Commissioning of a compact multibend achromat lattice: A new 3 GeV synchrotron radiation facility

TL;DR

NanoTerasu is a newly commissioned 3 GeV synchrotron light source in Japan, featuring a compact four-bend achromat lattice, innovative technologies, and successful initial user operation providing high-brilliance X-ray radiation.

Contribution

This paper details the commissioning process, model-based optics correction, and initial operational parameters of NanoTerasu, a novel compact synchrotron radiation facility with advanced lattice design.

Findings

Achieved stable storage ring operation with 160 mA current

Successfully implemented model-consistent ring optics correction

Provided detailed storage ring parameters for future radiation applications

Abstract

NanoTerasu, a new 3 GeV synchrotron light source in Japan, began user operation in April 2024. It provides high-brilliance soft to tender X-rays and covers a wide spectral range from ultraviolet to tender X-rays. Its compact storage ring with a circumference of 349 m is based on a four-bend achromat lattice to provide two straight sections in each cell for insertion devices with a natural horizontal emittance of 1.14 nm rad, which is small enough for soft X-rays users. The NanoTerasu accelerator incorporates several innovative technologies, including a full-energy injector C-band linear accelerator with a length of 110 m, an in-vacuum off-axis injection system, a four-bend achromat with B-Q combined bending magnets, and a TM020 mode accelerating cavity with built-in higher-order-mode dampers in the storage ring. This paper presents the accelerator machine commissioning over a half-year period and our model-consistent ring optics correction. The first user operation with a stored beam current of 160 mA is also reported. We summarize the storage ring parameters obtained from the commissioning. This is helpful for estimating the effective optical properties of synchrotron radiation at NanoTerasu.