Measurement of Charge State Distributions using a Scintillation Screen

TL;DR

This paper introduces a novel scintillation screen method combined with Bayesian analysis to measure charge state distributions of heavy ions, providing an alternative to traditional techniques with promising accuracy.

Contribution

The paper presents a new imaging technique using a scintillation screen and CMOS camera for charge state measurement, validated against traditional methods.

Findings

The new method agrees with traditional Faraday cup measurements.

Bayesian analysis effectively quantifies uncertainties.

The technique is viable for charge state distribution measurements.

Abstract

Absolute cross sections measured using electromagnetic devices to separate and detect heavy recoiling ions need to be corrected for charge state fractions. Accurate prediction of charge state distributions using theoretical models is not always a possibility, especially in energy and mass regions where data is sparse. As such, it is often necessary to measure charge state fractions directly. In this paper we present a novel method of using a scintillation screen along with a CMOS camera to image the charge dispersed beam after a set of magnetic dipoles. A measurement of the charge state distribution for 88Sr passing through a natural carbon foil is performed. Using a Bayesian model to extract statistically meaningful uncertainties from these images, we find agreement between the new method and a more traditional method using Faraday cups. Future work is need to better understand systematic uncertainties. Our technique offers a viable method to measure charge state distributions.