses R&D on the combination of traditional multicore CPUs with acceleration devices.
The group, part of the LIP-Minho since the beginning of 2014, has been directing its activity to the fields of Computer Science and Engineering more closely related to areas particularly interesting for LIP´s research. Noteworthy are the support to the development and optimization of code applications related to high energy physics, and the search for explicit distribution strategies for access to large data volumes in order to improve efficiency and execution times.
More recently the group embraced topics related to the areas of big data and machine learning. Another important dimension of the group’s activity is the support to advanced training in Scientific Computing. The group is also responsible for the administration of a local HPC cluster that supports the running of the data analysis applications developed by other groups in LIP and a CPU/GPU system dedicated to machine learning simulations.
SPAC - Social Physics and ComplexityComputação Científica
SPAC uses large scale computational tools to study societal challenges, especially in disease forecasting, human behavior and public policy. This multidisciplinary research group takes advantage of the so-called “Big-Data Revolution” and works together to understand how individual behaviour impacts on society. We also focus on the risks that these technologies might entail and we help establish the guidelines for ethical uses of data science and artificial intelligence. The European Research Council has awarded a Starting Grant to the group PI to conduct the research project “Fake News and Real People – Using Big Data to Understand Human Behaviour (FARE)”.
Understanding complexity has always been a hallmark of physics research and, through theory, experiments, and models, physicists have made fundamental contributions to many different complex fields. Right now, the so-called Digital Revolution is offering radically new ways to study complex behaviours and this is being recognized by physics and computer science departments in many top universities worldwide. Complexity Science (CS) studies complex systems and tries to identify general principles. Complex systems consist of a large number of interacting heterogeneous components (parts, agents, humans etc.), resulting in highly non-linear and unpredictable behaviour, with emergence properties. CS theory typically builds on statistical physics and dynamical systems, but also on information theory and, increasingly, network science.
The combination of large-scale data sources and a growing toolbox from machine learning and big data analytics, is making it easier to extract patterns and offer some predictions. In fact, many of the methods developed by statistical and particle physics are now being applied to societies and there is a growing perception that physics will be fundamental to study sociology and even psychology. Leading scientists are calling this new science “Social Physics” and arguing that, in some ways, complexity science will study the physics of human interactions.