This second open access volume of the handbook series deals with detectors, large experimental facilities and data handling, both for accelerator and non-accelerator based experiments. It also covers ...applications in medicine and life sciences. A joint CERN-Springer initiative, the “Particle Physics Reference Library” provides revised and updated contributions based on previously published material in the well-known Landolt-Boernstein series on particle physics, accelerators and detectors (volumes 21A,B1,B2,C), which took stock of the field approximately one decade ago. Central to this new initiative is publication under full open access.
"Big" science and advanced technology are known to cross-fertilize. This book emphasizes the interplay between particle physics and technology at CERN that has led to breakthroughs in both research ...and technology over the laboratory's first 60 years. The innovations, often the work of individuals or by small teams, are illustrated with highlights describing selected technologies from the domains of accelerators and detectors. The book also presents the framework and conditions prevailing at CERN that enabled spectacular advances in technology and contributed to propel the European organization into the league of leading research laboratories in the world. While the book is specifically aimed at providing information for the technically interested general public, more expert readers may also appreciate the broad variety of subjects presented. Ample references are given for those who wish to further explore a given topic.
Future high-energy physics (HEP) experiments as well as next generation medical imaging applications are more and more pushing towards better scintillation characteristics. One of the problems in ...heavy scintillating materials is related to their high electronic density, resulting in a large index of refraction. As a consequence, most of the scintillation light produced in the bulk material is trapped inside the crystal due to total internal reflection. The same problem also occurs with light emitting diodes (LEDs) and has for a long time been considered as a limiting factor for their overall efficiency. Recent studies have shown that those limits can be overcome by means of light scattering effects of photonic crystals (PhCs). In our simulations we could show light yield improvements between 90% and 110% when applying PhC structures to different scintillator materials. To evaluate the results, a PhC modified scintillator was produced in cooperation with the NIL (Nanotechnology Institute of Lyon). By using silicon nitride (Si
3N
4) as a transfer material for the PhC pattern and a 70
nm thick Indium Tin Oxide (ITO) layer for the electrical conductivity during the lithography process, we could successfully fabricate first samples of PhC areas on top of LYSO crystals.
Photonic crystals (PhCs) are optical materials which can affect the propagation of light in multiple ways. In recent years PhCs contributed to major technological developments in the field of ...semiconductor lasers, light emitting diodes and photovoltaic applications. In our case we are investigating the capabilities of photonic crystal slabs with the aim to improve the performance of heavy inorganic scintillators. To study the combination of scintillators and PhCs we use a Monte-Carlo program to simulate the light propagation inside a scintillator and a rigorous coupled wave analysis (RCWA) framework to analyse the optical PhC properties. The simulations show light output improvements of a wide range of scintillating materials due to light scattering effects of the PhC slabs. First samples have been produced on top of 1.2 × 2.6 × 5 mm LSO (cerium-doped Lutetium Oxyorthosilicate, Lu 2 SiO 5 : Ce 3+ ) scintillators using electron beam lithography and reactive ion etching (RIE). Our samples show a 30-60% light output improvement when compared to unstructured reference crystals which is in close accordance with our simulation results. In addition, a theoretical investigation of the restrictions of the current PhC sample is given which concludes with prospects for improved future designs.
A major challenge for future particle physics experiments and nuclear medicine imaging applications will be the improvement of energy and time resolution of the detector systems. Both parameters are ...strongly correlated with the number of photoelectrons which can be registered after a particle has deposited its energy in the scintillator. One problem in heavy scintillating materials is that a large fraction of the light produced inside the bulk material is trapped inside the crystal due to total internal reflection. Recent developments in the area of nanophotonics show that those limitations can be overcome by introducing a photonic crystal (PhC) slab at the outcoupling surface of the scintillator. Photonic crystals are optical materials which can affect the propagation of light in multiple ways. In this work, the PhC is used for the extraction of photons which are otherwise reflected within the scintillator. Our simulations show light output improvements for a wide range of scintillating materials due to light scattering effects of the photonic grating. In the practical part of the work we show how we were producing first samples of PhC slabs on top of different scintillators to confirm the simulation results by measurements. Through the deposition of an auxiliary layer of silicon nitride and the adaptation of the standard electron beam lithography (EBL) parameters we could successfully produce several PhC slabs on top of 1.2 mm × 2.6 mm × 5 mm lutetium oxyorthosilicate (LSO) scintillators. In the characterization process we show a 30-60% light yield improvement of the different PhC designs when compared to an unstructured reference scintillator, which is also in close accordance with our simulation results.
ALICE-An LHC Ion Collider Experiment-is being prepared to study, in an optimized and dedicated approach, the physics of nuclear matter under extreme conditions of temperature and density. The LHC Ion ...programme is the logical sequel in the quest to study the novel form of matter, the Quark-Gluon Plasma, the form of matter believed to have existed in our Universe during the first microsecond after the Big Bang. The status of ALICE, its research programme and discovery potential are presented.
Over the past 15 years a worldwide Detector R&D Programme has made the LHC experiments possible. These experiments operate at a new level of event rate and detection capabilities. Based on these ...advances, Detector R&D is continuing at CERN in close collaboration with University and Research Institutes. Several main directions are being pursued for solid-state and gaseous tracking devices, advanced crystal and noble liquid calorimetry, particle identification methods, and advanced signal-processing techniques. This effort is directed towards experiments at even higher collision rates at the LHC, the requirements for the next generation of linear electron-positron colliders and for applications outside particle physics, such as medical diagnostics instrumentation. We shall illustrate this challenging, stimulating and creative programme with examples and show how these developments are taking place in close collaboration between CERN and institutions around the globe.
Application of protective coatings is the most widely used conservation treatment for outdoor bronzes. Eco-friendly and non-hazardous coatings are currently needed for conservation of outdoor bronze ...monuments. To fulfil this need, the M-ERA.NET European research project B-IMPACT (Bronze-IMproved non-hazardous PAtina CoaTings) aimed at assessing the protectiveness of innovative coatings for historical and modern bronze monuments exposed outdoors. In this project, two bronze substrates (historical Cu-Sn-Zn-Pb and modern Cu-Si-Mn alloys) were artificially patinated, by acid rain solution using dropping test and by "liver of sulphur" procedure (K2S aqueous solution) to obtain black patina, respectively. Subsequently, the application of several newly developed protective coatings was carried out and their performance was investigated by preliminary electrochemical tests. In the following steps of the work, the assessment of the best-performing coatings was carried out and their performance was compared to Incralac, one of the most widely used protective coatings in conservation practice. A multi-analytical approach was adopted, considering artificial ageing (carried out in representative conditions, including exposure to rain runoff, stagnant rain and UV radiation) and metal release, as well as visual aspect (so as to include aesthetical impact among the coating selection parameters) and morphological and structural evolution of the coated surfaces due to simulated outdoor exposure. Lastly, also the health impact of selected coatings was assessed by occupational hazard tests. The removability and re-applicability of the best-performing coatings were also assessed. The best alternatives to the conventional Incralac exhibited were: (i) fluoroacrylate blended with methacryloxy-propyl-trimethoxy-silane (FA-MS) applied on patinated Cu-Sn-Zn-Pb bronze and (ii) 3-mercapto-propyl-trimethoxysilane (PropS-SH) applied on patinated Cu-Si-Mn bronze.
In this paper Monte Carlo simulations (FLUKA) and measurements of the response of a BGO detector are reported. For the measurements three low-energy photon emitters (
60Co,
54Mn,
137Cs) were used to ...irradiate the BGO from various distances and angles. The neutron response was measured with an Am–Be neutron source. Simulations of the experimental irradiations were carried out. Our study can also be considered as a benchmark for FLUKA in terms of its reliability to predict the detector response of a BGO scintillator.
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