Two-Phase Hydrogen Density Measurements by Neutron Attenuation

A desirable characteristic of a two-phase hydrogen density measurement by neutron attenuation is its ability to respond dynamically to a transient flow situation. Thickness measurements of a polyethylene mockup of liquid hydrogen indicate that with the use of intense compact Po-Be neutron sources in conjunction with an optimum moderator beam source arrangement, good dynamic measurements can be made. The equipment can be mobile and flexible, and is adaptable for measuring the full range of hydrogen mixtures from liquid to gas in pipes up to 2 inches in diameter.