An X-ray detector records pulses in

PHYSICS · Multi-part · Fermi University Physics · Scientific Practice & Experimental Methods · Uncertainty in measurement · Uncertainty in measurement

Measurement and Method, Ch Counting experiments: Poisson statistics and the root-n rule

Problem

An X-ray detector records n=90 000n = 90\,000 pulses in t=100 st = 100\ \mathrm{s}. The pulses are independent detection events, and the counter has a dead time τd=20 μs\tau_{\rm d} = 20\ \mathrm{\mu s}. ((a)) Find the recorded rate m=n/tm = n/t and its uncertainty u(m)u(m). ((b)) Apply the dead-time correction R=m/(1−mτd)R = m/(1-m\tau_{\rm d}) to get the true rate, and decide whether the correction matters next to u(m)u(m).

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