L. Borrello

Determination of the charge collection efficiency in neutron irradiated silicon detectors

The charge collected from p-type silicon strip sensors irradiated to SuperLHC fluences has been determined in a beta source using fast front-end electronics. The bias voltage dependence of the collected charge and the efficiency have been measured before and after accelerated annealing. Predictions of the performance at the LHC are derived.

Determination of the Charge Collection Efficiency in Neutron Irradiated Silicon Detectors

The charge collected from p-type silicon strip sensors irradiated to SuperLHC fluences has been determined with a beta source using fast front-end electronics. The bias voltage dependence of the collected charge and the hit detection efficiency have been measured before and after accelerated annealing. Predictions of the performance at the SuperLHC are derived.

Study of edge effects in the breakdown process of p(+) on n-bulk silicon diodes

Abstract The paper describes the role of the n + edge implants in the breakdown process of p + on n-bulk silicon diodes. Laboratory measurements and simulation studies are presented on a series of test structures aimed at an optimization of the design in the edge region. The dependence of the breakdown voltage on the geometrical parameters of the devices is discussed in detail. Design rules are extracted for the use of n + -layers along the scribe line to avoid surface conduction of current generated by the exposed edges. The effect of neutron irradiation has been studied up to a fluence of 1.8×10 15 cm −2 .

Results with microstrip detectors produced by STMicroelectronics for the CMS tracker

The paper presents the results of an extensive set of measurements performed on silicon microstrip sensors produced by STMicroelectronics for the CMS Tracker. 5 00 and 6 00 technologies were used to process several series of detector prototypes. Detectors 300 mm thick were produced on 5 00 wafers and fully characterized. A new design on 500 mm thick wafers with 6 00 technology has been recently implemented. The performance of three different layouts has been investigated in terms of macroscopic electrical parameters and radiation resistance. r 2002 Elsevier Science B.V. All rights reserved.

Performance of 500-mu-m thick silicon microstrip detectors after irradiation

Abstract This paper investigates the performance of 500 μm thick silicon microstrip detectors before and after heavy irradiation. Prototype sensors, produced by STMicroelectronics, have been extensively studied using laboratory measurements, a radioactive source and a beam of minimum ionising particles. The comparison with a standard 300 μm sensor shows that the collected charge in thick devices scales linearly with thickness. By over-depleting the irradiated devices, the pre-irradiated charge collection efficiency is fully recovered. The measured noise is in good agreement with expectations. Although more work is needed, the paper shows that 500 μm thick devices are a promising technology for very large tracking systems.

Performance of irradiated and non-irradiated 500 /spl mu/m thick-silicon microstrip detectors

The decision taken by the CMS experiment to build a tracker entirely based on silicon detectors has made necessary the use of thicker sensors instead of the usual 300-/spl mu/m sensors for the outer part of the detector. We first present results on the performance of 500-/spl mu/m-thick detectors, before and after neutron irradiation, bonded to the CMS tracker front-end electronics. Laboratory measurements show that the total collected charge scales linearly with thickness when compared with a 300-/spl mu/m module, and the measured noise is in good agreement with expectations. The results obtained confirm the feasibility of large-area silicon trackers.

The Data Quality Monitoring Software for the CMS experiment at the LHC

The Data Quality Monitoring (DQM) Software is a central tool in the CMS experiment. Its flexibility allows for integration in several key environments: online, for real-time detector monitoring; offline, for the final, fine-grained data certification; release validation, to constantly validate the functionalities and the performance of the reconstruction software; in Monte Carlo productions. Since the end of data taking at a center of mass energy of 8 TeV, the environment in which the DQM lives has undergone fundamental changes. In this contribution the usage of the DQM software in the different environments and its integration in the CMS Reconstruction Software Framework (CMSSW) and in all production workflows are presented, with emphasis on recent developments and improvement in advance of the LHC restart at 13 TeV.

The CMS Data Quality Monitoring Software: Experience and future improvements

The Data Quality Monitoring Software proved to be a central tool in the Compact Muon Solenoid experiment. Its flexibility allowed its integration in several environments: online, for real-time detector monitoring; offline, for the final, fine-grained data certification. The usage of the Data Quality Monitoring software in the different environments and its integration in the Compact Muon Solenoid reconstruction software framework and in all production work-flows are presented. The main technical challenges and the adopted solutions to them will be also discussed with emphasis on functionality, longterm robustness and performance.

High statistics study of radiation damage on silicon microstrip detectors

This paper investigates the performance of silicon microstrip detectors after heavy irradiation. Full-size prototype sensors (53 /spl times/ 64 mm/sup 2/) designed for the CMS Tracker have been irradiated with protons and extensively studied in the laboratory and using a beam of minimum ionising particles operated at low temperature as foreseen for the Large Hadron Collider. We present results of large statistics measurements of collected charge, noise, position resolution, and hit finding efficiency for these irradiated detectors.

Performance of irradiated and non-irradiated 500 μm thick-silicon microstrip detectors

The decision-taken by the CMS experiment to build a tracker entirely based on silicon detectors has made necessary the use of thicker sensors instead of the usual 300 /spl mu/m ones for the outer part of the detector. We present first results on the performance of 500 /spl mu/m thick detectors, before and after neutron irradiation, bonded to the CMS tracker front-end electronics. Laboratory measurements show that the total collected charge scales linearly with thickness when compared with a 300 /spl mu/m module and the measured noise is in good agreement with expectations. The results obtained confirm the feasibility of large area silicon trackers.