PIG TYPE NEGATIVE ION SOURCE FOR NEUTRON GENERATION TUBE

摘要

PROBLEM TO BE SOLVED: To provide a small-sized and highly-reliable neutron generation tube capable of generating neurons strongly and stably for long hours.;SOLUTION: Negative ions generated from this PIG type negative ion source are accelerated, and a target 5 is set to have a positive-polarity high potential, to thereby prevent heavy element ion emission from the target caused by dirt on a Faraday cup 15. The load of an acceleration power source 25 is reduced in order not to accelerate molecular ions of hydrogen, to thereby reduce breakdown caused by a dark current or consumption of the target caused by heavy ion acceleration. In order to remove electrons accelerated simultaneously with the negative ions from the PIG type negative ion source, a pair of dipole magnetic fields having orthogonal magnetic fields or four orthogonal dipole magnets 6 shifted by 90° one by one are disposed on the downstream of the PIG negative ion source, and only the negative ions are accelerated to improve neutron generation efficiency.;COPYRIGHT: (C)2003,JPO