F. Fiori

The first phase of a study of GaAs as a base material for solid-state detectors has been completed. The main motivation behind this study is the greater radiation resistance of integrated circuits made of GaAs (compared with Si). Many diodes, of different sizes and shapes but built with the same technique, have been tested electrically and as detectors, using α sources and minimum-ionizing particles. The tests show that these devices work with a full detection effeciency, although there is evidence for trapping of a fraction of the charge produced by the particle inside the semiconductor.

We report on progress with Schottky diode and p-i-n diode GaAs detectors for minimum ionising particles. The radiation hardness and potential speed of simple diodes is shown to be more than competitive with silicon detector. A discussion is given of the present understanding of the charge transport mechanism in the detectors since it influences their charge collection efficiency. Early results from microstrip detectors are also described.

In current particle physics experiments, silicon strip detectors are widely used as part of the inner tracking layers. A foreseeable large-scale application for such detectors consists of the luminosity upgrade of the Large Hadron Collider (LHC), the super-LHC or sLHC, where silicon detectors with extreme radiation hardness are required. The mission statement of the CERN RD50 Collaboration is the development of radiation-hard semiconductor devices for very high luminosity colliders. As a consequence, the aim of the R&D programme presented in this article is to develop silicon particle detectors able to operate at sLHC conditions. Research has progressed in different areas, such as defect characterisation, defect engineering and full detector systems. Recent results from these areas will be presented. This includes in particular an improved understanding of the macroscopic changes of the effective doping concentration based on identification of the individual microscopic defects, results from irradiation with a mix of different particle types as expected for the sLHC, and the observation of charge multiplication effects in heavily irradiated detectors at very high bias voltages.

Renewable heating systems (RHS), such as solar thermal, geothermal, heat pumps, wood pellets, biomass, are essential to reduce dependence on fossil fuel-based heating systems and resulting CO2 emissions. Despite their benefits in terms of CO2 emissions, the widespread adoption of RHS has yet to be achieved. This paper aims to get insights into the intention to adopt RHS in the Netherlands For this purpose, it designs and conducts a survey based on the extended version of the theory of planned behavior, with five components: attitude, subjective norms, perceived behavioral control, personal norms, and descriptive norms. The survey also includes questions on participation in a thermal energy community. The results show that several factors affect individuals' intention to adopt RHS. Many individuals in the Netherlands have a positive attitude toward adopting RHS, which is primarily caused by environmental concerns and wanting energy independence for their country. However, the majority of individuals think that they do not have the knowledge, financial means, or time to adopt RHS. Also, individuals who feel strong moral values and responsibilities are more likely to adopt RHS. Most individuals are willing to participate in a thermal energy community, and prefer participating in an energy community over adopting RHS individually. Based on these insights, a number of recommendations are made to stimulate the adoption of RHS in the Netherlands, such as taking into account moral norms, introducing policies to incentivize thermal energy communities, and addressing issues of injustice.

A gas vertex detector, operated with dimethylether (DME) at atmospheric pressure, is presently being built for the ZEUS experiment at HERA. Its main design features, together with the performances of a prototype measured at various operating voltages, particle rates and geometrical conditions on a CERN Proton Synchrotron test beam, are presented. A spatial resolution down to 35 μm and an average wire efficiency of 96% have been achieved, for a 3 mm gas gap relative to each sense wire.

Motivated by the success of the flavour physics programme carried out over the last decade at the Large Hadron Collider (LHC), we characterize in detail the physics potential of its High-Luminosity and High-Energy upgrades in this domain of physics. We document the extraordinary breadth of the HL/HE-LHC programme enabled by a putative Upgrade II of the dedicated flavour physics experiment LHCb and the evolution of the established flavour physics role of the ATLAS and CMS general purpose experiments. We connect the dedicated flavour physics programme to studies of the top quark, Higgs boson, and direct high-$p_T$ searches for new particles and force carriers. We discuss the complementarity of their discovery potential for physics beyond the Standard Model, affirming the necessity to fully exploit the LHC's flavour physics potential throughout its upgrade eras.

The GaAs detectors for minimum ionizing particles fabricated with commercial undoped SI GaAs show good quality as minimum ionizing particle detectors. A discussion is given of the present understanding of the charge transport mechanism in the detectors since it influences their charge collection efficiency.

The charge collected from p-type silicon strip sensors irradiated to SuperLHC fluences has been determined with a beta source using fast front-end electronics. The bias voltage dependence of the collected charge and the hit detection efficiency have been measured before and after accelerated annealing. Predictions of the performance at the SuperLHC are derived.

Progress with Schottky diode and p i n diode GaAs detectors for minimum ionizing particles is reported here. The radiation hardness and potential speed of simple diodes is shown to be more than competitive with silicon detectors. A discussion is given of the present understanding of the charge transport mechanism in the detectors as it influences their charge collection efficiency. Early results from micro-strip detectors are also described, (which are relevant for high radiation regions of LHC detectors near the beam pipe and in the forward region).

The charge collected from p-type silicon strip sensors irradiated to SuperLHC fluences has been determined in a beta source using fast front-end electronics. The bias voltage dependence of the collected charge and the efficiency have been measured before and after accelerated annealing. Predictions of the performance at the LHC are derived.

Abstract Progress on the development of GaAs solid state detectors is presented. 80% charge collection efficiency has been achieved, and double sided detectors with metal rectifying contacts have been tested. Measurements of capacitance and tests with SEM are giving more information on the behaviour of these devices.

The paper describes a study of the radiation hardness of micro-strip devices, processed on different silicon substrates, designed to explore the feasibility of a tracker system for the experiments upgrade at the Super-LHC (S-LHC) collider. The radiation tolerance of the devices has been established comparing the Charge Collection Efficiency (CCE) measured on irradiated and not irradiated sensors of the same type. The CCE has been measured with minimum ionizing events and the read-out electronics and data acquisition system are the same designed for the CMS experiment at LHC. The performances of different silicon substrates (MCz, Fz, Epi)1 and different bulk doping types (p, n) have been investigated. The radiation hardness has been studied up to a fluence of 3.5×1015neqcm-2, value expected at a radial distance of about 9 cm from the interaction point at S-LHC. Preliminary results of radiation hard candidate material are shown. This work is part of the research activities of INFN SMART and RD50 CERN collaborations.

Experience at high luminosity hadron collider experiments shows that tracking information enhances the trigger rejection capabilities while retaining high efficiency for interesting physics events [F. Palla and G. Parrini, Tracking in the trigger: from the CDF experience to CMS upgrade, 2007. Published in PoS VER-TEX2007:034, 2007]. The design of a tracking based trigger for Super LHC (S-LHC), the already envisaged high luminosity upgrade of the LHC collider, is an extremely challenging task, and requires the identification of high-momentum particle tracks as a part of the Level 1 Trigger. Simulation studies show that this can be achieved by correlating hits on two closely spaced silicon strip sensors. This work focuses on the design and development of micro-strip stacked prototype modules and will also discuss the technical challenges in the construction and the final detector performance. Studies of possible sensor geometries and wire-bonding techniques will be also presented. The prototypes have been built with the silicon sensors and electronics used to equip the present CMS Tracker [CMS Collaboration, The CMS experiment at the CERN LHC, JINST 3:S08004:26-89, 2008]. Correlation of signals collected from sensors are processed off detector. We will present the results of tests performed on the prototype modules in terms of the noise performance of the proposed stack geometry. Preliminary results in terms of signal over noise and tracking performance with cosmic rays will also be shown.

Experience at high luminosity hadrons collider experiments shows that tracking information enhances the trigger rejection capabilities while retaining high efficiency for interesting physics events.The design of a tracking based trigger for Super LHC (S-LHC), the already envisaged high luminosity upgrade of the LHC collider, is an extremely challenging task, and requires the identification of high-momentum particle tracks as a part of the Level 1 Trigger.Simulation studies show that this can be achieved by correlating hits on two closely spaced silicon strip sensors.The progresses on the design and development of this micro-strip stacked prototype modules and the performance of few prototype detectors will be presented.The prototypes have been built with the silicon sensors and electronics used to equip the present CMS[1] Tracker.Preliminary results of a simulated tracker layout equipped with stacked modules are discussed in terms of p T resolution and triggering capabilities.The study of real prototypes in terms of signal over noise and tracking performance with cosmic rays and a dedicated beam test experiment will also be shown.©2011 CERN, for the benefit of CMS Collaboration.

Experience at high luminosity hadron collider experiments shows that tracking information enhances the trigger rejection capabilities while retaining high efficiency for interesting physics events [1]. The design of a tracking based trigger for Super LHC (S-LHC), the high luminosity upgrade of the LHC collider [2], is an extremely challenging task requiring the identification of high-momentum tracks as a part of the Level 1 trigger decision. Simulation studies show that this can be achieved by correlating hits on two closely spaced silicon strip sensors. This paper focuses on the design and development of micro-strip stacked prototype modules and their performance. The prototypes have been built with the silicon sensors and electronics used to equip the present CMS Tracker [3]. Correlation of signals collected from sensors are processed off detector. Preliminary results in terms of signal over noise and tracking performance with cosmic rays will be also shown.

Detectors with a p-i-n structure based on Liquid Encapsulated Czochralski (LEC) grown Semi-Insulating (SI) GaAs have been fabricated. The current-voltage (I–V) characteristics and their response to γ-rays have been studied. Measurements of the peak charge collection efficiency (cce) have been compared with a model assuming a uniform electric field. The comparison indicates that this field is not uniform. The peak cce at 500 V is found to be 52% and 82% in 400 μm and 200 μm thick detectors respectively. The resolution of the 57Co full energy peak is between 10% and 13% at 400 V.

A summary of the results on GaAs detectors for high-energy physics is presented. We have tested about thirty detectors with different geometrical parameters. Most detectors were built evaporating metals on the semiconductor, using a shadow mask. These detectors appear to be very resistant to radiation, particularly to neutrons.

Thermal-hydraulic system computer codes are extensively used worldwide for analysis of nuclear facilities by utilities, regulatory bodies, nuclear power plant designers and vendors, nuclear fuel companies, research organizations, consulting companies, and technical support organizations. The computer code user represents a source of uncertainty that can influence the results of system code calculations. This influence is commonly known as the ‘user effect’ and stems from the limitations embedded in the codes as well as from the limited capability of the analysts to use the codes. Code user training and qualification is an effective means for reducing the variation of results caused by the application of the codes by different users. This paper describes a systematic approach to training code users who, upon completion of the training, should be able to perform calculations making the best possible use of the capabilities of best estimate codes. In other words, the program aims at contributing towards solving the problem of user effect. The 3D S.UN.COP (Scaling, Uncertainty and 3D COuPled code calculations) seminars have been organized as follow-up of the proposal to IAEA for the Permanent Training Course for System Code Users. Eleven seminars have been held at University of Pisa (two in 2004), at The Pennsylvania State University (2004), at the University of Zagreb (2005), at the School of Industrial Engineering of Barcelona (January-February 2006), in Buenos Aires, Argentina (October 2006), requested by Autoridad Regulatoria Nuclear (ARN), Nucleoelectrica Argentina S.A (NA-SA) and Comisión Nacional de Energía Atómica (CNEA), at the College Station, Texas A&M, (January-February 2007), in Hamilton and Niagara Falls, Ontario (October 2007) requested by Atomic Energy Canada Limited (AECL), Canadian Nuclear Society (CNS) and Canadian Nuclear Safety Commission (CNSC), in Petten, The Netherlands (October 2008) in cooperation with the Institute of Energy of the Joint Research Center of the European Commission (IE-JRC-EC), at the Royal Institute of Technology, Stockholm (October 2009), in Petten, The Netherlands (October 2010) in cooperation with the Institute of Energy of the Joint Research Center of the European Commission (IE-JRC-EC) and in 2011 at Wilmington (North Carolina, USA) in cooperation with General Electric Hitachi, Westinghouse, AREVA NP and INL. It was recognized that such courses represented both a source of continuing education for current code users and a mean for current code users to enter the formal training structure of a proposed ‘permanent’ stepwise approach to user training. The 3D S.UN.COP 2011 at Wilmington was successfully held with the attendance of more than 22 participants coming from more than 10 countries and 15 different institutions (universities, vendors and national laboratories). Around 30 scientists (coming from more than 10 countries and 20 different institutions) were involved in the organization of the seminar, presenting theoretical aspects of the proposed methodologies and holding the training and the final examination. A certificate (LA Code User grade) was released to participants that successfully solved the assigned problems. The twelfth seminar will be held (April 2012) in Daejeon, South Korea in cooperation with the “Korea Atomic Energy Research Institute”, involving more than 30 scientists between lecturers and code developers (http://www/nrgspg.ing.unipi.it/3dsuncop/).

Prototype silicon microstrip modules meant to generate Level 1 trigger information in future tracker implementations at super-high luminosity accelerators have been built using spare components from the current CMS Tracker and tested on a 120 GeV muon beam at the CERN SPS North Area. Tracking information from a silicon microstrip beam telescope has also been used in order to precisely reconstruct tracks and incidence angles. Data has been collected from prototypes with different geometries and interconnection schemes and at different angles of beam incidence, simulating the effect of a solenoidal magnetic field on particles of different transverse momentum p <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">⊥</sub> .

This report describes the scientific aims and potentials as well as the preliminary technical design of IRIDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity 'particle factory', based on a combination of a high duty cycle radio-frequency superconducting electron linac and of high energy lasers. Conceived to provide unique research possibilities for particle physics, for condensed matter physics, chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of science and technology. IRIDE will contribute to open new avenues of discoveries and to address most important riddles: What does matter consist of? What is the structure of proteins that have a fundamental role in life processes? What can we learn from protein structure to improve the treatment of diseases and to design more efficient drugs? But also how does an electronic chip behave under the effect of radiations? How can the heat flow in a large heat exchanger be optimized? The scientific potential of IRIDE is far reaching and justifies the construction of such a large facility in Italy in synergy with the national research institutes and companies and in the framework of the European and international research. It will impact also on R&amp;D work for ILC, FEL, and will be complementarity to other large scale accelerator projects. IRIDE is also intended to be realized in subsequent stages of development depending on the assigned priorities.

Experience at high luminosity hadron collider experiments shows that tracking information enhances the trigger rejection capabilities while retaining high efficiency for interesting physics events. The design of a tracking based trigger for Super LHC (S-LHC), the already envisaged high luminosity upgrade of the LHC collider, is an extremely challenging task, and requires the identification of high-momentum particle tracks as a part of the Level 1 Trigger. Simulation studies show that this can be achieved by correlating hits on two closely spaced silicon strip sensors. This work focuses on the design and development of micro-strip stacked prototype modules and will also discuss the technical challenges in the construction and final detector performance. Studies of possible sensor spacing and wire-bonding techniques will be also presented. The prototypes have been built with the silicon sensors and electronics used to equip the present CMS Tracker. Correlation of signals collected from sensors are processed off detector. We will present the results of tests performed on the prototype modules in terms of the noise performance of the proposed stack geometry. Preliminary results in terms of signal over noise and tracking performance with cosmic rays will also be shown.

The CMS Tracker was repaired, recalibrated and commissioned successfully for the second run of Large Hadron Collider. In 2015 the Tracker performed well with improved hit efficiency and spatial resolution compared to Run I and operated smoothly at lower temperatures after the successful recommissioning of the cooling system. This year the detector is expected to withstand luminosities that are beyond its design limits and will need a combined effort of both online and offline team to yield the high quality data that is required to reach our physics goals. We present the experience gained during the second run of the LHC and show the latest performance results of the CMS Tracker.

L’Austria e l’Europa dopo Versailles. Allargare la zona d’influenza. L’austrofascismo. L’Anschluss.

Progress in the development of detectors based on semi‐insulating GaAs for experiments at future hadron colliders is presented. Effects of neutron and gamma irradiation at the levels of 1014 ncm−2 and 20 MRad respectively, have been shown to be small. Testbeam studies have shown that microstrip detectors can detect minimum ionizing particles with a good signal to noise ratio despite having low charge collection efficiencies. The problem of charge loss in the detectors is now better understood and new detectors have shown improved charge collection efficiencies.