Production and commissioning performance tests of the read-out driver boards for the hadronic tile calorimeter of the ATLAS detector at the LHC
The ATLAS hadronic tile calorimeter detector (TileCal) is an iron-scintillating tiles sampling calorimeter designed to operate at the Large Hadron Collider (LHC) accelerator at CERN. The central element of the back-end system of the TileCal detector is a 9U VME read-out driver (ROD) board. The operation of the TileCal calorimeter requires a total of 32 ROD boards. We report here on the overall electrical performance of the ROD boards during their production phase and during their first operation at the ATLAS commissioning setup at CERN. We report also on the real time operation and performance of the ROD digital signal processors (DSPs) on the first cosmic data runs taken at the commissioning setup. The DSP operation is based on the use of optimal filtering algorithms for the signal amplitude, pedestal and time online reconstruction and which, in addition, monitor the quality of the reconstructions
The Read-Out Driver for the RPC of the ATLAS Muon Spectrometer
The spectrometer of the ATLAS experiment has been designed to identify muon tracks with transverse momenta up to 1 TeV/c. Its barrel section is made of monitored drift tubes and resistive plate chambers (RPCs) arranged into 32 sectors, to form two wheels surrounding the interaction point. The RPC subsystem provides the level-1 trigger in the barrel and it is read out by a specific DAQ system. On-detector electronics pack the RPC data in frames with an event number assigned by the trigger logic and transmit them to the counting room optically. Data from each sector are then routed together to a read-out driver (ROD) board. This is a custom processor that parses the frames, checks their coherence and builds a data structure for all the RPCs of one of the 32 sectors of the spectrometer. Each ROD sends the event fragments to a read-out buffer for further event building and analysis. The ROD is a VME64x board, designed around two Xilinx Virtex-II FPGAs and an ARM7 microcontroller. In this paper we describe the system architecture, the event binding algorithms and the monitoring features embedded into the design. The board is in production and will be deployed in the first ATLAS runs.
The development of biological systematics : Antoine-Laurent de Jussieu, nature, and the natural system
A reevaluation of the history of biological systematics that discusses the formative years of the so-called natural system of classification in the eighteenth and nineteenth centuries. Shows how classifications came to be treated as conventions; systematic practice was not linked to clearly articulated theory; there was general confusion over the "shape" of nature; botany, elements of natural history, and systematics were conflated; and systematics took a position near the bottom of the hierarchy of sciences.