The Crisis Detector

The prototype of a charged particle identifier with 1m x 1m acceptance, has been tested at Fermilab using a pion-proton beam at 40 and 100 GeV/c. Its operation is based on the principle of ionization sampling, and the test results indicate that the prototype achieved the 14% FWHM resolution predicted for the distribution of average ionization for 64 samples taken in an 80% Ar -20% CO2 gas mixture. Dependence of the performance on various parameters is discussed.