Subsurface penetrometer radiaton sensor probe and system

A penetrometer sensor probe and system with a detachable sleeve section which performs radiation measurements in subsurface formations. The penetrometer sensor probe measures radiation particularly gamma radiation in real time as the sensor probe is retrieved from a subsurface formation following an initial penetrometer push operation. A sacrificial sleeve surrounding the sensor probe's radiation detector is separated from the penetrometer after an initial push operation at a particular subsurface depth. During a retraction process, a sleeve section containing the radiation detector is detached from the sacrificial sleeve of the penetrometer. The sleeve provides both strength to the penetrometer and protects the probe's radiation detector from damage. Additionally, the detachable sleeve results in significantly reduced bremsstrauling scattering radiation attributed to gamma radiation that otherwise would strike a steel casing adjacent to the radiation detector. The penetrometer sensor probe and system allow for a significantly higher signal-to-noise ratio for detecting gamma radiation in subsurface media.