What type of detector is commonly used in a nuclear gauge for measuring thermalized neutrons?

Helium-3 tubes are widely used in nuclear gauges for measuring thermalized neutrons due to their high sensitivity to neutrons specifically in the thermal energy range. In a Helium-3 tube, a thermal neutron interacts with the Helium-3 gas, leading to a nuclear reaction that produces charged particles, which can then be detected as electrical signals. This interaction is fundamental for accurate measurements in applications where neutron detection is crucial, such as in soil density, moisture content analysis, and other materials testing.

The response of Helium-3 to thermalized neutrons makes it particularly suited for applications requiring precision and the ability to detect low levels of neutron radiation. This characteristic sets Helium-3 tubes apart from other types of detectors, which may not possess the same level of effectiveness in detecting thermal neutrons. Other detectors, like Geiger-Mueller tubes for example, are primarily designed for detecting beta and gamma radiation and may not respond effectively to neutrons.