$B\rho$-defined isochronous mass spectrometry: a new approach for high-precision mass measurements of short-lived nuclei

TL;DR

This paper introduces a new high-precision mass spectrometry technique, $B ho$-IMS, that improves measurement accuracy for short-lived exotic nuclei, demonstrated by precise mass determinations of specific neutron-deficient nuclides.

Contribution

The paper presents the $B ho$-defined IMS method, a novel approach that enhances efficiency, sensitivity, and accuracy in mass measurements of short-lived nuclei.

Findings

Measured masses of $^{46}$Cr, $^{50}$Fe, and $^{54}$Ni with uncertainties of 5-6×10^{-8}

Improved data for testing the unitarity of the CKM matrix

Demonstrated suitability for measuring the most short-lived nuclides

Abstract

A novel technique for broadband high-precision mass measurements of short-lived exotic nuclides is reported. It is based on the isochronous mass spectrometry (IMS) and realizes simultaneous determinations of revolution time and velocity of short-lived stored ions at the cooler storage ring CSRe in Lanzhou. The new technique, named as the $B\rho$-defined IMS or $B\rho$-IMS, boosts the efficiency, sensitivity, and accuracy of mass measurements, and is applied here to measure masses of neutron-deficient $fp$-shell nuclides. In a single accelerator setting, masses of $^{46}$Cr, $^{50}$Fe and $^{54}$Ni are determined with relative uncertainties of (5~-~6)$\times10^{-8}$, thereby improving the input data for testing the unitarity of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. This is the technique of choice for future high-precision measurements of the most rarely produced shortest-lived nuclides.