The CMS silicon tracker at LHC

The paper describes the Silicon Tracking System of the Compact Muon Solenoid (CMS) experiment that is foreseen to collect events from p-p collision at the E-cm = 14 TeV at the CERN future Large Hadron Collider (LHC). The proposed system consists of four layers of silicon microstrip detectors placed between the two inner layers of the pixel detector and the outer microstrip gas chamber system. The barrel part covers the eta region up to 1.8, instrumenting the central radial region between 20 and 50 cm. The forward-backward disks extend the coverage up to eta = 2.6. This paper will review the main characteristics and performances of the system, the actual status of the R&D activities that we are carrying on, and the status of the milestones we have to fulfill in view of the Technical Design Report expected at the end of the year. (C) 1998 Elsevier Science B.V. All rights reserved

The CMS silicon tracker at LHC

The paper describes the Silicon Tracking System of the Compact Muon Solenoid (CMS) experiment that is foreseen to collect events from p-p collision at the E-cm = 14 TeV at the CERN future Large Hadron Collider (LHC). The proposed system consists of four layers of silicon microstrip detectors placed between the two inner layers of the pixel detector and the outer microstrip gas chamber system. The barrel part covers the eta region up to 1.8, instrumenting the central radial region between 20 and 50 cm. The forward-backward disks extend the coverage up to eta = 2.6. This paper will review the main characteristics and performances of the system, the actual status of the R&D activities that we are carrying on, and the status of the milestones we have to fulfill in view of the Technical Design Report expected at the end of the year. (C) 1998 Elsevier Science B.V. All rights reserved

The CMS Silicon Tracker Detector: an Overview of the R&D Current Status

The paper describes the Silicon Tracking System of the Compact Muon Solenoid ( CMS) and reviews the most recent results of the R&D activity on radiation resistant microstrip silicon detectors. The Silicon Tracker of CMS consists of 5 layers of microstrip detectors in the barrel and 10 disks on either side of the end-cap region. The detectors of the innermost layers ( 22.5 cm radial distance from the beam pipe) are required to operate up to an integrated fluence of 1.6 10 ^14 1-MeV-equivalent neutrons per cm2. The results, obtained with single-sided prototypes irradiated with a neutron fluence up to 2*10^14 n/cm2 in terms of signal-to-noise ratio, efficiency and spatial resolution are described. We also show a comparison between device simulations, laboratory measurements and experimental results. Lastly we describe the complex system prototypes which have been recently built to address the system aspects of such a large silicon tracker

The CMS silicon microstrip detectors: Research and development

A large quantity of silicon microstrip detectors is foreseen to be used as part of the CMS tracker. A specific research and development program has been carried out with the aim of defining layouts and technological solutions suitable for the use of silicon detectors in high radiation environment. Results presented here summarise this work on many research areas such as techniques for device manufacturing, pre- and post-irradiation electrical characterization, silicon bulk defects analysis and simulations, system performance analytical calculations and simulations and test beam analysis. As a result of this work we have chosen to use single-sided, AC-coupled, poly silicon biased, 300 mu m thick, p(+) on n substrate detectors. We feel confident that these devices will match the required performances for the CMS tracker provided they can be operated at bias voltages as high as 500 V. Such high-voltage devices have been succesfully manufactured and we are now concentrating our efforts in enhancing yield and reliability. (C) 1999 Elsevier Science B.V. All rights reserved

Test results of heavily irradiated Si detectors

A large use of silicon microstrip detectors is foreseen for the intermediate part of the CMS tracker. A specific research and development program has been carried out with the aim of finding design layouts and technological solutions for allowing silicon microstrip detectors to be reliably used on a high radiation level environment. As a result of this work single sided, AC-coupled, polysilicon biased, 300 mu m thick, p(+) on n substrate detectors were chosen. Irradiation tests have been performed on prototypes up to fluence 2 x 10(14) n/cm(2). The detector performances do not significantly change if the detectors are biased well above the depletion voltage. S/N is reduced by less than 20%, still enough to insure a good efficiency and space resolution. Multiguard structures has been developed in order to reach high voltage operation (above 500 V). (C) 1999 Published by Elsevier Science B.V. All rights reserved

The CMS silicon tracker

The new silicon tracker layout (V4) is presented. The system aspects of the construction are discussed together with the expected tracking performance. Because of the high radiation environment in which the detectors will operate, particular care has been devoted to the study of the characteristics of heavily irradiated detectors. This includes studies on performance (charge collection, cluster size, resolution, efficiency) as a function of the bias voltage, integrated fluence, incidence angle and temperature. (C) 1998 Elsevier Science B.V. All rights reserved

Test results of heavily irradiated Si detectors

A large use of silicon microstrip detectors is foreseen for the intermediate part of the CMS tracker. A specific research and development program has been carried out with the aim of finding design layouts and technological solutions for allowing silicon microstrip detectors to be reliably used on a high radiation level environment. As a result of this work single sided, AC-coupled, polysilicon biased, 300 μn thick, p + on n substrate detectors were chosen. Irradiation tests have been performed on prototypes up to fluence 2 × 10 14 n/cm 2. The detector performances do not significantly change if the detectors are biased well above the depletion voltage. S/N is reduced by less than 20%, still enough to insure a good efficiency and space resolution. Multiguard structures has been developed in order to reach high voltage operation (above 500 V). © 1999 Published by Elsevier Science B.V. All rights reserved