Which material is Americium-241 often combined with in nuclear gauges to create a neutron source?

Americium-241 is often combined with beryllium in nuclear gauges to create a neutron source due to the unique properties of beryllium. When americium-241 undergoes alpha decay, it emits alpha particles. When these alpha particles interact with beryllium, they initiate a nuclear reaction that generates neutrons. This characteristic makes the americium-241 and beryllium combination a valuable neutron source for various applications, particularly in nuclear density gauges used in construction and geotechnical testing.

This pairing is favored because beryllium is efficient in producing neutrons when bombarded by alpha emissions. The neutron source created in this manner is beneficial for measuring the moisture and density of materials like soil and concrete, as the generated neutrons can penetrate those materials effectively, allowing for accurate readings.