Excitation functions of proton-induced reactions on natural Nd in the 10-30 MeV energy range, and production of radionuclides relevant for double-{\beta} decay

TL;DR

This study measures proton-induced reaction cross sections on natural neodymium in the 10-30 MeV range to assess activation risks for neutrinoless double-beta decay experiments, providing new experimental data where previously limited.

Contribution

The paper provides the first experimental cross section data for proton reactions on natural neodymium in the 10-30 MeV range, relevant for background estimation in double-beta decay experiments.

Findings

Measured excitation functions for multiple radionuclides.

Compared experimental data with TENDL-2010 library predictions.

Identified potential activation products affecting experimental backgrounds.

Abstract

A preferred candidate for neutrinoless double-{\beta} decay, 150Nd, is present in natural neodymium at an abundance level of 5.64%. However, neodymium could be activated by cosmic rays during the period it spends on the Earth's surface. Its activation by protons is therefore of interest when it comes to estimating the possible disturbance effects and increased background during neutrinoless double-{\beta}-decay experiments like Sudbury Neutrino Observatory plus liquid scintillator (SNO+). In most cases, we lack experimental data on proton-induced reactions on neodymium. Therefore, a measurement of cross sections has been performed for the formation of 141Pm, 143Pm, 144Pm, 146Pm, 148Pm, 148Pmm, 149Pm, 150Pm, 140Nd, 141Nd, 147Nd, 149Nd, 138Prm, 139Pr, 142Pr, and 139Ce by 10-30 MeV protons. Oxidation-protected metal foil targets of natural isotopic abundance were irradiated by the usual stacked-foil technique on the external proton beam of the isochronous cyclotron U-120M at the Nuclear Physics Institute at \v{R}e\v{z} near Prague. Special attention was paid to the excitation functions of long-lived radionuclides. The measured data were compared with TENDL-2010 library data (TALYS code).