C. Gustavino

A glass resistive plate chamber for large experiments

Abstract A new type of glass electrode RPC is described. The design is conceived to allow a large and fast production, good performance and an easy detector operation. These characteristics make the detector suitable for very large arrays, such as future neutrino experiments.

A glass spark counter for high rate environments

The performance of a glass spark counter prototype, built with glass electrodes of about 1010 Ω cm volume resistivity, is described. The measurem

Tests of OPERA RPC detectors

OPERA is part of the CNGS project and it is an experiment dedicated to the observation of long-baseline numu into nutau oscillations through tau appearance. Resistive Plate Chambers (RPCs) with bakelite electrodes are used to instrument the 2 cm gaps between the magnetized iron slabs of the two spectrometers. The RPC installation ended in may 2004 on the first spectrometer and in march 2005 on the second one. Before the installation, every RPC is subjected to a complete test chain in order to reject the poorer quality detectors. The tests are performed in dedicated facilities to ensure the proper RPC gluing, to measure its electrical properties and to verify the response to cosmic rays and the intrinsic noise levels. We have also tested the long term stability of real size OPERA RPC prototypes operated at cosmic ray fluxes for more than one year. On small size prototypes we are performing studies on the gas mixtures in order to reduce the total charge released in the gas for each detector count. The validation of the installed RPCs has been performed with pure nitrogen. A small part of them has been also tested with the gas mixture Ar/C2H2F4/i-C4H10 /SF6=75.4/20/4/0.6

Analysis of the performance of the MONOLITH prototype

Abstract In the framework of the study for a large magnetic detector suitable for the physics at a neutrino factory, the data collected with the MONOLITH prototype at the T7-PS facility at CERN has been analyzed. The hadron shower angular resolution for pions followed a 10.4/ E( GeV ) +10.1/E law for orthogonally incident particles. For a baseline of 732 km , this performance would allow the rejection of wrong sign muon background at the level of 10−6, and a capability to measure sin θ 13 down to 10−3. A preliminary analysis of about 106 downward going muons collected at LNGS is also presented. The readout system upgrade allowed the monitoring of each glass RPC with a granularity of 1 cm 2 .

Ageing measurements on glass RPCs

Resistive plate chambers (RPC) are widely used as active elements in particle physics detectors. A deterioration of RPC performance with time has been observed in several experiments, after operation at high temperature or with water contamination in the gas mixture, both for detectors with bakelite electrodes and for the ones with float-glass electrodes. We have developed a kind of RPCs suitable for large scale industrial production. Float-glass is employed as electrode material, and the screen-printing technique is used to apply the resistive coating on the electrodes. A dedicated intensive measurement program on these detectors has been carried out, to assess their long-term behavior and aging properties under different operational conditions.

Performance of a test prototype for MONOLITH

Massive Observatory for Neutrino Oscillation or Limits on Their existence (MONOLITH) is the project of an experiment to study atmospheric neutrino oscillations with a massive magnetized iron detector. A 8 t prototype equipped with about 20 m 2 ofGlass RPCs has been realized and tested at LNGS with cosmic-ray muons. The capability to determine the muon direction, by means ofthe time-of-flight technique, is discussed. # 2001 Elsevier Science B.V. All rights reserved.

A modular design for glass spark counters

Abstract In this paper a fully redesigned glass spark counter is described. The detector exhibits noiseless operation and a time resolution less than 1 ns. The performance makes this detector a good candidate for large area cosmic ray experiments. The simple assembling procedure allows large sensitive area at low cost.

Performance of the readout system for MONOLITH

Abstract In this paper, we describe the performance of the readout system for MONOLITH developed at the LNGS. This system is based on the use of flat cables as readout elements, instead of the conventional copper strips. The advantages of flat cable strips are the good performance, the easy installation and the possibility to realize complex readout systems. The X -coordinate readout system (X-system) is composed by 15 m long, Flat Cable Strips (FCS). The distribution of the time difference between the streamer signals transmitted at both the ends of the X-system FCS has a sigma resolution of the order of 100 ps . This resolution allows the measurement of the particle direction by means of the time-of-flight technique and can be exploited to measure the Y -coordinate with a resolution in the order of 1 cm . The Y -coordinate system is composed by short FCS connected together by a flat cable acting as a bus line. It allows the installation of the electronics outside the apparatus minimizing the number of channels.

The EEE Project: cosmic rays, multigap resistive plate chambers and high school students

The Extreme Energy Events Project has been designed to join the scientific interest of a cosmic rays physics experiment with the enormous didactic potentiality deriving from letting it be carried out by high school students and teachers. After the initial phase, the experiment is starting to take data continuously, and the first interesting physics results have been obtained, demonstrating the validity of the idea of running a real physics investigation in these peculiar conditions. Here an overview of its structure and status is presented, together with some studies about detector performance and first physics results.

Performance of glass RPC with industrial silk-screen-printed electrodes

In this paper we describe the performance of several Glass RPCs, where the water-based graphite coating is replaced by a synthetic coating applied using the screen printing technique. As expected, the performance of the detectors is good and reproducible due to the accurate control of the coating resistivity value. The resistance of the coating to the action of mechanical and chemical agents permits an easy electrode cleaning and mounting with respect to the RPC coated with the graphite varnish. This coating, together with the use of float glass as electrode material, allows an industrial production, where the detector characteristics can be tailored as a function of the experiment requirements.