T. Sakuma

New prototype multi-gap resistive plate chambers with long strips

A new kind of Multi-gap Resistive Plate Chamber (MRPC) has been built for the large-area Muon Telescope Detector (MTD) for the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). These long read-out strip Multi-gap Resistive Plate Chambers (LMRPCs) have an active area of 87.0 � 17.0 cm 2 and ten 250mm-thick gas gaps arranged as a double stack. Each read-out strip is 2.5 cm wide and 90 cm long. The signals are read-out at both ends of each strip. Cosmic ray tests indicate a time resolution of � 70 ps and a detection efficiency of greater than 95%. Beam tests performed at T963 at Fermilab indicate a time resolution of 60–70 ps and a spatial resolution of � 1 cm along the strip direction. & 2008 Elsevier B.V. All rights reserved.

Beam performance of tracking detectors with industrially produced GEM foils

Abstract Three Gas-Electron-Multiplier (GEM) tracking detectors with an active area of 10 cm × 10 cm and a two-dimensional, laser-etched orthogonal strip readout have been tested extensively in particle beams at the Meson Test Beam Facility at Fermilab. These detectors used GEM foils produced by Tech-Etch, Inc. They showed an efficiency in excess of 95% and spatial resolution better than 70 μ m . The influence of the angle of incidence of particles on efficiency and spatial resolution was studied in detail.

Triple GEM detectors for the forward tracker in STAR

Future measurements of the flavor-separated spin structure of the proton via parity-violating W boson production at RHIC require an upgrade of the forward tracking system of the STAR detector. This upgrade will allow the reconstruction of the charge sign of electrons and positrons produced from decaying W bosons. A design based on six large area triple GEM disks using GEM foils produced by Tech-Etch Inc. has emerged as a cost-effective solution to provide the necessary tracking precision. We report first results from a beam test of three test detectors using Tech-Etch produced GEM foils and a laser etched two dimensional strip readout. The detectors show good operational stability, high efficiency and a spacial resolution of around 70 mum or better, exceeding the requirements for the forward tracking upgrade. The influence of the angle of incidence of the particles on the spatial resolution of the detectors has also been studied in detail.

RPC investigation using finely spaced 2-D strip readout

RPCs are in use for many high energy physics applications where there is no need for fine spatial resolution. However, there are applications such as digital calorimetry where the dimension of the induced charge at pick-up pads is of interest. Such calorimetry is proposed for eg, Particle flow calorimetrey at the ILC. While there are both experiments and calculations which address this to some extent, we have been able to read out a single gap RPC using fine pitch laser etched two-dimensional strip readout as used in GEM tracking. This measurement was made in the Fermilab test beam in conjunction with the GEM tracking test for the STAR upgrade. We discuss both data and electrostatic simulations of the signal from a single gap glass RPC.