An improvement of isochronous mass spectrometry: Velocity measurements using two time-of-flight detectors

TL;DR

This paper proposes an upgraded isochronous mass spectrometry method using two time-of-flight detectors to directly measure ion velocities, aiming to improve mass resolution by correcting momentum spread.

Contribution

It introduces a novel approach combining double TOF detectors with IMS to directly measure ion velocities and reduce momentum spread effects.

Findings

Method effectively corrects momentum spread in IMS.

Potential for significantly improved mass resolution.

Applicable to short-lived exotic nuclei.

Abstract

Isochronous mass spectrometry (IMS) in storage rings is a powerful tool for mass measurements of exotic nuclei with very short half-lives down to several tens of microseconds, using a multicomponent secondary beam separated in-flight without cooling. However, the inevitable momentum spread of secondary ions limits the precision of nuclear masses determined by using IMS. Therefore, the momentum measurement in addition to the revolution period of stored ions is crucial to reduce the influence of the momentum spread on the standard deviation of the revolution period, which would lead to a much improved mass resolving power of IMS. One of the proposals to upgrade IMS is that the velocity of secondary ions could be directly measured by using two time-of-flight (double TOF) detectors installed in a straight section of a storage ring. In this paper, we outline the principle of IMS with double TOF detectors and the method to correct the momentum spread of stored ions.