Measurement of material isotopics and atom number ratio with alpha-particle spectroscopy for the NIFFTE fission Time Projection Chamber actinide target

TL;DR

This paper reports precise measurements of isotopic concentrations and atom number ratios of a double-sided actinide target using alpha-spectroscopy and mass spectrometry, crucial for normalizing fission cross-section ratios in nuclear experiments.

Contribution

It introduces a combined alpha-spectroscopy and mass spectrometry method to accurately determine actinide isotope ratios for nuclear physics applications.

Findings

Pu-239/U-235 atom ratio measured with <1% uncertainty

Validated alpha-spectroscopy and mass spectrometry combination for isotope analysis

Provides normalization data for fission cross-section measurements

Abstract

We present the results of a measurement of isotopic concentrations and atomic number ratio of a double-sided actinide target with alpha-spectroscopy and mass spectrometry. The double-sided actinide target, with primarily Pu-239 on one side and U-235 on the other, was used in the fission Time Projection Chamber (fissionTPC) for a measurement of the neutron-induced fission cross-section ratio between the two isotopes. The measured atomic number ratio is intended to provide an absolute normalization of the measured fission cross-section ratio. The Pu-239/U-235 atom number ratio was measured with a combination of mass spectrometry and alpha-spectroscopy with a planar silicon detector with uncertainties of less than 1%.