Commissioning and Calibrating the CMS Silicon Strip Tracker

The data acquisition system for the CMS Silicon Strip Tracker (SST) is based around a custom analogue front-end ASIC, an analogue optical link system and an off-detector VME board that performs digitization, zero-suppression and data formatting. A complex procedure is required to optimally configure, calibrate and synchronize the 107 channels of the SST readout system. We present an overview of this procedure, which will be used to commission and calibrate the SST during the integration, Start-Up and operational phases of the experiment. Recent experiences from the CMS Magnet Test Cosmic Challenge and system tests at the Tracker Integration Facility are also reported

Monitoring the CMS strip tracker readout system

The CMS Silicon Strip Tracker at the LHC comprises a sensitive area of approximately 200 m2 and 10 million readout channels. Its data acquisition system is based around a custom analogue front-end chip. Both the control and the readout of the front-end electronics are performed by off-detector VME boards in the counting room, which digitise the raw event data and perform zero-suppression and formatting. The data acquisition system uses the CMS online software framework to configure, control and monitor the hardware components and steer the data acquisition. The first data analysis is performed online within the official CMS reconstruction framework, which provides many services, such as distributed analysis, access to geometry and conditions data, and a Data Quality Monitoring tool based on the online physics reconstruction. The data acquisition monitoring of the Strip Tracker uses both the data acquisition and the reconstruction software frameworks in order to provide real-time feedback to shifters on the operational state of the detector, archiving for later analysis and possibly trigger automatic recovery actions in case of errors. Here we review the proposed architecture of the monitoring system and we describe its software components, which are already in place, the various monitoring streams available, and our experiences of operating and monitoring a large-scale system

Using XDAQ in Application Scenarios of the CMS Experiment

XDAQ is a generic data acquisition software environment that emerged from a rich set of of use-cases encountered in the CMS experiment. They cover not the deployment for multiple sub-detectors and the operation of different processing and networking equipment as well as a distributed collaboration of users with different needs. The use of the software in various application scenarios demonstrated the viability of the approach. We discuss two applications, the tracker local DAQ system for front-end commissioning and the muon chamber validation system. The description is completed by a brief overview of XDAQ.Comment: Conference CHEP 2003 (Computing in High Energy and Nuclear Physics, La Jolla, CA

Angiotensin Type 2 Receptor Stimulation Increases Renal Function in Female, but Not Male, Spontaneously Hypertensive Rats

Accumulating evidence suggests that the protective pathways of the renin–angiotensin system are enhanced in women, including the angiotensin type 2 receptor (AT 2 R), which mediates vasodilatory and natriuretic effects. To provide insight into the sex-specific ability of pharmacological AT 2 R stimulation to modulate renal function in hypertension, we examined the influence of the AT 2 R agonist, compound 21 (100–300 ng/kg per minute), on renal function in 18- to 19-week-old anesthetized male and female spontaneously hypertensive rats. AT 2 R stimulation significantly increased renal blood flow in female hypertensive rats ( P Treatment &lt;0.001), without influencing arterial pressure. For example, at 300 ng/kg per minute of compound 21, renal blood flow increased by 14.3±1.8% from baseline. Furthermore, at 300 ng/kg per minute of compound 21, a significant increase in urinary sodium excretion was observed in female hypertensive rats (+180±59% from baseline; P &lt;0.05 versus vehicle-treated rats). This was seen in the absence of any major change in glomerular filtration rate, indicating that the natriuretic effects of AT 2 R stimulation were likely the result of altered renal tubular function. Conversely, we did not observe any significant effect of AT 2 R stimulation on renal hemodynamic or excretory function in male hypertensive rats. Finally, gene expression studies confirmed greater renal AT 2 R expression in female than in male hypertensive rats. Taken together, acute AT 2 R stimulation enhanced renal vasodilatation and sodium excretion without concomitant alterations in glomerular filtration rate in female hypertensive rats. Chronic studies of AT 2 R agonist therapy on renal function and arterial pressure in hypertensive states are now required to establish the suitability of AT 2 R as a therapeutic target for cardiovascular disease, particularly in women. </jats:p

Construction and commissioning of a technological prototype of a high-granularity semi-digital hadronic calorimeter

A large prototype of 1.3m3 was designed and built as a demonstrator of the semi-digital hadronic calorimeter (SDHCAL) concept proposed for the future ILC experiments. The prototype is a sampling hadronic calorimeter of 48 units. Each unit is built of an active layer made of 1m2 Glass Resistive Plate Chamber(GRPC) detector placed inside a cassette whose walls are made of stainless steel. The cassette contains also the electronics used to read out the GRPC detector. The lateral granularity of the active layer is provided by the electronics pick-up pads of 1cm2 each. The cassettes are inserted into a self-supporting mechanical structure built also of stainless steel plates which, with the cassettes walls, play the role of the absorber. The prototype was designed to be very compact and important efforts were made to minimize the number of services cables to optimize the efficiency of the Particle Flow Algorithm techniques to be used in the future ILC experiments. The different components of the SDHCAL prototype were studied individually and strict criteria were applied for the final selection of these components. Basic calibration procedures were performed after the prototype assembling. The prototype is the first of a series of new-generation detectors equipped with a power-pulsing mode intended to reduce the power consumption of this highly granular detector. A dedicated acquisition system was developed to deal with the output of more than 440000 electronics channels in both trigger and triggerless modes. After its completion in 2011, the prototype was commissioned using cosmic rays and particles beams at CERN.Comment: 49 pages, 41 figure

Performance of Glass Resistive Plate Chambers for a high granularity semi-digital calorimeter

A new design of highly granular hadronic calorimeter using Glass Resistive Plate Chambers (GRPCs) with embedded electronics has been proposed for the future International Linear Collider (ILC) experiments. It features a 2-bit threshold semi-digital read-out. Several GRPC prototypes with their electronics have been successfully built and tested in pion beams. The design of these detectors is presented along with the test results on efficiency, pad multiplicity, stability and reproducibility.Comment: 16 pages, 15 figure

Recent Results on the Performance of the CMS Tracker Readout System

The CMS Silicon Tracker comprises a complicated set of hardware and software components that have been thoroughly tested at CERN before final integration of the Tracker. A vertical slice of the full readout chain has been operated under near-final conditions. In the absence of the tracker front-end modules, simulated events have been created within the FED (Front End Driver) and used to test the readout reliability and efficiency of the final DAQ (Data Acquisition). The data are sent over the S-Link 64 bit links to the FRL(Fast Readout Link) modules at rates in excess of 200 MBytes/s per FED depending on setup and conditions. The current tracker DAQ is fully based on the CMS communication and acquisition tool XDAQ. This paper discusses setup and results of a vertical slice of the full Tracker final readout system comprising 2 full crates of FEDs, 30 in total, read out through 1 full crate of final FRL modules. This test is to complement previous tests done at Imperial College[3] taking them to the next level in order to prove that a complete crate of FRLs using the final DAQ system, including all subcomponents of the final system both software and hardware with the exception of the detector modules themselves, is capable of sustained readout at the desired rates and occupancy of the CMS Tracker. Simulated data are created with varying hit occupancy (1-10%) and Poisson distributed trigger rates (<200KHz) and the resulting behaviour of the system is recorded. Data illustrating the performance of the system and data readout are presented

Air shower simulation for background estimation in muon tomography of volcanoes

International audienceOne of the main sources of background for the radiography of volcanoes using atmospheric muons comes from the accidental coincidences produced in the muon telescopes by charged particles belonging to the air shower generated by the primary cosmic ray. In order to quantify this background effect, Monte Carlo simulations of the showers and of the detector are developed by the TOMUVOL collaboration. As a first step, the atmospheric showers were simulated and investigated using two Monte Carlo packages, CORSIKA and GEANT4.We compared the results provided by the two programs for the muonic component of vertical proton-induced showers at three energies: 1, 10 and 100 TeV. We found that the spatial distribution and energy spectrum of the muons were in good agreement for the two codes