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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 increase in atmospheric CO2 concentrations has initiated research into carbon sequestration methods. One possibility is to store CO2 in subsurface porous reservoirs. Monitoring the injected CO2 plume is vital because escaping CO2 poses health and environmental risks. Typically, seismic reflection methods are used to determine the change in density due to the replacement of brine by CO2 in the reservoir but this is expensive and not continuous. A potential alternative is to use cosmic muon tomography to measure density changes in the reservoir as a function of time. This paper describes the development of a muon detector that will be capable of being deployed in boreholes. The detector will be designed to have the required dimensions, an angular resolution of approximately 2°, and be mechanically robust. The prototype design is based on alternating layers of scintillating rods, which can provide 4-D reconstruction of the overburden to detect small changes in density at depths up to approximately 2 km. Geant4, a Monte Carlo simulation code, is being used to develop models to guide the design of the physical configuration. Preliminary testing and measurements have been performed to validate the simulation predictions and optimize physical performance parameters. The simulated and preliminary experimental results are presented here. [ABSTRACT FROM AUTHOR]

We report on the design of a serializer ASIC to be used in the ATLAS forward muon detector for trigger data transmission. We discuss the performance of a prototype chip covering power dissipation, latency and stable operating line rate. Tests show that the serializer is capable of running at least at 5.76 Gbps with a bit error ratio below 1 \times 10^- 15, and a power consumption of 200 mW running at 4.8 Gbps. The latency between the start of loading 30 bits into the serializer to the transmission of the first bit from the serializer is measured to be about 6 ns. [ABSTRACT FROM AUTHOR]

The increase in center-of-mass energy and luminosity for Run-II of the Large Hadron Collider poses new challenges for the trigger systems of the experiments. To keep triggering with a similar performance as in Run-I, the CMS muon trigger is currently being upgraded. The new algorithms will provide higher resolution, especially for the muon transverse momentum and will make use of isolation criteria that combine calorimeter with muon information already in the level-1 trigger. The demands of the new algorithms can only be met by upgrading the level-1 trigger system to new powerful FPGAs with high bandwidth I/O. The processing boards will be based on the new \mu TCA standard. We report on the planned algorithms for the upgraded Global Muon Trigger (\muGMT) which sorts and removes duplicates from boundaries of the muon trigger sub-systems. Furthermore, it determines how isolated the muon candidates are based on calorimetric energy deposits. The \muGMT will be implemented using a processing board that features a large Xilinx Virtex 7 FPGA. Up to 72 optical links at 10 Gb/s will be used to receive muon candidates and energy sums from the calorimeter trigger. Muon candidates will be received directly from the sector processors of the upgraded trigger, absorbing the final sorting stage of each muon sub-system and thus minimizing the latency of the trigger. [ABSTRACT FROM PUBLISHER]

We present VMM1, the first prototype of a family of front-end ASICs designed for the ATLAS muon upgrade. The ASIC will operate with MICROMEGAS and TGC detectors, providing charge and timing measurements along with other features including sub-hysteresis discrimination, address of the first event in real time, and digital output per channel for Time-over-Threshold measurements. The shaper, designed via the concept of Delayed Dissipative Feedback (DDF), supports analog dynamic ranges in excess of 10\thinspace000. With a capacitance of 200 pF and a nominal peaking time of 25 ns, the ASIC offers resolution of charge and timing better than 1 fC and 1 ns, respectively, for input charges up to 2 pC. Designed in a commercial 130 nm technology it dissipates about 4.5 mW per channel. [ABSTRACT FROM PUBLISHER]

The resistive plate chambers (RPCs) muon trigger electronics of the Compact Muon Solenoid (CMS) detector performs a number of tasks: synchronization of detector signals, optical data transmission from the detector to the trigger electronics, pattern recognition, muons momentum measurement, selection of track candidates. For the diagnostic purposes, as well as for the calibration and real-time monitoring of the RPC detectors and electronic hardware, a set of flexible diagnostic modules was designed and implemented into the field programmable gate arrays on which the trigger electronics is based. These include: multichannel counters, timing histograms, test pulses generators, diagnostic readout and data spying ("snap-shots" of the data stream). Test results presented in this paper, including tests with Large Hadron Collider-like muon beam, illustrate the performance and the usefulness of these diagnostic modules [ABSTRACT FROM PUBLISHER]

ATLAS is a detector at CERN's Large Hadron Collider where bunches of protons in counter-rotating beams will cross every 25 ns producing, on average, about 25 collisions for a total interaction rate of 1 GHz. A three-level trigger system selects bunch crossings potentially containing interesting processes. The Level-1 trigger, implemented in electronics and firmware, makes an initial selection in under 2.5 mus with an output rate of less than 100 kHz. A key element of this is the core module of the Central Trigger Processor which combines trigger information from the calorimeter and muon trigger processors to make the final Level-1 accept decision in under 75 ns. The event-selection algorithm used by the core module is based on lists of selection criteria, i.e., trigger menus, and is implemented in fully programmable look-up tables and content-addressable memories. In addition to the event selection, the core module generates dead-time in order to limit the frequency of Level-1 accepts to a rate that the sub-detector front-end electronics can support. The core module further provides trigger-summary information to the Level-2 trigger and to the data acquisition system. The design of the core module is presented, and results from recent laboratory tests and from tests with the calorimeter and muon trigger processors connected to detectors in a particle beam are shown [ABSTRACT FROM PUBLISHER]

The Atlas muon spectrometer relies on Monitored Drift Tubes (MDTs) for track reconstruction in most regions. Expected count rates due to photons reach up to 1500 Hz/cm for the innermost MDTs. For a gas gain of 2middot104 this corresponds to an overall accumulated charge of up to 0.6 C/cm which the MDTs must be able to withstand in 10 years of LHC operation without a degradation in their performance. With the main MDT parameters and the design frozen and chamber production well under way the focus of present aging studies is on testing final Atlas chambers instead of using small, dedicated setups under very well controlled conditions as in the past. This paper summarizes the results of such a study performed at the CERN Gamma Irradiation Facility GIF, that aims to emulate LHC background conditions. One of the main goals was to evaluate the principle of gas recirculation and a prototype of the Atlas circulation system [ABSTRACT FROM PUBLISHER]

A cosmic ray measurement facility has been set up at Ludwig-Maximilians-University Munich (LMU) and is used at present to commission and calibrate Monitored Drift Tube (MDT) chambers for the muon spectrometer of the ATLAS experiment. Each of these chambers-produced in collaboration with the Max-Planck-Institut fuumlr Physik and the Joint Institute for Nuclear Research in Dubna-consists of 432 drift tubes with a diameter of 3 cm, which are arranged in 2times3 layers, and measures 3.8 mtimes2.2 mtimes0.5 m. At the LMU site, the MDT chambers are completed, equipped with their final front-end electronics and taken into operation for the first time. The gas leak rate of the chamber is determined and its high voltage stability is tested. The response of all drift tubes and its homogeneity across the chamber is measured in the Cosmic Ray Facility. Two MDT chambers which were precisely mapped with an X-Ray tomograph provide reference tracking for the enclosed third chamber which is to be calibrated. The sense wire positions are determined from a comparison of the drift time measurements with the reference tracks. The geometry of the tested chamber-the grid constants of the drift tubes in a layer, the distances and tilt angles of the layers-can then be derived from these positions. Alignment systems are used to monitor chamber movements at the micrometer level. In the ongoing series commissioning, a rate of one chamber per week has been achieved. The parameters describing the geometry of the MDT chambers are determined with a precision in the 10 mum range. The measurements with cosmic muons complement the chamber surveys performed during construction and will provide an important input for the calibration of the entire ATLAS muon spectrometer [ABSTRACT FROM PUBLISHER]

A readout method based on fast waveform digitalization is proposed which improves the performance of large multiwire proportional chambers (MWPCs) with delay-line readout. Atmospheric muon detection data are presented, obtained with a 1 mtimes1 m, 200 wire, MWPC and two plastic scintillators, having the same sensitive area, used for muon identification purposes. The performance of two alternative data acquisition configurations is compared: the standard one, based on analog constant fraction discriminators (CFDs), and one using 5 GS/s waveform digitizers in which a CFD-like analysis is performed offline. The latter is shown to provide better, and more uniform, space resolution, allowing to correct position-dependent rise-time variations across the detector. The new technique is applicable to low count-rate applications, such as muon attenuation measurements in large matter volumes [ABSTRACT FROM PUBLISHER]

We present a custom integrated circuit, named DIALOG (DIagnostic, time Adjustment and LOGics), which is a fundamental building block in the front-end architecture of the LHCb Muon detector. DIALOG is realized in IBM 0.25 mum technology, using radiation-hardening layout techniques. DIALOG integrates important tools for detector time alignment procedures and time alignment monitoring on the front-end system. In particular, it integrates 16 programmable delays, which can be regulated in steps of 1 ns. Other features, necessary for the Muon trigger operation and for a safe front-end monitoring are integrated into DIALOG. It generates the information, that will be used by the trigger, as a combination of its 16 inputs from the Amplifier-Shaper-Discriminator (ASD) chips, it generates the thresholds of the ASD, it monitors the rate of all its input channels. We describe the circuit architecture, its internal blocks and its main modes of operation. Measurements performed on final prototypes are also reported [ABSTRACT FROM PUBLISHER]