Target gas loading for neutron generator

A method, comprising:

• operating a neutron generator in a loading mode by:
• ionizing ionizable gas within an ion source of the neutron generator to create a plurality of ions;
• and
• accelerating the plurality of ions by providing a first voltage to a target rod that supports a target of the neutron generator to create a defocused ion beam that bombards the target, wherein the first voltage has a first value ranging from approximately 10 kilovolts (kV) to 50 kV, wherein the defocused ion beam results from an increased number of charge exchange collisions at the first voltage that scatter ion trajectories, and wherein the defocused ion beam is incident on at least 80% of a surface area of the target;
• and
• operating the neutron generator in a generating mode to generate a plurality of neutrons by accelerating the plurality of ions by providing a second voltage to the target rod to create a focused ion beam that bombards the target, wherein the second voltage is greater than the first voltage, wherein the second voltage has a second value ranging from approximately 60 kV and 130 kV, and wherein the focused ion beam is more focused than the defocused ion beam due to reduced charge exchange collisions at the second voltage compared to the first voltage.