International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators
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AT/RD-02 Utilization of Variable Energy Radio-Frequency Quadrupole Linear Accelerator Systems C.B. Franklyn Necsa, Pretoria, South Africa Corresponding Author: chris.franklyn@necsa.co.za Radio-frequency quadrupole (RFQ) accelerators are utilized worldwide in a variety of applications but invariably are restricted in their individual diversity due to fixed energy and ion-species constraints. In collaboration with industry Necsa has been developing systems utilizing RFQ accelerators in such a way as to provide for greater diversification of applications. A major development has been the routine operation of combining two RFQs in tandem and using the extracted beam to generate intense, pseudo mono-energetic, neutron beams with energies ranging from 3 to 8 MeV and energy spread of less than 600 keV. Such neutron beams are extremely useful when performing studies of materials with elements exhibiting resonance reactions in the applicable neutron energy range. The greatest challenge in developing the neutron source has been the beam target. The only viable nuclear reaction to use for generating mono-energetic neutrons, in the 3 -10 MeV regime, is the d(d, n)3He reaction. This necessitates the use of a gas target and the challenge then is how to inject an intense ion beam from the accelerator high vacuum environment into the gas target, with minimal ion beam energy degradation. Two types of pseudo-differential pumping systems have recently been developed and their performance under various conditions will be presented. With the systems in operation at Necsa a selected cluster of applications is being developed in collaboration with academia and international partners, so as to create a sustainable research and development environment having identifiable socio-economic impact.
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