Why 200 TeV (A. Zichichi). Calorimetry: A Totally Active Liquid Xenon or Kripton Electromagnetic Calorimeter for High Luminosity Hadron Colliders (M. Bosteels et al.). Progress on BaF2 Calorimeters (G. Charpak et al.). Subnuclear Multichannel Intergrated Detector Technologies: Development of FrontEnd Electronics for Future Supercolliders Experiments (F. Anghinolfi et al.). Large Area Devices: A Study of a Toroidal Muon Spectrometer with a Discrete Air Coil for a MultiTeV HadronHadron Collider (F. Bergsma et al.). Latest Results on the Development of the Gaseous Pixel Chamber (D. Antreasyan et al.). High Precision Tracking: Optoelectronic Delay for the Readout of Particle Tracks from Scintillating Fibers (T. Gys et al.). GaAs Detectors for Physics at the LHC (S.P. Beaumont et al.). Leading Particle Detection: Status of Leading Particle Detection (G. Anzivino et al.). Supercollider Physics: QCD Physics of Jets in the MultiTeV Range (V.A. Khoze). HigherOrder Corrections in QCD Event Simulation (G. Marchesini). Monte Carlo Simulation: A 'Super Monte Carlo' for MultiTeV Physics Simulation (J. Alberty et al.). Computing Tools, Now and Then (E. Pagiola). 11 additional articles. Index.

The present volume is based on the proceedings of the 12th Workshop of the INFN ELOISATRON Project, held at the "Ettore Majorana" Centre for Scientific Culture (EMCSC), Erice (frapani), Sicily, Italy, in the period September 15-20, 1990. The proceedings deal with the presentation of "New Technologies for Supercolliders". Three new energy frontiers (16,40 and 200 TeV) are now opened up for the future of Subnuclear Physics. Basic problems above the Fermi-energy are crowding up: but no one knows the energy levels needed for their solution. This is why the technology for experiments with the new generation of Supercolliders needs to be pursued having in mind the problems which are of common interest in the three energy frontiers. The primary purpose of the Workshop was to contribute towards the highest energy limit in the search for new instruments and new technologies. Furthermore, the present status and performances of various detector technologies were reviewed. The possible options for a powerful apparatus whose goal would be the discovery of the top, Higgs and SUSY particles in a very high energy, high rate environment, were finally analysed. The Workshop was sponsored by the Italian National Institute for Nuclear Physics (INFN), the Italian Ministry of Education, the Italian Ministry of Scientific and Technological Research and the Sicilian Regional Government. We are thankful to the staff of EMCSC for their efficient and warm support.