The feasibility of a next generation underground water Cherenkov detector is examined and a conceptual design (UNO) is presented. The design has a linear detector configuration with a total volume of 650 kton which is 13 times the total volume of the Super-Kamiokande detector. It corresponds to a 20 times increase in fiducial volume for physics analyses. The physics goals of UNO are to increase...

Suitably designed optical fibers are shown to offer a powerful tool for functional brain mapping, facilitating the detection of Cherenkov radiation generated by relativistic positrons from positron-emitting radionuclides. Fiber probes support a low-loss delivery of the high-intensity short-wavelength part of the Cherenkov spectrum, which is strongly absorbed by biotissues, and lower the thresho...

The window of TeV Gamma-Ray Astrophysics was opened less than two decades ago, when the Crab Nebula was detected for the first time. After several years of development, the technique used by imaging atmospheric Cherenkov telescopes like HESS, MAGIC or VERITAS, is now allowing to conduct sensitive observations in the TeV regime. Water Cherenkov instruments like Milagro are also providing the fir...

The Pierre Auger Collaboration is constructing the first of two observatories designed to solve the mystery of the ultra high energy cosmic rays. Each observatory will consist of an array of 1600 water Cherenkov detectors spread on a surface of 3000km. The main part of these detectors is a polyethylene tank filled up with water and with three photomultipliers on the top. Tyvek will be used as t...

Reversed Cherenkov radiation is the exotic electromagnetic radiation that is emitted in the opposite direction of moving charged particles in a left-handed material. Reversed Cherenkov radiation has not previously been observed, mainly due to the absence of both suitable all-metal left-handed materials for beam transport and suitable couplers for extracting the reversed Cherenkov radiation sign...

An electron beam passing through a metamaterial structure is predicted to generate reversed Cherenkov radiation, an unusual and potentially very useful property. We present an experimental test of this phenomenon using an intense electron beam passing through a metamaterial loaded waveguide. Power levels of up to 5 MW are observed in backward wave modes at a frequency of 2.40 GHz using a one mi...