5,140 research outputs found
Feasibility of Using Bandwidth Efficient Modulation to Upgrade the CMS Tracker Readout Optical Links
Plans to upgrade the LHC after approximately 10 years of operation are
currently being considered at CERN. A tenfold increase in luminosity delivered
to the experiments is envisaged in the so-called Super LHC (SLHC). This will
undoubtedly give rise to significantly larger data volumes from the detectors,
requiring faster data readout. The possibility of upgrading the CMS Tracker
analog readout optical links using a bandwidth efficient digital modulation
scheme for deployment in the SLHC has been extensively explored at CERN.
Previous theoretical and experimental studies determined the achievable data
rate using a system based on Quadrature Amplitude Modulation (QAM) to be
~3-4Gbit/s (assuming no error correction is used and for an error rate of
~10-9). In this note we attempt to quantify the feasibility of such an upgrade
in terms of hardware implementation complexity, applicability to the high
energy physics (HEP) environment, technological feasibility and R&D effort
required.Comment: CERN CMS Note. 16 pages, 10 figure
FPGA-Based Tracklet Approach to Level-1 Track Finding at CMS for the HL-LHC
During the High Luminosity LHC, the CMS detector will need charged particle
tracking at the hardware trigger level to maintain a manageable trigger rate
and achieve its physics goals. The tracklet approach is a track-finding
algorithm based on a road-search algorithm that has been implemented on
commercially available FPGA technology. The tracklet algorithm has achieved
high performance in track-finding and completes tracking within 3.4 s on a
Xilinx Virtex-7 FPGA. An overview of the algorithm and its implementation on an
FPGA is given, results are shown from a demonstrator test stand and system
performance studies are presented.Comment: Submitted to proceedings of Connecting The Dots/Intelligent Trackers
2017, Orsay, Franc
Preliminary error budget for an optical ranging system: Range, range rate, and differenced range observables
Future missions to the outer solar system or human exploration of Mars may use telemetry systems based on optical rather than radio transmitters. Pulsed laser transmission can be used to deliver telemetry rates of about 100 kbits/sec with an efficiency of several bits for each detected photon. Navigational observables that can be derived from timing pulsed laser signals are discussed. Error budgets are presented based on nominal ground stations and spacecraft-transceiver designs. Assuming a pulsed optical uplink signal, two-way range accuracy may approach the few centimeter level imposed by the troposphere uncertainty. Angular information can be achieved from differenced one-way range using two ground stations with the accuracy limited by the length of the available baseline and by clock synchronization and troposphere errors. A method of synchronizing the ground station clocks using optical ranging measurements is presented. This could allow differenced range accuracy to reach the few centimeter troposphere limit
Radiation Testing of Electronics for the CMS Endcap Muon System
The electronics used in the data readout and triggering system for the
Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC)
particle accelerator at CERN are exposed to high radiation levels. This
radiation can cause permanent damage to the electronic circuitry, as well as
temporary effects such as data corruption induced by Single Event Upsets. Once
the High Luminosity LHC (HL-LHC) accelerator upgrades are completed it will
have five times higher instantaneous luminosity than LHC, allowing for
detection of rare physics processes, new particles and interactions. Tests have
been performed to determine the effects of radiation on the electronic
components to be used for the Endcap Muon electronics project currently being
designed for installation in the CMS experiment in 2013. During these tests the
digital components on the test boards were operating with active data readout
while being irradiated with 55 MeV protons. In reactor tests, components were
exposed to 30 years equivalent levels of neutron radiation expected at the
HL-LHC. The highest total ionizing dose (TID) for the muon system is expected
at the inner-most portion of the CMS detector, with 8900 rad over ten years.
Our results show that Commercial Off-The-Shelf (COTS) components selected for
the new electronics will operate reliably in the CMS radiation environment
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