Neutron generator tube having a high voltage insulator extending in a non-bounding relationship with an accelerating gap

摘要

A neutron generator tube for borehole logging is disclosed comprising an ion source 21 to provide a source of hydrogen isotope ions, a means 22 to store and control the pressure of hydrogen isotopes atoms associated with the ion source 21, a target assembly 24 for producing neutron bombardment by the hydrogen isotope ions, an ion accelerating gap 30 with an ion travel directing lens defined by two or more electrodes 23,26 selectively connected to one of the ion source 21 and the target assembly 24, and a high voltage insulator 27 associated with the ion source 21 and the target assembly 24 in a non-bounding relationship with the acceleration gap 30. The disclosed arrangement may be suited to provide reduced internal voltage gradients, an increased tube lifetime, a substantially monoenergetic neutron flux on the generator surface, and unchanging ion optics characteristics.