ULTRA-SENSITIVE PARTICLE IDENTIFICATION SYSTEMS BASED UPON ELECTROSTATIC ACCELERATORS

A review is presented of a new ultra-sensitive particle identification technique which uses as one component an electrostatic accelerator. The special advantages of this new technique for very low background measurements include negative ion analysis to minimize scattering, high resolution and transmission (E/q, M/q) mass identification, charge exchange particle identification, kinetic energy and dE dx discrimination. It is pointed out that precision dc systems permit characteristic energy identifying signatures to be imposed on individual particles making possible the elimination of a large class of backgrounds. It is also pointed out that the precision energy signatures possible with electrostatic devices permit the analysis of the fragments derived from dissociated molecular ions and suggests a new method of molecular analysis. The technique has already been used in various laboratories for a search for superheavy elements, quarks, and the long lived isotopes 14C and 36Cl. Sensitivities of ∼1:3 × 1015 for 14C in carbon and 1:1015 for 36Cl in chlorine have already been demonstrated. Several possibilities for extending the technique are discussed. One is to use a rastered, micrometer-diameter cesium microprobe to produce negative ions from points on a surface as a function of position; these ions would then be analyzed by the new technique. A second describes a neutral beam procedure which extends the technique to elements such as the noble gases which do not readily form negative ions. © 1979.