Bonner sphere

[1] The method was first described in 1960 by Rice University's Bramblett, Ewing and Tom W. Bonner[2] and employs thermal neutron detectors embedded in moderating spheres of different sizes.

This detector system utilizes a few channel unfolding techniques to determine the coarse, few group neutron spectrum.

The original detector system was capable of measuring neutrons between thermal energies up to ~20 MeV.

Bonner sphere spectroscopy (BSS) is one of the few methods that provide an accurate measure of the neutron spectrum.

A single Bonner sphere of an appropriate size can be used for dosimetry, as the sensitivity of the detector will approximate the radiation weighting factor across a range of neutron energies.