Graduate Research at Michigan State University to Push the Intensity Frontier and Support Accelerator Science

Michigan State University, East Lansing MI

Investigators

Abstract

This project will push the frontier in intensity of ion beams produced by superconducting ion accelerators. High accelerator performance requires a bright, continuous source of ions, and for that ion accelerators typically use sources of high-charge-state ions which can be efficiently accelerated. Such sources, called Electron Cyclotron Resonance or ECR sources, are complex with rich physics to be explored. In this project, factors leading to unreliable ECR source operation will be studied. Diagnostics will systematically gather information to better understand, mitigate, and control reliability issues. This research will be carried out at Michigan State University, where it will help to improve performance of existing ion sources. This project will train one PhD graduate student in accelerator physics technology. To maintain a stable and compact beam phase-space for reliable machine operation of continuous wave superconducting radio-frequency (SRF) linacs, ECR sources must continuously inject ion beams with low drifts and stable output. In this project, ECR sources at the National Superconducting Cyclotron Laboratory (NSCL) and the Facility for Rare Isotope Beams (FRIB) will be instrumented to measure correlations of temperature in key system components with the current output. A data logging system will be developed, drift correlations identified, and mitigations will be tested. Fast plasma instabilities are also observed in high intensity ECR operation and can lead to ~25% or more oscillations in beam current with potential machine damage. These instabilities will be studied with the FRIB and NSCL sources using higher-charge-state ions, where understanding of the instability will be improved through analytical studies, development of simple parametric models, and synergetic collaboration with other research groups. The timeline of the project will cover three years and is consistent with early commissioning activities on the FRIB front-end and leverages FRIB hardware.