| 摘要 |
PURPOSE:To obtain a detecting element for simultaneously satisfying conflicting requirements which represent the improvement of energy resolution and the maintenance of counting rate by selecting the thickness of the element as an optimal range determined by the movable distance of a carrier. CONSTITUTION:Energy resolution largely depends on the collecting efficiency of a carrier produced by the incidence of radiation and the collecting efficiency is represented in an expression 1 (lambdae, lambdah: movable distance of electron and electron hole, d: thickness of element, x: the position from negative electrode on which interaction generates). Further, lambdae, lambdah represent lambda=mutauE (mu: drift mobility of carrier in crystal, tau: average life of carrier, E: field strength). Energy dispersion spectra dN/dEVSE represent an expression II (F(x): rate of interaction generated in the range of x to x+dX, F(x)=e<-mux> (mu = absorption coefficient), E: energy, sigma: statistical error and the like at the time of carrier production). In other words an expected detecting element can be obtained by performing the operation for finding the resolution by considering the above relative expressions lambdae, lambdah, mu and (d) as functions.
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