Operational performance of the SNS LLRF interim system

A new approach has been taken to develop and build the Low-Level RF Control System for the SNS Front End and Linear Accelerators, as reported in a separate paper in this conference. An interim version, based on the proven LBNL MEBT design, was constructed to support short-term goals and early commissioning of the Front End RFQ and DTL accelerators, while the final system is under development. Additional units of the interim system are in use at JLab and LANL for concept testing, code development, and commissioning of SNS SRF cryomodules. The conceptual design of the MEBT system had already been presented elsewhere, and this paper will address operational experiences and performance measurements with the existing interim system hardware, including commissioning results at the SNS site for the Front End and DTL Tank 3 together with operational results from the JLab test stand.

Introduction

The LLRF hardware, firmware, and software described here all involve evolutionary changes from the SNS MEBT design[3]. The hardware in particular was modified to be simpler, easier to assemble, and more rugged and reliable in the field. The 19” rack-mount chassis changed from deep to (14”) deep.