Development and status of the SNS ion source

The ion source for the Spallation Neutron Source (SNS) is a radio-frequency, multicusp source designed to deliver 45 mA of H with a normalized rms emittance of less than 0.2 π mm mrad to the SNS accelerator. The ion source— designed, constructed, and commissioned at Lawrence Berkeley National Laboratory (LBNL)—satisfies the basic requirements of commissioning and early operation of the SNS accelerator. To improve reliability of the ion source and consequently the availability of the SNS accelerator, we are undertaking a comprehensive ion source development program at Oak Ridge National Laboratory (ORNL). To date, this program has focused on design and development of internal and external ion source antennas having long operational lifetimes, development and characterization of efficient RF matching networks, simulation and measurement of the extracted ion beam and, optimization of the beam extraction and Cs systems. This report will outline progress made in some of these areas as well as summarize the current state of the SNS ion source discussing specifically source performance during front end re-commissioning at ORNL.