Abstract: Various embodiments include apparatus and methods of using the apparatus having a neutron generator. The neutron generator can include a neutron generator tube having an inner surface and a cylindrical cavity, a field ionization array cylindrically distributed on the inner surface, and a target rod positioned in the cylindrical cavity. Additional apparatus, systems, and methods are disclosed.

Abstract: A neutron generator comprises a cylindrical housing having a target rod concentrically located along a central axis of the cylindrical housing. An array of field ionization nanotips is positioned around an inner surface of the housing, where the array of nanotips extends toward the central axis. A method for logging a formation comprises deploying a logging tool having a neutron generator into a borehole. An array of nanotips is located around an inner cylindrical surface of a cylindrical housing in the neutron generator are energized. An ionizable gas proximate the array of nanotips is ionized. The ions are accelerated radially inward to bombard a titanium layer on an outer diameter of a target rod concentrically located along a central axis of the cylindrical housing to generate neutrons.

Abstract: A neutron generator comprises a cylindrical housing having a target rod concentrically located along a central axis of the cylindrical housing. An array of field ionization nanotips is positioned around an inner surface of the housing, where the array of nanotips extends toward the central axis. A method for logging a formation comprises deploying a logging tool having a neutron generator into a borehole. An array of nanotips is located around an inner cylindrical surface of a cylindrical housing in the neutron generator are energized. An ionizable gas proximate the array of nanotips is ionized. The ions are accelerated radially inward to bombard a titanium layer on an outer diameter of a target rod concentrically located along a central axis of the cylindrical housing to generate neutrons.

Abstract: Sensors are included in an inflatable packer to measure the pressure inside the packer and the distance that the outside wall of the packer moves during inflation. This data is communicated to a control module that monitors and controls the operation of the packer, as well as to a central downhole and/or surface controller.