High-efficiency neutron detectors and methods of making same

Apparatus for efficiently detecting neutrons, the apparatus comprising:

• a particle-detecting first substrate having first and second surfaces spaced apart by a region of the substrate;
• a first contact layer disposed on the first surface of the substrate;
• a second contract layer disposed on the second surface of the substrate;
• and
• a first stack of neutron-responsive layers, including a first layer of neutron-responsive material of a first type disposed on the first contact layer and a second layer of neutron-responsive material of a second type different from the first type disposed on the first layer, both of the materials being responsive to neutrons absorbed thereby for releasing ionizing radiation reactive products.

Apparatus for efficiently detecting neutrons, the apparatus comprising:

• a particle-detecting first substrate having first and second surfaces spaced apart by a first region of the first substrate and a first set of cavities extending into the first substrate from the first surface;
• a particle-detecting second substrate stacked on the first substrate and having first and second surfaces spaced apart by a second region of the second substrate and a second set of cavities extending into the second substrate from the first surface of the second substrate;
• and
• neutron-responsive material disposed in the first and second sets of cavities and on the first surfaces of the substrates, the material being responsive to neutrons absorbed thereby for releasing ionizing radiation reaction products, wherein the neutron-responsive material disposed in the first and second sets of cavities increases neutron-detection efficiency by increasing the likelihood that the reaction products will be directed into the first and second substrates, respectively, for increased neutron-detection efficiency.

A method of making a high-efficiency neutron detector, the method comprising:

• providing a particle-detecting substrate having a first surface and a plurality of cavities extending into the substrate from the first surface;
• filling the plurality of cavities with a neutron-responsive material;
• and
• forming a thick film of the neutron-responsive material over the first surface including the plurality of cavities wherein the cavities relieve stress in the thick film to prevent delamination of the thick film from the first surface, the material being responsive to neutrons absorbed thereby for releasing ionizing radiation reaction products, wherein the neutron-responsive material disposed in the cavities at the first surface increases neutron-detection efficiency by increasing the likelihood that the reaction products will be directed into the substrate for increased neutron-detection efficiency.