The inner tracking layers of all LHC experiments were designed and developed to cope with the environment of the present Large Hadron Collider (LHC). At the LHC Phase-II Upgrade foreseen for 2026, ...the particle densities and radiation levels will increase by roughly an order of magnitude compared to the present LHC conditions. Therefore, the inner tracking layers will need to be replaced. The new inner tracking layers, which will all be based on silicon detectors, must be significantly more radiation hard. Within the RD50 Collaboration, an extensive R&D program has been underway for more than a decade across experimental boundaries to develop silicon sensors with sufficient radiation tolerance for HL-LHC trackers. Critical areas of detectors R&D include HV CMOS sensors, detectors made in the 3D technology and Low Gain Avalanche Detectors (LGADs). We will present the state of the R&D in several silicon detector domains, in particular, 3D and LGAD detectors. We will also comment on the options for detector choices experiments beyond the LHC, using the FCC as an example.
Events reconstruction at 30 MHz for the LHCb upgrade Szumlak, T.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Letnik:
936
Journal Article
Recenzirano
The Large Hadron Collider (LHC) Run 2 data taking period is coming to its end this year (2018). With the upcoming Long Shutdown 2 that will last till the end of 2020 we enter the upgrade era for the ...LHC based experiments. The LHCb experiment is going for a major upgrade (called LHCb Upgrade I) that practically affects all hardware components of the experimental setup as well as the DAQ and trigger. The LHCb event reconstruction procedure needs to face the challenge of fulfilling extremely tight time constraints imposed by a fully software trigger system running at the frequency of 30 MHz what corresponds to the inelastic event rate. At the same time this real time system must ensure the high level of physics performance needed by the LHCb scientific programme. This challenge requires rethinking and optimizing the logic of the event reconstruction algorithms, exploiting to the best the detectors properties and adopting out-of-the-box innovative ideas.
Tracking system of the upgraded LHCb Obłąkowska-Mucha, A.; Szumlak, T.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Letnik:
824
Journal Article
Recenzirano
The upgrade of the LHCb experiment will run at an instantaneous luminosity up to 2×1033cm−2s−1 with a fully software based trigger, allowing us to read out the detector at a rate of 40MHz. For this ...purpose, the full tracking system will be newly developed: the vertex locator (VELO) will be replaced by a pixel-based detector providing an excellent track reconstruction with an efficiency of above 99%. Upstream of the magnet, a silicon micro-strip detector with a high granularity and an improved acceptance, called the Upstream Tracker (UT) will be placed. The tracking system downstream of the magnet will be replaced by the Scintillating Fibre tracker (SciFi), which will consist of 12 layers using 2.5m long scintillating fibres read out by silicon photo-multipliers.
Abstract
Currently, the most used methods of plastic scintillator (PS) manufacturing are cell casting and bulk polymerisation, extrusion, injection molding, whereas digital light processing (DLP) 3D ...printing technique has been recently introduced. For our research, we measured blue-emitting EJ-200, EJ-208, green-emitting EJ-260, EJ-262 cell cast and two types of blue-emitting DLP-printed PSs. The light output of the samples, with the same dimension of 10 mm × 10 mm × 10 mm, was compared. The light output of the samples, relative to the reference EJ-200 cell-cast scintillator, equals about 40–49 and 70–73% for two types of 3D-printed, and two green-emitting cell-casted PSs, respectively. Performance of the investigated scintillators is sufficient to use them in a plastic scintillation dosemeter operating in high fluence gamma radiation fields.
LHCb is a dedicated experiment to study New Physics in the decays of heavy hadrons at the Large Hadron Collider (LHC) at CERN. Heavy hadrons are identified through their flight distance in the Vertex ...Locator (VELO). The VELO comprises 42 modules made of two n+-on-n 300μm thick half-disc silicon sensors with R- and Φ-measuring micro-strips. In order to allow retracting the detector, the VELO is installed as two movable halves containing 21 modules each. The detectors are operated in a secondary vacuum and are cooled by a bi-phase CO2 cooling system. During data taking in LHC Run 1 the LHCb VELO has operated with an extremely high efficiency and excellent performance. The track finding efficiency is typically greater than 98%. An impact parameter resolution of less than 35μm is achieved for particles with transverse momentum greater than 1GeV/c. An overview of all important performance parameters will be given. The VELO sensors have received a large and non-uniform radiation dose of up to 1.2×10141MeV neutron equivalent cm−2 during the first LHC run. Silicon type-inversion has been observed in regions close to the interaction point. The preparations for LHC Run 2 are well under way and the VELO has already recorded tracks from injection line tests. The current status and plans for new operational procedures addressing the non-uniform radiation damage are shortly discussed.
The LHCb Vertex Locator (VELO) is a silicon strip semiconductor detector operating at just 8mm distance to the LHC beams. Its 172,000 strips are read at a frequency of 1.1 MHz and processed by ...off-detector FPGAs followed by a PC cluster that reduces the event rate to about 10 kHz. During the second run of the LHC, which lasts from 2015 until 2018, the detector performance will undergo continued change due to radiation damage effects. This necessitates a detailed monitoring of the data quality to avoid adverse effects on the physics analysis performance. The VELO monitoring infrastructure has been re-designed compared to the first run of the LHC when it was based on manual checks. The new system is based around an automatic analysis framework, which monitors the performance of new data as well as long-term trends and using dedicated algorithms flags issues whenever they arise. The new analysis framework then analyses the plots that are produced by these algorithms. One of its tasks is to perform custom comparisons between the newly processed data and that from reference runs. The most-likely scenario in which this analysis would identify an issue is the parameters of the readout electronics no longer being optimal and requiring retuning. The data of the monitoring plots can be reduced further, e.g. by evaluating averages, and these quantities are input to long-term trending. This is used to detect slow variation of quantities, which are not detectable by the comparison of two nearby runs. Such gradual change is what is expected due to radiation damage effects. It is essential to detect these changes early such that measures can be taken, e.g. adjustments of the operating voltage, to prevent any impact on the quality of high-level quantities and thus on physics analyses. The plots as well as the analysis results and trends are made available through graphical user interfaces (GUIs). These GUIs are dynamically configured by a single configuration that determines the choice and arrangement of plots and trends and ensures a common look and feel.
Vertex locator (VELO) is a silicon microstrip detector situated around the interaction point in the large Hadron Collider beauty (LHCb) spectrometer at the Large Hadron Collider. The LHCb experiment ...is dedicated to studying charge conjugation and parity symmetry violation in the heavy flavor sector and rare decays of B mesons. The precise reconstruction of both the primary and secondary vertices, obtained by the VELO, is crucial in the selection of signal events containing b and c quarks and lifetime measurements. VELO consists of two retractable parts that operate at 8 mm from the interaction region. Its proximity to proton beams makes the LHCb VELO a place for studying radiation damage effects in silicon detectors in proton-proton and heavy-ion collisions. The latest results from radiation damage studies and their impact on the operation of the LHCb VELO after the first data-taking period (Run I) and the ongoing Run II are presented in this paper. The main macroscopic parameters, influenced by particle fluence, are described along with selected methods of their monitoring. All the results show that VELO sustains the impact of high fluence of radiation, and its performance will not change significantly until the end of Run II.
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