35.1.Introduction
Non-accelerator experiments have become increasingly important in particle physics.These include classical cosmic ray experiments,neutrino oscillation measurements,and searches for double-beta decay,dark matter candidates,and magnetic monopoles.The experimental methods are sometimes those familiar at accelerators (plastic scintillators,drift chambers,TRD's,etc.) but there is also instrumentation either not found at accelerators or applied in a radically different way.Examples are atmospheric scintillation detectors (Fly's Eye),massive Cherenkov detectors (Super-Kamiokande,IceCube),ultracold solid state detectors (CDMS).And,except for the cosmic ray detectors,radiologically ultra-pure materials are required.