High Resolution Tracking Devices Based on Capillaries Filled with Liquid Scintillator

Abstract

%RD46 %title\\ \\The aim of the project is to develop high resolution tracking devices based on thin glass capillary arrays filled with liquid scintillator. This technique provides high hit densities and a position resolution better than 20 $\mu$m. Further, their radiation hardness makes them superior to other types of tracking devices with comparable performance. Therefore, the technique is attractive for inner tracking in collider experiments, microvertex devices, or active targets for short-lived particle detection. High integration levels in the read-out based on the use of multi-pixel photon detectors and the possibility of optical multiplexing allow to reduce considerably the number of output channels, and, thus, the cost for the detector.\\ \\New optoelectronic devices have been developed and tested: the megapixel Electron Bombarded CCD (EBCCD), a high resolution image-detector having an outstanding capability of single photo-electron detection; the Vacuum Image Pipeline (VIP), a high-speed gateable pipeline with 1 $\mu$s delay, allowing operation in high-rate environments. A large size capillary detector with a readout based on the newly developed EBCCD, was installed and put in operation in front of the CHORUS detector. A neutrino interaction event taken with this prototype is shown in Figure 1.\\ \\During 1997 and 1998 the technique of thin planar capillary layers was developed with the aim of adapting capillary detectors to future HEP experiments. Procedures of capillary assembling, cutting and filling have been studied. Two cosmic ray events recorded in a detector prototype built in summer 1998 are shown in Figure 2.\\ \\During 1999 a new study has been undertaken in collaboration with other teams interested in neutrino physics. The aim of the R\&D is the use of EBCCDs in high performance, low cost per channel, multipixel readout systems for large tracking detectors based on scintillators and w.l.s. fibres