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.

Why 200 TeV.- Calorimetry.- A Totally Active Liquid Xenon or Kripton Electromagnetic Calorimeter for High Luminosity Hadron Colliders.- Progress on BaF2 Calorimeters.- A New Scintillator: LiBaF3, and Its Basic Properties.- Hybrid Photodiode Tube.- Calorimeters Sampled with Warm Liquids.- Electron Identification with TRD at Future Colliders.- Trigger and Data Acquisition Prospects for the Spaghetti Calorimeter.- Subnuclear Multichannel Integrated Detector Technologies.- Development of Front End Electronics for Future Supercollider Experiments.- Large Area Devices.- A Study of a Toroidal Muon Spectrometer with a Discrete Air Coil for a Multi-TeV Hadron-Hadron Collider.- Latest Results on the Development of the Gaseous Pixel Chamber.- The Muon Spectrometer: What is Needed?.- High Precision Tracking.- Scintillating Fibres for Central Tracking of Charged Particles.- Opto-electronic Delay for the Readout of Particle Tracks from Scintillating Fibres.- GaAs Detectors for Physics at the LHC.- New Developments in Gaseous Tracking Chambers.- Superconducting Strips for Microvertex Detectors.- Leading Particle Detection.- Status of Leading Particle Detection.- Supercollider Physics.- QCD Physics of Jets in the TeV Range.- Higher-order Corrections in QCD Event Simulation.- High Energy Phenomenon of Baryon Number Violation.- Monte Carlo Simulation.- A "Super Monte Carlo" for Multi-TeV Physics Simulation.- Computing Tools, Now and then.- Detector Simulation for Complex Multi-TeV Experiments.- Data Acquisition and Analysis.- Image Processing at Supercolliders.- Signal Processing, Triggering and Data Acquisition.- Participants.