Study of Muon Pairs and Vector Mesons Produced in High Energy Pb-Pb Interactions

%NA50 %title\\ \\The experiment studies dimuons produced in Pb-Pb and p-A collisions, at nucleon-nucleon c.m. energies of $ \sqrt{s} $ = 18 and 30 GeV respectively. The setup accepts dimuons in a kinematical range roughly defined as $0.1$ < $y_{c.m.}$ < $1.0$ and $M_T$ > $1 GeV/c$, and stands maximal luminosity (5~10$^{7}$~Pb ions and 10$^7$ interactions per burst). The physics includes signals which probe QGP (Quark-Gluon Plasma), namely the $\phi$, J/$\psi$ and $\psi^\prime$ vector mesons and thermal dimuons, and reference signals, namely the (unseparated) $\rho$ and $\omega$ mesons, and Drell-Yan dimuons. The experiment is a continuation, with improved means, of NA38, and expands its study of {\it charmonium suppression} and {\it strangeness enhancement}.\\ \\The muons are measured in the former NA10 spectrometer, which is shielded from the hot target region by a beam stopper and absorber wall. The muons traverse 5~m of BeO and C. The impact parameter is determined by a Zero Degree Calorimeter (Ta with silica fibres). Energy dissipation and particle production are measured by an Electromagnetic Calorimeter (Pb and scintillating fibres) and a Multiplicity Detector (Si strips).\\ \\\\ \\ \\ \\