Search

The Mu2e experiment at the Fermilab Muon Campus will search for the coherent neutrinoless conversion of a muon into an electron in the field of an aluminum nucleus with a sensitivity improvement by a factor of 10 000 over existing limits. Such a charged lepton flavor-violating reaction probes new physics at a scale unavailable with direct searches at either present or planned high-energy colliders. The Mu2e Trigger and Data Acquisition (TDAQ) system exploits otsdaq as its online Data Acquisition System (DAQ) solution. Developed at Fermilab, otsdaq integrates both the artdaq DAQ and the art analysis frameworks for event transfer, filtering, and processing. otsdaq is an online DAQ software suite with a focus on flexibility and scalability and provides a multi-user, web-based, interface accessible through a web browser. The read out controllers (ROCs) stream out zero-suppressed data continuously from the detector subsystems to the data transfer controllers (DTCs). The data stream is then read over the peripheral component interconnect express (PCIe) bus to a software filter algorithm that selects events which are combined with the data flux coming from a cosmic-ray veto (CRV) system. The detector control system (DCS) has been developed using the experimental physics and industrial control system (EPICS) open source platform for monitoring, controlling, alarming, and archiving. The DCS has been integrated into otsdaq. A prototype of the TDAQ system and the DCS has been built at Fermilab’s Feynman Computing Center. In this article, we report on the progress of the integration of this prototype in the online otsdaq software. [ABSTRACT FROM AUTHOR]

J-PARC E16 is an experiment to examine the origin of hadron mass through a systematic measurement of spectral changes of vector mesons in nuclei. The measurement of $e^{+}e^{-}$ pairs from the decay of vector mesons will provide the information of the partial restoration of the chiral symmetry in a normal nuclear density. To resolve a pulse pile-up and achieve good discrimination of $e^{+}$ and $e^{-}$ from the background of a reaction rate of an order of 10 MHz, the data acquisition (DAQ) system uses waveform sampling chips of APV25 and DRS4. The trigger rate and data rate are expected to be 1 kHz and 120–330 MiB/s, respectively. The DAQ system for readout of APV25 and DRS4 were developed, where events were synchronized by common trigger and tag data. The first commissioning in beam, called Run-0a, was performed in June 2020 with about 1/4 of the designed setup. The DAQ worked with a trigger rate of 300 Hz in the Run-0a and the main bottleneck was a large data size of APV25. Further optimization of the DAQ system will improve the performance. [ABSTRACT FROM AUTHOR]

The CMS experiment at the LHC selects events with a two-level trigger system, the Level-1 (L1) trigger, and the high-level trigger (HLT). The HLT reduces the rate from 100 to about 1 kHz and has access to the full detector readout and runs a streamlined version of the offline event reconstruction. During LHC Run-2, the peak instantaneous luminosity reached values up to $2.0\times 10^{34}$ cm−2s−1, posing a challenge to the online event selection. An overview of the HLT system at CMS, the online physics object reconstruction, and the main triggers using those physics objects in 2016–2018 proton collision data-taking period is presented. The performance of a representative set of physics triggers is also discussed. [ABSTRACT FROM AUTHOR]

A field programmable gate array (FPGA)-based online trigger system has been developed for the COherent Muon To Electron Transition (COMET) Phase-I experiment, which searches for muon-to-electron conversion as a signature of New Physics beyond the Standard Model. A drift chamber and trigger counters are devised to detect a mono-energetic electron from the conversion process in a 1-T solenoidal magnetic field. A highly intense muon source enables reaching unprecedented experimental sensitivity, however, it also generates undesirable background particles which increase the trigger rate to a much higher level than the capability of the data acquisition (DAQ) system. By using hit information from the drift chamber in addition to the trigger counter, the newly proposed online trigger system efficiently suppresses the background trigger rate while keeping the signal-event acceptance large. A characteristic of this system is the utilization of machine learning (ML) techniques for optimizing lookup tables (LUTs) implemented in hardware. Simulation studies show that the signal-event acceptance of the online trigger is 96% while the background trigger rate is reduced from 91 to 13 kHz. The global trigger system and trigger electronics that construct a distributed trigger architecture were built. The total trigger latency was estimated to be $3.2~\mathrm {\mu s}$. The trigger system test was carried out by using a part of the drift-chamber readout region. [ABSTRACT FROM AUTHOR]

The Belle II experiment at the SuperKEKB collider at KEK, Tsukuba, Japan has successfully started taking data with the full detector in March 2019. Belle II is a luminosity frontier experiment of the new generation to search for physics beyond the Standard Model of elementary particles, from precision measurements of a huge number of $B$ and charm mesons and tau leptons. To read out the events at a high rate from the seven subdetectors of Belle II, we adopt a highly unified readout system, including a unified trigger-timing distribution system (TTD), a unified high-speed data link system (Belle2link), and a common backend system to receive Belle2link data. Each subdetector frontend readout system has a field-programmable gate array (FPGA) in which unified firmware components of the TTD receiver and Belle2link transmitter are embedded. The system is designed for data taking at a trigger rate up to 30 kHz with a dead-time fraction of about 1% in the frontend readout system. The trigger rate is still much lower than our design. However, the background level is already high because of the initial vacuum condition and other accelerator parameters, and it is the most limiting factor of the accelerator and detector operation. Hence, the occupancy and radiation effects to the frontend electronics are rather severe, and they cause various kinds of instabilities. We present the performance of the system, including the achieved trigger rate, dead-time fraction, and stability, and discuss the experience gained during the operation. [ABSTRACT FROM AUTHOR]

The large Hadron collider (LHC) is expected to increase its center-of-mass energy from 13 to 14 TeV for Run 3 scheduled from 2022 to 2024. After Run 3, upgrades for the high-luminosity-LHC (HL-LHC) program are planned and the operation will start in 2027, increasing the instantaneous luminosity to 5.0–7.5 times its nominal luminosity. Continuous upgrades of the ATLAS trigger system are planned to cope with the high event rate and to keep the physics acceptance. During the long shutdown period before Run 3, new detectors will be installed to improve the trigger performance. A new trigger logic, combining information from detectors located outside of the magnetic field and new detectors installed inside the magnetic field, will be introduced for Run 3 to reduce the trigger rate. In order to handle data from the various detectors, a new trigger processor board has been developed and the design is presented. During the upgrade for HL-LHC, the trigger and readout systems of the first level hardware-based part are planned to be upgraded. Full-granularity information will be transferred to the trigger processor board which enables more OFF-line like track reconstruction in the hardware-based system. To handle the full-granularity information and perform the hardware-based track reconstruction, the trigger processor board will be equipped with a field programmable gate array (FPGA) with hundreds of transceivers and a large memory. Expected performance for the hardware-based endcap muon trigger in Run 3 and HL-LHC will also be presented. [ABSTRACT FROM AUTHOR]

The Mu3e experiment aims to find or exclude the lepton flavor violating decay μ+ → e+e−e+$ with a sensitivity of one in 1016 muon decays. The first phase of the experiment is currently under construction at the Paul Scherrer Institute (PSI, Switzerland), where beams with up to 108 muons per second are available. The detector will consist of an ultra-thin pixel tracker made from High-Voltage Monolithic Active Pixel Sensors (HV-MAPS), complemented by scintillating tiles and fibers for precise timing measurements. The experiment produces about 100Gbit/s of zero-suppressed data, which are transported to a filter farm using a network of field programmable gate arrays (FPGAs) and fast optical links. On the filter farm, tracks and three-particle vertices are reconstructed using highly parallel algorithms running on graphics processing units, leading to a reduction of the data to 100 Mbyte/s for mass storage and offline analysis. This article introduces the system design and hardware implementation of the Mu3e data acquisition and filter farm. [ABSTRACT FROM AUTHOR]

The design and performance of a new front-end acquisition system is presented in this paper. It was developed to be used with muon array with resistive plate chamber (RPCs) for tagging air showers (MARTA’s) RPC detectors that measure the muonic component of cosmic ray air showers. The system is hybrid and capable of counting active channels and performing a charge measurement. It is low power (1.43 W per 64 channels), compact ($21.6 \times 14.4\,\,\mathrm {cm^{2}}$ per 64 channels), stable, and reliable to comply with the strict demands of field operation associated with experiments that measure air showers. The front-end is based on an application-specified integrated circuit [Multi Anode Read-Out Chip (MAROC)] with 64 input channels, which is responsible for the digitization of the RPC signals. While a simple threshold measurement is applied after a fast shaper to count particles, the charge measurement is performed by an analog to digital converter that reads the peak of a slow shaper. An field-programmable gate array is responsible for control of all the digital part which includes storing the MAROC outputs and sending them to a Central Unit [via low voltage differential signal (LVDS)] or PC (via USB). Both the count and charge measurement performance are assessed. The threshold efficiency curve is measured for different temperatures. For all the conditions tested, the efficiency is 100% for charges higher than 52 fC. The overall efficiency to detect muons is studied by placing an RPC between a hodoscope and comparing the efficiency of the front-end with another established data acquisition system. The efficiency results are consistent within the statistical uncertainties of the measurements showing that the MARTA front-end does not introduce unwanted inefficiencies in the setup. The charge measurement is tested in the laboratory using a signal generator. Different shaping conditions and input charges are used to study the waveform of the slow shaper. A linear dependence between input charge and the value measured by the MAROC was found and taken as the calibration curve for the particular channel tested. [ABSTRACT FROM AUTHOR]

The Muon g-2 experiment at Fermilab will measure the muon anomalous magnetic moment $a=(g-2)/2$ to an unprecedented precision of 0.14 parts per million (ppm). To this aim, a calibration system made by a laser source and light distribution will provide short light pulses directly into each crystal of the 24 calorimeters to measure energy and arrival time of the decay positrons. Each calorimeter is composed of a 6\times 9$ matrix of PbF_{2} crystals where each crystal is read by a silicon photomultiplier. Continuous monitoring and state-of-the-art calibration are required in order to control the detector response. The calibration light pulses are monitored, both at the laser output (source monitor) and at the end of the distribution system (local monitor), before delivery to the calorimeters. For example, the light pulses are read by specific photodetectors, whose signals are digitized by electronics designed to match the experimental requirements. All readout electronics boards are hosted in a crate where the controller manages the complete data collection, operates as an event builder and transfers data to the online farm system through a gigabit Ethernet connection. This data acquisition (DAQ) system is designed around a custom protocol and hardware to achieve high data transfer rate and event-building capability without software overhead. In this paper, after a general outline of this DAQ system, we describe in detail the main features of controller. [ABSTRACT FROM AUTHOR]

The KOTO experiment at J-PARC, Japan, aims to observe the rare neutral kaon decay mode KL\rightarrow \pi ^{0}\nu \bar {\nu } . After the first experimental run in May 2013 at a 24-kW beam power, the KOTO data acquisition (DAQ) system was upgraded in 2015 to provide efficient and reliable data collection at higher beam intensities. Lossless data compression in the analog-to-digital converter modules was implemented to reduce the size of data packets, resulting in a threefold increase in data collection rate. A new software trigger on a 47-node cluster was designed to use Infiniband hardware with message passing interface protocol to establish a mesh network inside the computer clusters for parallel data processing. The upgrade to the KOTO DAQ system was commissioned in 2015 and successfully collected data with a beam intensity of up to 42 kW. In preparation for increasing beam intensities in future runs, the hardware trigger upgrades using the reconfigurable clustering element platform technology are under development. [ABSTRACT FROM AUTHOR]

The NA62 experiment refid="ref1"/ at CERN SPS (Super Proton Synchrotron) accelerator aims at studying Kaon decays with high precision. The high resolution Liquid Krypton (LKr) calorimeter, built for the NA48 refid="ref2"/ experiment, is a crucial part of the photon-veto system; to cope with the demanding NA62 requirements, its back-end electronics had to be completely renewed. The new readout system is based on the Calorimeter REAdout Module (CREAM) refid="ref3"/, a 6U VME board whose design and production was sub-contracted to CAEN refid="ref4"/, with CERN NA62 group continuously supervising the development and production phase. The first version of the board was delivered by the manufacturer in March 2013 and, as of June 2014, the full board production is ongoing. In addition to describing the CREAM board, all aspects of the new LKr readout system, including its integration within the NA62 TDAQ scheme, will be treated. [ABSTRACT FROM AUTHOR]

Belle II, an experiment designed to search for physics beyond the standard model in the decay of B mesons, will soon start operation at the Super KEKB e^ + e^ - collider. The trigger rate is expected to be 30 kHz with a margin of 10 kHz, and the raw data rate will exceed 30 GB/s. Since the system will be unable to record all data on its storage system, online reduction is required. We have developed a three-level event building system using inexpensive switches and software for traffic smoothing, enabling online event processing at a reasonable cost. The data will be recorded on the storage system about 3 GB/s after rate reduction. This paper describes the architecture and the verification result in actual beam tests. [ABSTRACT FROM PUBLISHER]

High-energy physics experiments at the high-intensity frontier place ever-greater demands on detectors, and in particular on tracking devices. In order to compare the performance of many possible small-size tracking prototypes, a high-resolution cosmic ray tracker may be used as an external track reference. We have constructed a telescope by assembling four spare ladders of the external layers of the Silicon Vertex Tracker of the BaBar experiment. This test facility, operating at INFN Sezione di Pisa, provides the detector under test with an external track with an intrinsic resolution of 15–30 ~\mu\m. The DAQ originally used in the BaBar experiment was replaced by custom-designed boards coupled with an acquisition front-end personal computer through commercial field-programmable gate array evaluation boards. We show that the facility is operative, and we present the performance in terms of tracking resolution and efficiency. A first device has been characterized, and some plots from the analysis demonstrating the telescope performance are shown. [ABSTRACT FROM PUBLISHER]

The upcoming Belle II experiment is designed to work at a luminosity of 8\times 10^35 cm^-2s^-1, 40 times higher than its predecessor. The pixel detector of Belle II with its \sim8 million channels will deliver ten times more data than all other sub-detectors together. A data rate of 22 Gbytes/s is expected for a trigger rate of 30 kHz and an estimated pixel detector occupancy of 3%, which is by far exceeding the specifications of the Belle II event builder system. Therefore a realtime data reduction of a factor > 30 is needed. [ABSTRACT FROM AUTHOR]

In order to explore new physics in B-meson decays we plan to upgrade the KEK B-factory to a luminosity of 5 × 1035 cm-2s-1. In parallel we are developing a new pipelined data acquisition system for the Belle detector to cope with higher trigger rates of up to 30 kHz and severe background conditions. In order to reduce development and maintenance costs, we have adopted a modular design for these new readout electronics. The chosen architecture consists of a common readout platform, upon which are mounted subdetector specific parts, customized to meet the readout requirements of each sub detector component. As an example of this new architecture, we present in this paper the design of drift chamber electronics. The drift chamber readout utilizes the AMT-3 time-to-digital converter chip, originally developed for the ATLAS experiment, which satisfies the performance requirement for current and future Belle drift chamber readout. A data transfer performance test with emulation modules, mounted on the common platform, shows that the new readout electronics works well at a more than 30 kHz input trigger rate. [ABSTRACT FROM AUTHOR]