Ultra High Precision with a Muon Storage Ring

TL;DR

The paper discusses the construction and performance of a high-precision muon storage ring designed to measure the muon anomalous magnetic moment with unprecedented accuracy, including the magnetic field uniformity and key components.

Contribution

It introduces a superferric 14 m diameter storage ring with advanced magnetic uniformity and specialized components for precise muon g-2 measurements.

Findings

Achieved magnetic field uniformity of ±1 ppm over the muon storage region

Constructed a superferric 14 m diameter storage ring

Developed a superconducting inflector and a fast non-ferric kicker

Abstract

The Muon $(g-2)$ experiment, E821, at the Brookhaven AGS has the goal to measure the muon anomalous magnetic moment to a relative accuracy of $\pm 3.5 \times 10^{-7}$. A superferric 14 m diameter storage ring has been constructed and an averaged magnetic field uniformity over the 90 mm diameter muon storage region of $\pm$ 1 part per million (ppm) has been achieved. A truncated double-cosine superconducting septum magnet (the inflector) was constructed along with a fast non-ferric kicker. The performance of the storage ring, along with the physics results are reviewed.