The dispersion (standard deviation) of the estimator of neutron flux numberby Scatterer Tags: estimating, experimental error, neutron scattering, standard deviation, statistcs 

#1
Dec1212, 04:32 AM

P: 2

Hello people, I think the problem what I have is well known in experimental physics. Hope, somebody can helps me, thanks in advance. Here is:
There is a source of neutrons with a flux of λ neutrons per minute, which you do not know and want to estimate. You open the detector for one minute and it counts N neutrons. The maximum likelihood estimator for λ would be N. Find the dispersion (or standard deviation) of this estimator. What will it be for the limiting case N=0? Looks like Poisson distribution, where λ isn't known. 



#2
Dec1212, 05:32 AM

Sci Advisor
P: 3,372





#3
Dec1212, 05:38 AM

P: 2

Standard deviation in terms of lambda is square root from lambda, but my event is different I think, have you any idea?




#4
Dec1212, 07:27 AM

Sci Advisor
P: 3,372

The dispersion (standard deviation) of the estimator of neutron flux number
I think this is the best you can get with just one measurement. To estimate an empirical variance would require at least two measurements.



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