163 research outputs found
miniLB: A Performance Portability Study of Lattice-Boltzmann Simulations
No full textThe Lattice Boltzmann Method (LBM) is a computational technique of Computational Fluid Dynamics (CFD) that has gained popularity due to its high parallelism and ability to handle complex geometries with minimal effort. Although LBM frameworks are increasingly important in various industries and research fields, their complexity makes them difficult to modify and can lead to suboptimal performance. This paper presents miniLB, the first, to the best of our knowledge, SYCL-based LBM mini-app. miniLB addresses the need for a performance-portable LBM proxy app capable of abstracting complex fluid dynamics simulations across heterogeneous computing systems. We analyze SYCL semantics for performance portability and evaluate miniLB on multiple GPU architectures using various SYCL implementations. Our results, compared against a manually-tuned FORTRAN version, demonstrate effectiveness of miniLB in assessing LBM performance across diverse hardware, offering valuable insights for optimizing large-scale LBM frameworks in modern computing environments
Cherenkov light imaging tests with state-of-the-art solid state photon counter for the CLAS12 RICH detector
No full textA large area ring-imaging Cherenkov detector will be operated for hadron identification in the 3GeV/c to 8GeV/c momentum range at the CLAS12 experiment at the upgraded continuous electron beam accelerator facility of Jefferson Lab. The detector, consisting of aerogel radiator, composite mirrors and photon counters, will be built with a hybrid optics design to allow the detection of Cherenkov light for both forward and large angle hadron tracks. The active area has to be densely packed and highly segmented, covering about 1m2 with pixels of 6mm2, and to allow a time resolution of 1. ns. A technology that can offer a cost-effective solution and low material budget could be Silicon Photomultipliers (SiPM) thanks to their high gain at low bias voltage, fast timing, good single-photoelectron resolution and insensitivity to magnetic fields. An investigation is ongoing on samples of 3×3mm2 SiPM of different micro-cell size to assess the single photon detection capability in the presence of high dark count rate due to thermal generation effects, after-pulses or optical cross-talk and to study the response to the moderate radiation damage expected at CLAS12. In this work, a brief review of the latest and most interesting results from these studies will be shown
Design, performance and perspective of the NA62-RICH
No full textNA62 is an experiment designed to measure the branching fraction of the ultra-rare decay of the positively charged kaon into a pion and a neutrino-antineutrino pair. The specialties of its Ring Imaging Cherenkov detector (RICH) are the muon-pion separation, the sub-nanosecond timing and the participation in the lowest level trigger of the experiment. These characteristics made the NA62-RICH crucial for the physics data taking that run in the three-year period 2016–2018. Two aspects are currently under consideration to increase the impact of RICH in the broad NA62 physics program: a better time resolution to cope with higher intensity beam and the online extraction of high level features to be used in the trigger logic. This paper describes the RICH detector and presents its possible upgrades
Aerogel mass production for the CLAS12 RICH: Novel characterization methods and optical performance
No full textA large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification
capabilities in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the Jefferson Lab
upgraded 12 GeV continuous electron beam accelerator facility. The adopted solution foresees a novel hybrid
optics design based on an aerogel radiator, composite mirrors and densely-packed and highly-segmented
photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections
(large angle tracks). The status of the aerogel mass-production and the assessment studies of the aerogel optical
performance are here reported
Progress report on the online processing upgrade at the NA62 experiment
No full textA new FPGA-based low-level trigger processor has been installed at the NA62 experiment. It is intended to extend the features of its predecessor due to a faster interconnection technology and additional logic resources available on the new platform. With the aim of improving trigger selectivity and exploring new architectures for complex trigger computation, a GPU system has been developed and a neural network on FPGA is in progress. They both process data streams from the ring imaging Cherenkov detector of the experiment to extract in real time high level features for the trigger logic. Description of the systems, latest developments and design flows are reported in this paper
Progress report on the online processing upgrade at the NA62 experiment
No full textA new FPGA-based low-level trigger processor has been installed at the NA62 experiment. It is intended to extend the features of its predecessor due to a faster interconnection technology and additional logic resources available on the new platform. With the aim of improving trigger selectivity and exploring new architectures for complex trigger computation, a GPU system has been developed and a neural network on FPGA is in progress. They both process data streams from the ring imaging Cherenkov detector of the experiment to extract in real time high level features for the trigger logic. Description of the systems, latest developments and design flows are reported in this paper
Time and DOI Resolution Measurements of Minidetectors for a PET-TOF Prostate Probe
No full textProstate cancer (PC) is the most common disease in western countries and a leading cause of cancer death. Powerful techniques and instruments for diagnosis such as CT, MRI, PET/SPECT suffer from limited spatial resolution, sensitivity and/or specificity. Dedicated detectors and techniques are needed. For this reason a new INFN research project (TOPEM) started with the goal of designing, building and testing an endorectal PET-TOF probe compatible with MRI, to be used in coincidence with an external dedicated detector and/or a standard PET ring. Multimodality imaging can play a significant role, merging anatomical and functional details coming from simultaneous PET and MRI (and MRS) scans. Good spatial resolution and Depth Of Interaction (DOI) resolution are needed in order to guarantee high performance in image reconstruction. Here the main focus is a characterization of the elementary detector unit, in terms of energy, timing and DOI resolution. Exploiting the TOF capability allows an increase in the SNR/NECR and also permits elimination of bladder background. Silicon Photo Multipliers (SiPM) are the obvious choice as photodetectors to be coupled with small finger scintillators. Good preliminary results have been obtained both on DOI and Timing resolutions. © 2011 IEEE
Light detection system and time resolution of the NA62 RICH
No full textA large RICH detector is used in NA62 to suppress the muon contamination in the charged pion sample by a factor of 100 in the momentum range between 15 and 35 GeV/c. Cherenkov light is collected by 1952 photomultipliers placed at the upstream end. In this paper the characterization of the photomultipliers and the dedicated Frontend and Data Acquisition electronics are described, the time resolution and the light detection efficiency measurement are presented
The large-area hybrid-optics RICH detector for the CLAS12 spectrometer
No full textA large area imaging Cherenkov detector is under construction to provide hadron identification in the momentum range between 3 and 8 GeV/c for the CLAS12 exeperiment at the new 12 GeV electron beam of the Jefferson Laboratory (JLab). The detector adopts a hybrid optics solution with aerogel radiator, light planar and spherical mirrors and highly-segmented photon detectors. Cherenkov photons will be imaged either directly (for forward tracks) or after two mirror reflections (large angle tracks). The status of the detector construction is here reported
TOPEM: A multimodality probe (PET TOF, MRI, and MRS) for diagnosis and follow up of prostate cancer
No full textMultimodality imaging plays a significant role on specific diagnosis of prostate cancer. An endorectal PET-TOF MRI probe, designed here, allows for improved SNR and NECR with respect to standard imagers, providing better functional diagnosis of prostate diseases. © 2010 IEEE
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