A heavily shielded background monitor records counts in a run lasting (one hour)

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

A heavily shielded background monitor records n=0n = 0 counts in a run lasting t=3600 st = 3600\ \mathrm{s} (one hour). The tabulated 90 %90\ \% upper limit for an observed count of zero is 2.32.3 counts. ((a)) Explain briefly why the root-nn rule cannot be used to assign an uncertainty to this count. ((b)) Report the background rate as an upper limit at 90 %90\ \% confidence.

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