US Patent 10061056 Neutron tool with dual-purpose detector

Various embodiments include apparatus and methods to conduct measurements on a formation using a dual purpose detector. The dual purpose detector can be disposed on a neutron tool in a borehole, where the dual purpose detector operatively detects neutrons and gamma rays in response to the formation being probed using a neutron source of the neutron tool. Porosity of the formation can be determined from data based on the neutrons and gamma rays detected by the dual purpose detector. Additional apparatus, systems, and methods are disclosed.