439 research outputs found

    Belle II Technical Design Report

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    The Belle detector at the KEKB electron-positron collider has collected almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an upgrade of KEKB is under construction, to increase the luminosity by two orders of magnitude during a three-year shutdown, with an ultimate goal of 8E35 /cm^2 /s luminosity. To exploit the increased luminosity, an upgrade of the Belle detector has been proposed. A new international collaboration Belle-II, is being formed. The Technical Design Report presents physics motivation, basic methods of the accelerator upgrade, as well as key improvements of the detector.Comment: Edited by: Z. Dole\v{z}al and S. Un

    NA61/SHINE facility at the CERN SPS: beams and detector system

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    NA61/SHINE (SPS Heavy Ion and Neutrino Experiment) is a multi-purpose experimental facility to study hadron production in hadron-proton, hadron-nucleus and nucleus-nucleus collisions at the CERN Super Proton Synchrotron. It recorded the first physics data with hadron beams in 2009 and with ion beams (secondary 7Be beams) in 2011. NA61/SHINE has greatly profited from the long development of the CERN proton and ion sources and the accelerator chain as well as the H2 beamline of the CERN North Area. The latter has recently been modified to also serve as a fragment separator as needed to produce the Be beams for NA61/SHINE. Numerous components of the NA61/SHINE set-up were inherited from its predecessors, in particular, the last one, the NA49 experiment. Important new detectors and upgrades of the legacy equipment were introduced by the NA61/SHINE Collaboration. This paper describes the state of the NA61/SHINE facility - the beams and the detector system - before the CERN Long Shutdown I, which started in March 2013

    Operations of and Future Plans for the Pierre Auger Observatory

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    Technical reports on operations and features of the Pierre Auger Observatory, including ongoing and planned enhancements and the status of the future northern hemisphere portion of the Observatory. Contributions to the 31st International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200

    GPU-based Real-time Triggering in the NA62 Experiment

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    Over the last few years the GPGPU (General-Purpose computing on Graphics Processing Units) paradigm represented a remarkable development in the world of computing. Computing for High-Energy Physics is no exception: several works have demonstrated the effectiveness of the integration of GPU-based systems in high level trigger of different experiments. On the other hand the use of GPUs in the low level trigger systems, characterized by stringent real-time constraints, such as tight time budget and high throughput, poses several challenges. In this paper we focus on the low level trigger in the CERN NA62 experiment, investigating the use of real-time computing on GPUs in this synchronous system. Our approach aimed at harvesting the GPU computing power to build in real-time refined physics-related trigger primitives for the RICH detector, as the the knowledge of Cerenkov rings parameters allows to build stringent conditions for data selection at trigger level. Latencies of all components of the trigger chain have been analyzed, pointing out that networking is the most critical one. To keep the latency of data transfer task under control, we devised NaNet, an FPGA-based PCIe Network Interface Card (NIC) with GPUDirect capabilities. For the processing task, we developed specific multiple ring trigger algorithms to leverage the parallel architecture of GPUs and increase the processing throughput to keep up with the high event rate. Results obtained during the first months of 2016 NA62 run are presented and discussed

    Technical Design Report for the PANDA Micro Vertex Detector

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    This document illustrates the technical layout and the expected performance of the Micro Vertex Detector (MVD) of the PANDA experiment. The MVD will detect charged particles as close as possible to the interaction zone. Design criteria and the optimisation process as well as the technical solutions chosen are discussed and the results of this process are subjected to extensive Monte Carlo physics studies. The route towards realisation of the detector is outlined

    The COMPASS Experiment at CERN

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    The COMPASS experiment makes use of the CERN SPS high-intensitymuon and hadron beams for the investigation of the nucleon spin structure and the spectroscopy of hadrons. One or more outgoing particles are detected in coincidence with the incoming muon or hadron. A large polarized target inside a superconducting solenoid is used for the measurements with the muon beam. Outgoing particles are detected by a two-stage, large angle and large momentum range spectrometer. The setup is built using several types of tracking detectors, according to the expected incident rate, required space resolution and the solid angle to be covered. Particle identification is achieved using a RICH counter and both hadron and electromagnetic calorimeters. The setup has been successfully operated from 2002 onwards using a muon beam. Data with a hadron beam were also collected in 2004. This article describes the main features and performances of the spectrometer in 2004; a short summary of the 2006 upgrade is also given.Comment: 84 papes, 74 figure

    R&D for high-momentum hadron identification: from COMPASS RICH towards particle identification at the future Electron Ion Collider

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    Un importante strumento per lo studio della struttura adronica sono le misure di produzione di adroni in processi di Deep Inelastic Scattering Semi – Inclusivo (SIDIS). Nei decenni passati queste misure hanno fornito preziose informazioni sulla struttura adronica, tuttavia alcune domande fondamentali, tra cui l’emergere della massa e dello spin adronici dai costituenti elementari, sono ancora senza risposta. Una nuova generazione di esperimenti, come ePIC a EIC e AMBER al CERN, e stata proposta per fare luce sui fenomeni ancora sconosciuti. Il fondamento dei processi SIDIS e la rivelazione degli adroni nello stato finale e la loro identificazione ad alto momento (p ≳ 20 GeV/c) e cruciale; in questo range di momenti, la tecnica piu efficace per identificare gli adroni e rappresentata dai rivelatori Ring Imaging Cherenkov, detti RICH. La tecnologia RICH, basata sull’emissione di luce Cherenkov da parte di particelle che viaggiano a velocita superluminale in un mezzo adatto, normalmente richiede la rivelazione di fotoni su una grande area sensibile. I rivelatori di fotoni a gas rappresentano una soluzione ben consolidata e relativamente economica per coprire grandi superfici; inoltre possono essere utilizzati in presenza di campi magnetici. Recentemente, lo sviluppo della tecnologia Micro-Pattern Gaseous Detectors (MPGD) ha migliorato le performance dei rivelatori a gas per quanto riguarda la velocita e la riduzione del flusso di ioni sul fotocatodo. Il progetto presentato in questa tesi ha lo scopo di esportare la tecnologia di rivelazione di fotoni, basata su MPGD, sviluppata per il RICH-1 di COMPASS a una nuova generazione di esperimenti. Il grande numero e l’alto rate di dati previsto agli esperimenti futuri suggeriscono l’uso di un sistema di acquisizione non triggerato; tuttavia l’ettronica di front-end attualmente in uso nei rivelatori di fotoni a MPGD di COMPASS (APV25) puo essere utilizzata solo in modalita triggerata. Un candidato per sostituire l’APV25 e il VMM, un ASIC digitale a 64 canali sviluppato come front-end per MPGD. Un prototipo di rivelatore, con le stesse caratteristiche dei rivelatori a MPGD di COMPASS e stato costruito e testato con un’elettronica dalla risposta nota e con il VMM, per confermare il funzionamento di quest’ultimo. I test sono stati fatti sia con una sorgente di raggi X che con una di fotoni UV, che imita i fotoni Cherenkov. Le due elettroniche hanno dato risposte compatibili con entrambe le sorgenti, eterminando l’assenza di ostacoli all’uso del VMM per il readout di rivelatori di fotoni con tecnologia MPGD. Un’ulteriore limitazione dei rivelatori di fotoni con tecnologia MPGD e la fragilita dei fotocatodi a ioduro di cesio (CsI): un’importante riduzione di efficienza quantica si osserva a causa del bombardamento di ioni. In un rivelatore a gas la principale sorgente di ioni e il fenomeno di moltiplica della carica, pertanto ambienti ad alta radiazione pongono un limite all’uso del CsI come fotocatodo. Questa tesi presenta lo studio di un nuovo materiale fotoconvertitore, la polvere di nanodiamante idrogenato (H-ND): la sua efficienza quantica e confrontabile con quella del CsI ma e piu robusto contro il danno da radiazione. Nella tesi sono presentati sia la produzione del materiale sia la tecnica con cui esso viene depositato su un substrato. I risultati includono studi di efficienza quantica sia in vuoto che in gas, e uno studio del danno da radiazione. La tesi e conclusa dallo studio dell’accoppiamento dei H-ND con i rivelatori di fotoni a MPGD; i risultati indicano che le due tecnologie possono essere combinate per costruire un rivelatore di fotoni robusto alla radiazione.Hadron production in semi-inclusive measurements of deep-inelastic lepton nucleon scattering (SIDIS) is one of the most powerful tools to investigate the hadron structure. Despite the brilliant results that it has given in the past decades, some fundamental questions, like the emergence of hadron mass and spin from the hadron constituents remain unanswered. A new generation of experiments, like ePIC at the EIC and AMBER at CERN, is being planned to shed light on the phenomena that are still unknown. The core of SIDIS experiments is the measurement of the hadrons in the final state and their identification at high momenta (p ≳ 20 GeV/c) is crucial; in this momentum range, Ring Imaging Cherenkov Detectors (RICH) are the most effective way to address particle identification. RICH technology, based on the Cherenkov light emission of particles faster than light in a suitable medium, generally requires the detection of photons on a wide detection area. Gaseous Photon detectors represent a well established, cost-effective way to cover large areas; moreover they can be operated in the presence of a magnetic field. Recently, the development of the MPGD technology has improved the performance of gaseous photon detectors in terms of speed and reduction of the ion backflow at the photocathode. The R&D project presented in this thesis has the goal to export the MPGD-based photon detection technology developed for COMPASS RICH-1 to a future generation of experiments. The large amount of data and the high data rate foreseen at the future experiments suggest the use of a triggerless Data Acquisition (DAQ) system, however the front-end electronics used in COMPASS MPGD-based photon detector (APV25) can operate only in trigger mode. A candidate to substitute the APV25 is the VMM, a 64 channels, digital ASIC developed for MPGDs. A prototype chamber, with the same characteristics as COMPASS MPGD-based photon detectors has been built and tested both with a known front-end electronics and with the VMM to confirm the reliability of the latter. Tests were performed using an X-rays and a UV light source to mock Cherenkov photons. The two electronics gave comparable results with both photon sources, finding no obstacles to the use of VMM for the readout of MPGD-based Photon Detectors. Another limitation of the MPGD-based Photon Detectors is the fragility of the photocathodes, coated with (CsI): a severe decrease in quantum efficiency is observed following ion bombardment. In a gaseous detector the main source of ions is the avalanche process, so high radiation environments pose a limitation to the use of CsI based photocathodes. The thesis presents the study of a novel photoconverting material, hydrogenated nanodiamond (H-ND): its quantum efficiency is comparable with the one of CsI but it is more robust against radiation damage. In the thesis the production of the material is presented, as well as the spraying technique used to coat substrates. Presented results include studies of quantum efficiency, both in vacuum and in gas mixtures, and a study of radiation damage. The thesis is concluded by the study of the coupling of H-ND with COMPASS type Photon Detectors; results indicate that the two technologies can be combined for a more robust MPGD-based Photon Detetctor

    LHCb RICH: Technical Design Report

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