The LHCb detector and its electronics architecture are optimized for the measurement of b-physics at LHC. A complete electronics system for the first phase of LHCb has been produced and installed, ...and this paper presents the architecture and some examples of its implementation. Research and development are already starting towards a proposed LHCb upgrade and the second half of the paper describes the new electronics architecture and some of the technical challenges it presents.
The LHCb RICH photon detector system Wyllie, K.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2008, Letnik:
591, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The LHCb experiment at the CERN Large Hadron Collider will employ two Ring Imaging Cherenkov (RICH) detectors for particle identification. The Cherenkov photons will be detected by planes of photon ...detectors covering a total active surface area of 2.1
m
2. The detector chosen for this task is the pixel hybrid photon detector (HPD). This combines silicon pixel sensors, integrated electronics and high-density interconnects together with vacuum-tube technology to produce an efficient, low-noise detector sensitive to single photons. For the complete photon detector system of the LHCb RICH, 484 such HPDs are required and these have been fully integrated into detector modules. Specific aspects of this integration within the RICH system are described together with the steps taken to ensure the efficiency and reliability of the detector in the harsh environment of LHCb.
The LHCb experiment at the CERN Large Hadron Collider will use ring-imaging Cherenkov detectors for particle identification. By measuring rings of Cherenkov photons generated by elementary particles ...traversing a radiative medium, these particles can be identified across a wide range of momenta. The photons will be measured by a new type of detector, the pixel hybrid photon detector (HPD). In total, 484 HPDs will be used, providing ∼500,000 channels of data. Specific readout electronics have been developed for processing the data from the HPDs, and this paper describes the design and testing of these devices together with the final system to be used in the experiment. Emphasis is on the application-specific integrated circuits that are encapsulated within the HPDs, allowing high channel density and low noise. These are subject to the strict requirements of efficient photon detection and reliability within the harsh environment of the experiment. Special interconnect techniques developed for this application are described. Finally, the additional electronics infrastructure to readout the full system of 500,000 channels is outlined, including data transmission and power distribution.
VeloPix ASIC development for LHCb VELO upgrade van Beuzekom, M.; Buytaert, J.; Campbell, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Letnik:
731
Journal Article
Recenzirano
The upgrade of the LHCb experiment, planned for 2018, will transform the readout of the entire experiment to a triggerless system operating at 40MHz. All data reduction algorithms will be run in a ...high level software farm, and will have access to event information from all subdetectors. This approach will give great power and flexibility in accessing the physics channels of interest in the future, in particular the identification of flavour tagged events with displaced vertices. The data acquisition and front end electronics systems require significant modification to cope with the enormous throughput of data. For the silicon vertex locator (VELO) a dedicated development is underway for a new ASIC, VeloPix, which will be a derivative of the Timepix/Medipix family of chips. The chip will be radiation hard and be able to cope with pixel hit rates of above 500MHz, highly non-uniformly distributed over the 2cm2 chip area. The chip will incorporate local intelligence in the pixels for time-over-threshold measurements, time-stamping and sparse readout. It must in addition be low power, radiation hard, and immune to single event upsets. In order to cope with the datarates and use the pixel area most effectively, an on-chip data compression scheme will integrated. This paper will describe the requirements of the LHCb VELO upgrade, and give an overview of the digital architecture being developed specifically for the readout chip.
Vascular biglycan contributes to atherosclerosis development and increased biglycan expression correlates with increased atherosclerosis. However, mice deficient in biglycan have either no reduction ...in atherosclerosis or an unexpected increase in atherosclerosis. Biglycan deficient mice have systemically elevated TGF-β, likely due to lack of sequestration of TGF-β in the extracellular matrix. The purpose of this study was to determine if prevention of TGF-β elevations in biglycan deficient mice affected atherosclerosis development.
Biglycan deficient mice were crossed to Ldlr deficient mice. Diabetes was induced via streptozotocin and all mice were fed a high cholesterol diet. Diabetic biglycan wild type and biglycan deficient Ldlr deficient mice were injected with the TGF-β neutralizing antibody 1D11 or the irrelevant control antibody 13C4.
Biglycan deficient mice had significantly elevated plasma TGF-β levels, which was further increased by diabetes, and significantly increased atherosclerosis. There was a significant correlation between TGF-β concentrations and atherosclerosis. However, despite nearly complete suppression of plasma TGF-β levels in mice treated with the TGF-β neutralizing antibody 1D11, there was no significant difference in atherosclerosis between mice with elevated TGF-β levels and mice with suppressed TGF-β levels.
The increased atherosclerosis in biglycan deficient mice does not appear to be due to elevations in TGF-β.
•Increased vascular biglycan leads to increased atherosclerosis.•However, biglycan deficiency does not appear to lead to decreased atherosclerosis.•Biglycan deficiency leads to increased circulating TGF-β.•However, neutralization of TGF-β has no effect on atherosclerosis development.
PDF
