C. Fanin

The ZEUS barrel and rear muon detector

Abstract Design, construction and performance characteristics of the ZEUS barrel and rear muon detector are presented.

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

The OPERA magnetic spectrometer

The OPERA neutrino oscillation experiment foresees the construction of two magnetized iron spectrometers located after the instrumented lead-nuclear emulsion targets. The spectrometer consists of a dipolar magnet without air gaps. The driving coils are located in the return yokes which are connected by two columns of iron slabs interleaved with Resistive Plate Chambers. The particle trajectories are measured by layers of vertical drift tube planes located before and after the magnet. In this paper we review the construction of the spectrometers. In particular, we describe the results obtained front the magnet and RPC prototypes and the installation of the final apparatus at Gran Sasso. We present the ballistic techniques employed to calibrate the field in the bulk of the magnet and the results in term of field uniformity and magnetic properties of the iron. Moreover, we demonstrate that a field calibration at the level of 3% can be reached and we discuss the limiting systematics. The mass production of RPC started in Jan 2003. Results of the tests and issues concerning the mass production are reported. Finally, the expected physics performance of the detector is described; estimates rely on numerical simulations and the outcome of the tests described above.

Performance of the drift tubes for the barrel muon chambers of the CMS detector at LHC

Abstract The barrel muon chambers of the CMS detector consist of three sets of four layers of rectangular drift tubes. The performance of several prototypes was measured in a muon beam for various experimental conditions. Special emphasis was given to study performance aspects related to the trigger capability of the chambers.

Further studies on a DTBX prototype for the CMS muon detector at LHC

Abstract The performance of a small prototype chamber of the baseline project for the muon barrel detector for CMS has been studied in a muon beam. Its efficiency with different gases and wire diameters, the trigger possibilities and the response in presence of a large number of electromagnetic secondaries associated to the muon are evaluated. The results are compared with a full Monte Carlo simulation.

A scintillator based muon system with SiPM readout for the SuperB detector

The existing muon detectors for high-energy physics experiments are mainly made of gas chambers such as Resistive Plate Chambers, Limited Streamer Tubes or Multi Wire Proportional Chambers. With the increasing luminosity of the new accelerators and the increment in dimensions of the experiments the development of a new detection technique, which is robust, cheap and capable to sustain high particle rate, is mandatory. We present the technology proposed for the Super B muon system. The detector is based on MINOS style extruded scintillators coupled to wavelength shifting fibers. The light readout is done by means of Silicon Photomultiplier devices. We report the R&D results on prototypes that can be operated either with binary readout, measuring only one coordinate, or with a TDC readout that can measure both the coordinate at the same time with adequate precision. Efficiency and time resolution will be discussed for different prototype geometry as well as the main operational issues related to the photodetectors, like stability, noise rate and neutron damage. A full-scale prototype with the same geometry designed for the SuperB experiment is under construction in our lab and it will be tested with a muon/pion beam at FNAL next fall. The structure optimization has been studied using a GEANT4 Monte Carlo simulation and the expected muon identification performances have been evaluated with a neural network algorithm, we present preliminary results of the optimization and its implication for the SuperB muon system.

The BaBaR drift chamber project

The BaBar Drift Chamber is now under construction. We review its design, the progress in the construction of the components, the plan for assembly and stringing and we present test results obtained with a prototype exposed at SLAC to cosmic rays. We also report on projected dE/dx performance from beam tests done with a chamber with a different cell design.

The automated stringing system for the BaBar drift chamber

Abstract After discussing the motivations for the project, the automated equipment used for the BaBar Drift Chamber stringing is described. Details are given mainly concerning the crucial points of setting-up and calibration. The focus is on the high accuracy reached by a large and complex mechanical tool.

The BaBar drift chamber project

The BaBar Drift Chamber is now under construction. We review its design, the progress in the construction of the components, the plan for assembly and stringing and we present test results obtained with a prototype exposed at SLAC to cosmic rays. We also report on projected dE/dx performance from beam tests done with a chamber with a different cell design.