View source for Physics:Ring imaging cherenkov counter



A large-acceptance detector using photons from Cherenkov radiation for a measurement of the particle velocity [[File:hepb_img80.gif|9x24px]] . Particles pass through a radiator, the radiated photons may be directly collected by (or are focused by a mirror onto) a position-sensitive photon detector. Respectively, these are called ''direct focusing'' or ''mirror-focused'' RICH detectors. For direct focusing, radiators have to be kept thin (e.g. a liquid radiator), to avoid broadening the ring or filling it; however, [[Physics:References#fabj95b|Fabjan95b]] report a use of a similar setup as a threshold counter. The Cherenkov radiation emitted at angle [[File:hepb_img98.gif|7x12px]] is focused onto a ring of radius ''r'' at the detector surface, and [[File:hepb_img80.gif|9x24px]] can be determined by a measurement of ''r''. For photon detection one uses thin photosensitive (an admixture of e.g. triethylamine to the detector gas) proportional or drift chambers, see [[Physics:References#barr91|Barrelet91]].

A detailed treatment of errors in Cherenkov detectors can be found in [[Physics:References#ypsi94|Ypsilantis94]]. An outlook for the future use is given in [[Physics:References#trei96|Treille96]].

For the various currently successful ways of building practical RICH detectors, see [[Physics:References#ekel96|Ekelof96]] or [[Physics:References#ypsi94|Ypsilantis94]], and literature given there. An example is the combined RICH with liquid radiator (unfocused) and gas radiator (mirror-focused) of the DELPHI experiment at LEP (see [[Physics:References#abre96|Abreu96]], [[Physics:References#aarn91|Aarnio91]]):

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[[File:hepb_img568.gif|435x340px]]

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A combined tracking-cum-RICH project, including even identification of particles by energy loss, has been described in [[Physics:References#obri91|O'Brien91]]. For using a RICH as a significant trigger device, see [[Physics:References#baur94|Baur94]].

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[[Category:Particle physics]]
[[Category:Rudolf K. Bock]]
[[Category:Physics]]
[[Category:High energy physics]]

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