Abstract: An integrated circuit chip (IC) is equipped with a device for preventing reverse engineering by monitoring light emissions emitted from transistors and such electrically active devices in a circuit located in the IC. The device emits extraneous randomized light emissions in substantial close proximity to the transistors to hide a pattern of light emissions emitted from the transistors. As one feature, the device can include a source of randomized light emissions in substantial close proximity to the transistors to hide a pattern of the emitted light from the transistors in randomized light emissions emitted by the source. As a second feature, the device can emit the randomized light emissions by randomly delaying an electrical signal that is electrically coupled to the transistors and, in response to the randomly delayed electrical signal, the transistors randomly emitting light emissions thereby hiding a separate pattern of light emission emitted from the transistors.

Abstract: A method and apparatus for nuclear logging, and in particular, neutron porosity logging is presented. In accordance with the present invention, a pair of spaced lithium detectors, preferably Li.sup.6 I crystal or Li.sup.6 doped glass are used to detect neutrons emitted from a borehole formation being logged. In addition, novel data processing is used to strip the gamma-ray peak from the spectrum developed by the lithium detectors.