A. Marzari Chiesa

The macro detector at the Gran Sasso Laboratory

Abstract The MACRO detector is presently under construction, its installation at Gran Sasso being planned to start in September 1987. It is a large area detector, the acceptance for isotropic particle fluxes being around 10 000 m 2 sr, designed to search for rare phenomena in the cosmic radiation. It makes use of three detection techniques: liquid scintillator counters, plastic streamer tubes, and track-etch. It will perform a search for GUT monopoles (or any supermassive charged penetrating particle), a survey of cosmic point sources of HE gammas and neutrinos, a systematic study of the penetrating cosmic ray muons, and will be sensitive to neutrino bursts from gravitational stellar collapses in the Galaxy.

Charged current elastic antineutrino interactions in propane

Abstract A sample of 766 antineutrino charged current elastic events has been used to extract the variation of the elastic cross section with antineutrino energy and the distribution of d N /d q 2 . The best fit value for the parameter M A obtained from these measurements is M A = 0.91 ± 0.04 GeV/ c 2 for M V = 0.84 GeV/ c 2 . A simultaneous determination of M A and M V gives M A = 0.94 ± 0.07, M V = 0.81

Operation and calibration of the Silicon Drift Detectors of the ALICE experiment during the 2008 cosmic ray data taking period

The calibration and performance of the Silicon Drift Detector of the ALICE experiment during the 2008 cosmic ray run will be presented. In particular the procedures to monitor the running parameters (baselines, noise, drift speed) are detailed. Other relevant parameters (SOP delay, time-zero, charge calibration) were also determined.

Charge collection in the Silicon Drift Detectors of the ALICE experiment

A detailed study of charge collection efficiency has been performed on the Silicon Drift Detectors (SDD) of the ALICE experiment. Three different methods to study the collected charge as a function of the drift time have been implemented. The first approach consists in measuring the charge at different injection distances moving an infrared laser by means of micrometric step motors. The second method is based on the measurement of the charge injected by the laser at fixed drift distance and varying the drift field, thus changing the drift time. In the last method, the measurement of the charge deposited by atmospheric muons is used to study the charge collection efficiency as a function of the drift time. The three methods gave consistent results and indicated that no charge loss during the drift is observed for the sensor types used in 99% of the SDD modules mounted on the ALICE Inner Tracking System. The atmospheric muons have also been used to test the effect of the zero-suppression applied to reduce the data size by erasing the counts in cells not passing the thresholds for noise removal. As expected, the zero suppression introduces a dependence of the reconstructed charge as a function of drift time because it cuts the signal in the tails of the electron clouds enlarged by diffusion effects. These measurements allowed also to validate the correction for this effect extracted from detailed Monte Carlo simulations of the detector response and applied in the offline data reconstruction.

Observation of radiation induced latchup in the readout electronics of NA50 multiplicity detector

During the data taking of the NA50 experiment, the CMOS digital pipeline chips (CDP) used for the readout of the multiplicity detector were exposed to high levels of radiation resulting in an ionizing radiation dose of more than 200 krad and displacement damage equivalent to 1 MeV neutron fluence of more than 5 � 10 11 eq. neutrons cm � 2 : Some of these chips showed anomalies of behaviour which we attribute to radiation induced latchup phenomena. Here we present the analysis of the data taken during the 1996, 1998 and 1999 ion runs together with the results of measurements performed in the laboratory. r 2002 Elsevier Science B.V. All rights reserved. PACS: 85.40.Qx; 61.80

Search for massive Monopoles at the Gran Sasso Laboratory with a large scale apparatus made up of scintillation counters, streamer tubes and CR-39 detectors

Abstract A large area detector to be used for a Magnetic Monopole search is in preparation. Complementary techniques, in particular the track-etch detector CR-39, will be used. The apparatus will cover a total area of at least 10 3 m 2 inside the Gran Sasso Laboratory. The role of CR-39 in the experiment and the structure of the track-etch detector are presented in this paper. Tests in progress are reported.

Status report of the macro experiment at gran sasso

Abstract The half of the MACRO detector, a large area Monopole, Astrophysics, Cosmic Ray Observatory is nearly completed in Hall B of the Gran Sasso Laboratory. One supermodule is already taken data and the remainder will be activated in few months. A general overview of the MACRO detector, together with its physics capabilities as far as the search for point sources of high energy neutrino is concerned, will be presented.

Automatized microscope for nuclear emulsion measurements

Abstract A microscope controlled by a Z8O microprocessor is described. The high spatial resolution allows to observe and measure in nuclear emulsions the decay of particles of very short lifetime.