62 research outputs found
Maximizing the Bandwidth Efficiency of the CMS Tracker Analog Optical Links
The feasibility of achieving faster data transmission using advanced digital
modulation techniques over the current CMS Tracker analog optical link is
explored. The spectral efficiency of Quadrature Amplitude Modulation
-Orthogonal Frequency Division Multiplexing (QAM-OFDM) makes it an attractive
option for a future implementation of the readout link. An analytical method
for estimating the data-rate that can be achieved using OFDM over the current
optical links is described and the first theoretical results are presented
Potential Upgrade of the CMS Tracker Analog Readout Optical Links Using Bandwidth Efficient Digital Modulation
The potential application of advanced digital communication schemes in a
future upgrade of the CMS Tracker readout optical links is currently being
investigated at CERN. We show experimentally that multi-Gbit/s data rates are
possible over the current 40 MSamples/s analog optical links by employing
techniques similar to those used in ADSL. The concept involves using one or
more digitally-modulated sinusoidal carriers in order to make efficient use of
the available bandwidth.Comment: Presented at LECC 2006, Valencia, Spain. 5 pages, 11 figures
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
Characterisation of irradiated thin silicon sensors for the CMS phase II pixel upgrade
The high luminosity upgrade of the Large Hadron Collider, foreseen for 2026, necessitates the replacement of the CMS experiment's silicon tracker. The innermost layer of the new pixel detector will be exposed to severe radiation, corresponding to a 1 MeV neutron equivalent fluence of up to Phi(eq) = 2x10(16) cm(-2), and an ionising dose of approximate to 5 MGy after an integrated luminosity of 3000 fb(-1). Thin, planar silicon sensors are good candidates for this application, since the degradation of the signal produced by traversing particles is less severe than for thicker devices. In this paper, the results obtained from the characterisation of 100 and 200 mu m thick p-bulk pad diodes and strip sensors irradiated up to fluences of Phi(eq) = 1.3 x 10(16) cm(-2) are shown.Peer reviewe
P-Type Silicon Strip Sensors for the new CMS Tracker at HL-L-HC
Abstract: The upgrade of the LHC to the High-Luminosity LHC (HL-LHC) is expected to increase
the LHC design luminosity by an order of magnitude. This will require silicon tracking detectors
with a significantly higher radiation hardness. The CMS Tracker Collaboration has conducted an
irradiation and measurement campaign to identify suitable silicon sensor materials and strip designs
for the future outer tracker at the CMS experiment. Based on these results, the collaboration has
chosen to use n-in-p type silicon sensors and focus further investigations on the optimization of that
sensor type
A Timing, Trigger, and Control System With Picosecond Precision Based on 10 Gbit/s Passive Optical Networks for High-Energy Physics
The Large Hadron Collider (LHC) experiments will have their timing, trigger, and control (TTC) system upgraded as a consequence of the need for higher bandwidth and components which are obsolete. In this article, we present a TTC based on passive optical networks (PONs). TTC-PON is a point-to-multipoint bidirectional TTC system based on the 10 Gbit/s International Telecommunications Union (ITU) XG-PON technology and modern field-programmable gate array (FPGA) devices. Each master can handle up to 64 slaves through a fully passive network, delivering a fixed-phase recovered clock to all the destinations with less than 5-ps jitter. TTC-PON pushes the limits of the PON technology by exploiting cutting-edge custom protocols on top of the commercially available XG-PON optical modules. It can potentially reuse the current optical fiber infrastructure already installed in the experiments and allows for high flexibility in terms of partitioning, which can ease future upgrades of the TTC network. The system features a picosecond-level on-the-fly phase monitoring for each slave’s recovered clock by exploiting the bidirectionality of the network. In addition, a full set of link-quality monitoring tools was developed, allowing real-time performance monitoring. An overview of the tailored protocols will be given together with the details on the system implementation, operation, and performance. A discussion on the characterization campaign of more than 1000 optical modules delivered to the first implementation of the TTC-PON system will be drawn
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