The NOMAD experiment at the CERN SPS

The NOMAD experiment is a short base-line search for $\nu_{\mu}\rightarrow \nu_{\tau}$ oscillations in the CERN neutrino beam. The $\nu_{\tau}$'s are searched for through their charged-current interactions followed by the observation of the resulting $\tau^{-}$ through its electronic, muonic or hadronic decays. These decays are recognized using kinematical criteria necessitating the use of a light target which enables the reconstruction of individual particles produced in the neutrino interactions. This paper describes the various components of the NOMAD detector: the target and muon drift chambers, the electromagnetic and hadronic calorimeters, the preshower and transition radiation detectors, and the veto and trigger scintillation counters. The beam and data acquisition system are also described. The quality of the reconstruction of individual particles is demonstrated through the ability of NOMAD to observe K$^0_{\rm s}$'s, $\Lambda^0$'s and $\pi^0$'s. Finally, the observation of $\tau^{-}$ through its electronic decay being one of the most promising channels in the search, the identification of electrons in NOMAD is discussed

Measurement of Light Collection of CMS PbWO4 Crystals: Comparison with the Cristal Monte Carlo Simulation Program and Further Evaluation

The measurement of the signal for light collection limited by the effective area of the present APD detectors has been evaluated using a photomultiplier and co60 source. Comparison of the methods and experimental results for simple geometrical situations has been made with the results of the CRISTAL Monte Carlo program which is also used to evaluate more complicated geometries including evaluation of a wavelength shifter used with an APD as a photodetector