CERN has been building a transportable RFQ for use in the examination of art masterpieces based mainly on the PIXE (Proton Induced X-ray Emission) technique with an extracted beam. This new PIXE-RFQ ...accelerator is very compact, only one meter in length with a power consumption of less than 6 kVA for a beam energy of 2 MeV and an average current of 5 nA. The PIXE-RFQ will be used for the MACHINA (Movable Accelerator for Cultural Heritage In-situ Non-destructive Analysis) project developed jointly by CERN and INFN. This paper will present the detailed design and performances of the PIXE-RFQ as well as the fabrication technologies used and the current status of the project. The beam size and the peak current/duty cycle of the RFQ have been optimised for the Ion Beam Analysis (IBA) of artwork objects.
Over the years, transportable instrumentation for cultural heritage (CH) in situ measurements has noticeably widespread, due to logistic, economical and safety reasons. Ion beam analysis, a powerful ...set of analytical techniques, of great importance for CH, is instead carried out by using fixed instrumentation. To overcome this limit, the Italian national Institute of Nuclear Physics (INFN), CERN (European Centre for Nuclear Research) and the Opificio delle Pietre Dure (OPD), started MACHINA, the “Movable Accelerator for CH In-situ Non-destructive Analysis: the new generation of accelerators for art” to build a transportable accelerator, compact, with strongly reduced weight, absorbed power and cost. MACHINA will be installed at the OPD and dedicated to CH. It will be moved to major conservation centres and museums, when needed. The INFN-CERN proposal, approved in December 2017, became operative in February 2018. 2018 was dedicated to the acquisition of material/instrumentations, to set up both a dummy accelerator (to test the vacuum system) and a vacuum chamber (to test the source). Due to COVID, in 2020 and 2021 the experimental work was slowed down, but we kept developing the control electronics/software and built the second-generation supporting structure. The HF-RFQ power supplies were integrated in October 2021. At the rise of 2022, after conditioning the cavities, we tested the system and in March 2022 we got the first extracted 2-MeV proton beam. In this paper, we present the structure of the MACHINA system, the approach followed and the main solutions adopted, with a special focus on the control system, and finally the first experimental results.
The ATLAS Muon Trigger "Slice" Sidoti, A.; Bellomo, M.; Biglietti, M. ...
IEEE transactions on nuclear science,
02/2008, Letnik:
55, Številka:
1
Journal Article
Recenzirano
The ATLAS experiment at the Large Hadron Collider (LHC) will face the challenge of selecting interesting candidate events in proton-proton collisions at 14 TeV center of mass energy, while rejecting ...the enormous number of background events. The trigger system architecture is organized in three levels. From a bunch crossing rate of 40 MHz, the First Level trigger, hardware implemented, will reduce this rate to around ~75 kHz. Then the software based High Level Trigger (HLT), composed by the Second Level Trigger and the Event Filter reduces the rate to 200 Hz. In this paper, we will present the implementation of the muon trigger ldquoslice,rdquo signal efficiencies, background rejection rates, and system performances (execution time, memory consumption, etc.) for online muon selection based on Monte Carlo simulations and results obtained on real events collected during cosmic data taking runs.
Aria is a plant hosting a Formula omitted cryogenic isotopic distillation column, the tallest ever built, which is being installed in a mine shaft at Carbosulcis S.p.A., Nuraxi-Figus (SU), Italy. ...Aria is one of the pillars of the argon dark-matter search experimental program, lead by the Global Argon Dark Matter Collaboration. It was designed to reduce the isotopic abundance of Formula omitted in argon extracted from underground sources, called Underground Argon (UAr), which is used for dark-matter searches. Indeed, Formula omitted is a Formula omitted-emitter of cosmogenic origin, whose activity poses background and pile-up concerns in the detectors. In this paper, we discuss the requirements, design, construction, tests, and projected performance of the plant for the isotopic cryogenic distillation of argon. We also present the successful results of the isotopic cryogenic distillation of nitrogen with a prototype plant.
The Atlas Trigger System has been designed to reduce the LHC interaction rate of about 1 GHz to the foreseen storage rate of about 100 Hz. Three trigger levels are applied in order to fulfill such a ...requirement. A detailed simulation of the ATLAS experiment including the hardware components and the logic of the Level-1 Muon trigger in the barrel of the muon spectrometer has been performed. This simulation has been used not only to evaluate the performances of the system but also to optimize the trigger logic design. In the barrel of the muon spectrometer the trigger will be given by means of resistive plate chambers (RPCs) working in avalanche mode. Before being mounted on the experiment, accurate quality tests with cosmic rays are carried out on each RPC chamber using the test station facility of the INFN and University laboratory of Napoli. All working parameters are measured and the uniformity of the efficiency on the whole RPC surface is required. A summary of the Napoli cosmic rays tests, together with a brief description of the Atlas Trigger, in particular of the Level-1 Muon Trigger in the barrel, and the results of the trigger simulation will be given.
The ATLAS Level-1 and Level-2 trigger Falciano, Speranza
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/1996, Letnik:
384, Številka:
1
Journal Article
Recenzirano
The trigger system of the ATLAS experiment is organized as a multilevel architecture where the event selection is performed in three steps. The first level trigger, based on coarse calorimeter and ...muon detector information, is designed to accept data at the LHC bunch crossing rate of 40 MHz with a maximum output rate of 100 kHz. It also gives pointers to detector regions where to find tracks and energy clusters, thus guiding the Level-2 algorithms. Data from events accepted at Level-1 are stored in digital buffers and held over the Level-2 trigger latency. A second level selection is achieved by processing and combining full granularity calorimeter, muon and inner detector information to reduce the trigger rate to ∼1 kHz. The final selection of events is based on the full data sample to perform a complete event reconstruction. This step reduces the trigger rate by a further factor of 100. This paper describes the Level-1 and Level-2 triggers in terms of hardware implementation, algorithms and trigger strategies with particular emphasis on B physics.
We present the design of the first level muon trigger in the central toroid of the ATLAS experiment at the Large Hadron Collider (LHC). A trigger is foreseen based on fast, finely segmented gaseous ...detectors, Resistive Plate Chambers (RPC), to unambiguously identify the interaction bunch crossing. We describe the detectors and the logic scheme of the trigger.
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