Pulse neutron generator design update

This paper describes a neutron generator which was developed at the request of Sandia National Laboratories, Albuquerque, New Mexico, for use in the Sandia-developed uranium logging probe. The principal changes that have evolved since the earlier description include: diameter reduced from 603 mm (2.375 in) to 540 mm (2.125 in), neutron tube accelerator voltage increased from about 100 kV to about 125 kV, and controlatron neutron tube replaced by the Zetatron neutron tube (this added electron suppression). The changes were made to increase clearance when used in small diameter boreholes, increase operational life, and improve neutron output. Circuit and construction modifications which accomplished these changes are included in the text