P. Tempesta

A high resolution beam telescope built with double sided silicon strip detectors

A compact and portable beam telescope has been built using four 1.92 × 1.92 cm2 double sided silicon microstrip detectors with 50 μm read-out pitch. Tests using 50 GeV pions have shown that the beam position can be defined with a precision of 5 and 7 μm on the p-side and n-side respectively with an overall detection efficiency of 93.0%.

THE NEW ALEPH SILICON VERTEX DETECTOR

The ALEPH collaboration, in view of the importance of effective vertex detection for the Higgs boson search at LEP 2, decided to upgrade the previous vertex detector. Main changes were an increased length (+/- 20 cm), a higher granularity for r phi view (50 mu m), a new preamplifier (MX7 rad hard chip), a polymide (upilex) fan-out on z side to carry the signals from the strips to the front-end electronics outside the fiducial region reducing consequently the passive material in the central region by a factor of two. The detector, the running experience and its performance will be described

Beam test results for single- and double-sided silicon detector prototypes of the CMS central detector

We report the results of two beam tests performed in July and September 1995 at CERN using silicon microstrip detectors of various types: single sided, double sided with small angle stereo strips, double sided with orthogonal strips, double sided with pads. For the read-out electronics use was made of Preshape32, Premux128 and VA1 chips. The signal to noise ratio and the resolution of the detectors was studied for different incident angles of the incoming particles and for different values of the detector bias voltage. The goal of these tests was to check and improve the performances of the prototypes for the CMS Central Detector.

Construction and performance of the new ALEPH Vertex Detector

A new Silicon Vertex Detector was developed for the ALEPH experiment and first installed for the high energy run at 130 GeV at the end of 1995. The detector has an active length of 40 cm and consists of two concentric layers of silicon wafers with double-sided readout. It extends the angular coverage, has only half the passive material as the former detector in the tracking volume and is radiation hard to cope with the higher level of radiation background expected for the LEP2 phase. The construction and the performance of the detector is described.

Study of radiation damage and substrate resistivity effects from beam test of silicon microstrip detectors using LHC readout electronics

Abstract We present the beam test results of single-sided silicon microstrip detectors, with different substrate resistivities. The effects of radiation damage are studied for a detector irradiated to a fluence of 2.4×10 14 n / cm 2 . The detectors are read out with the APV6 chip, which is compatible with the 40 MHz LHC clock. The performance of different detectors and readout modes are studied in terms of signal-to-noise ratio and efficiency.

CHARACTERISATION AND SIMULATION OF A SINGLE-SIDED, N+ ON N SILICON MICROSTRIP DETECTOR BEFORE AND AFTER NEUTRON IRRADIATION

Abstract Capacitance, resistance and current measurements were carried out on single-sided, n+ on n silicon strip detectors. We studied the type inversion after irradiating the detectors with neutron fluences up to 8.3×10 13 neutron / cm 2 . To understand the macroscopic irradiation effects, a SPICE model of the detector was developed. Simulating the capacitance measurements, we were able to reproduce the measured frequency dependence of the relevant capacitances, both for non-irradiated and for irradiated detectors.

The Aleph hadron calorimeter strip readout scanner

Abstract The strip readout system of the Aleph streamer tubes hadron calorimeter is described. The system is based on a Fastbus module named ASTROS (Aleph STrip ReadOut Scanner) which performs data reduction and formatting.

Monitoring the Stability of the ALEPH Vertex Detector

Abstract The ALEPH Silicon Vertex Detector features an optical fibre laser system to monitor its mechanical stability. The operating principle and the general performance of the laser system are described. The experience obtained during 1997 and 1998 operations confirms the important role that such a system can have with respect to the detector alignment requirements. In particular, the laser system has been used to monitor short-term temperature-related effects and long-term movements. These results and a description of the laser-based alignment correction applied to the 1998 data are presented.

THE GAIN MONITORING-SYSTEM OF THE ALEPH-HADRON CALORIMETER

Abstract The gas gain monitoring system of the Aleph hadron calorimeter is described. The dependence of the charge response to a) the ratio between the pressure to temperature and b) the gas mixture parameters (Ar/CO2 ratio and isobutane percentage) have been determined. The total gain variation is measured with a precision of about 0.4%.

Test beam results on irradiated silicon detectors for the CMS Silicon Strip Tracker

Abstract We report the results of test beams performed at CERN using irradiated microstrip silicon detectors. The detectors were single- and double-sided devices, produced by different manufacturers and irradiated with neutrons at various fluences up to 3.6 × 10 13 n/cm 2 . Signal-to-noise ratio, resolution and efficiency were studied for different values of the incidence angle, of the detector temperature and of the read-out pitch, as a function of the detector bias voltage. The goal of these tests was to optimize the design of the final prototypes for the CMS Silicon Strip Tracker.