1,901 research outputs found
Run 2 Upgrades to the CMS Level-1 Calorimeter Trigger
The CMS Level-1 calorimeter trigger is being upgraded in two stages to
maintain performance as the LHC increases pile-up and instantaneous luminosity
in its second run. In the first stage, improved algorithms including
event-by-event pile-up corrections are used. New algorithms for heavy ion
running have also been developed. In the second stage, higher granularity
inputs and a time-multiplexed approach allow for improved position and energy
resolution. Data processing in both stages of the upgrade is performed with
new, Xilinx Virtex-7 based AMC cards.Comment: 10 pages, 7 figure
Material Cycles and Chemicals: Dynamic Material Flow Analysis of Contaminants in Paper Recycling
This study provides
a systematic approach for assessment of contaminants
in materials for recycling. Paper recycling is used as an illustrative
example. Three selected chemicals, bisphenol A (BPA), diethylhexyl
phthalate (DEHP) and mineral oil hydrocarbons (MOHs), are evaluated
within the paper cycle. The approach combines static material flow
analysis (MFA) with dynamic material and substance flow modeling.
The results indicate that phasing out of chemicals is the most effective
measure for reducing chemical contamination. However, this scenario
was also associated with a considerable lag phase (between approximately
one and three decades) before the presence of chemicals in paper products
could be considered insignificant. While improved decontamination
may appear to be an effective way of minimizing chemicals in products,
this may also result in lower production yields. Optimized waste material
source-segregation and collection was the least effective strategy
for reducing chemical contamination, if the overall recycling rates
should be maintained at the current level (approximately 70% for Europe).
The study provides a consistent approach for evaluating contaminant
levels in material cycles. The results clearly indicate that mass-based
recycling targets are not sufficient to ensure high quality material
recycling
Triggering on electrons, jets and tau leptons with the CMS upgraded calorimeter trigger for the LHC RUN II
The Compact Muon Solenoid (CMS) experiment has implemented a sophisticated two-level online selection system that achieves a rejection factor of nearly 10e5. During Run II, the LHC will increase its centre-of-mass energy up to 13 TeV and progressively reach an instantaneous luminosity of 2e34cm-2s-1. In order to guarantee a successful and ambitious physics programme under this intense environment, the CMS Trigger and Data acquisition (DAQ) system has been upgraded. A novel concept for the L1 calorimeter trigger is introduced the Time Multiplexed Trigger (TMT). In this design, nine main receive each all of the calorimeter data from an entire event provided by 18 preprocessors. This design is not different from that of the CMS DAQ and HLT systems. The advantage of the TMT architecture is that a global view and full granularity of the calorimeters can be exploited by sophisticated algortihms. The goal is to maintain the current thresholds for calorimeter objects and improve the performance for their selection. The performance of these algorithms will be demonstrated, both in terms of efficiency and rate reduction. The callenging aspects of the pile-up mitigation and firmware design will be presented
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