SNS proton power upgrade requirements for magnet and kicker systems

The Spallation Neutron Source (SNS) Proton Power Upgrade (PPU) will double the beam power from 1.4 to 2.8 MW by adding cavities in the superconducting linear accelerator (SCL) which will increase the beam energy from 0.97 to 1.3 GeV and by increasing the average linac beam current from 26 to 38 mA. Provisions for an accelerator power increase were made in the original SNS project, and these are being leveraged to provide a cost-effective means of doubling the beam power. The magnet systems were originally designed for the higher beam energies except for a few in the injection and extraction regions of the accumulator ring. Three injection region magnets will be redesigned. The eight injection-bump kicker power supplies will be upgraded to permit higher current operation and two additional extraction kicker power supplies and magnets will be added. This paper will review the requirements and options for the magnets and power supplies for the injection and extraction regions.

I. Introduction

The Spallation Neutron Source (SNS) Proton Power Upgrade (PPU) project at Oak Ridge National Laboratory doubles the beam power from 1.4 to 2.8 MW by a combination of increased H- beam current from the Ion Source in the accelerator Front End (FE) and increasing the Linac beam energy in the Superconducting Linac (SCL). The increase in H- beam current to 38 mA, measured at the exit of the radio frequency quadrupole (RFQ), has been demonstrated from the existing ion source [1]. Additional beam current margin will be provided by a planned 2018 operational upgrade to the RFQ prior to PPU. The increased beam energy to 1.3 GeV will be achieved by the addition of 28 superconducting acceleration cavities powered by three identical high voltage converter modulators and 28 klystrons. The design and development of a new modulator for PPU is detailed in a paper presented at this conference [2]. Fig.1 shows the layout of the portion of the SNS accelerator complex to be upgraded during the PPU project. Figure 1.

Layout of SNS accelerator complex