Long-lifetime, high-yield, fast neutrons source

A method of manufacturing a neutron generator, the method comprising:

• providing a housing that includes a vacuum chamber and a head unit;
• providing a target rod along a central axis of the neutron generator inside the vacuum chamber of the neutron generator at a first end;
• providing a gas reservoir along the central axis inside the vacuum chamber at a second end opposite the first end;
• providing a planar ion source between the gas reservoir and target rod about the central axis;
• and
• providing a focusing component selected from the group consisting of a focusing electrode coupled to an independent variable power source, a focusing reflective surface, a magnetic field generator, and any combination thereof.

A method of operating a neutron generator for logging information, the method comprising:

• deploying a logging tool having a neutron generator into a borehole;
• wherein the neutron generator comprises:
• a housing;
• a gas reservoir disposed within the housing;
• a target rod disposed within the housing and having a longitudinal axis aligned with a central axis of the housing,
• a target disposed on a surface of the target rod facing the gas reservoir;
• a planar ion source adjacent to the gas reservoir and disposed between the target and the gas reservoir and comprising a planar array of field ionization nano-tips extending perpendicular to and about a central axis of the neutron generator between the gas reservoir and the target rod within the neutron generator;
• and
• a focusing component selected from the group consisting of a focusing electrode coupled to an independent variable power source, a focusing reflective surface, a magnetic field generator, and any combination thereof;
• energizing within the neutron generator, the planar ion source;
• ionizing an ionizable gas proximate the nano-tips creating ions;
• focusing the ions with the focusing component in a direction that is parallel to the central axis of the neutron generator;
• and
• accelerating the ions to bombard the target.