Deuteron-induced reactions on natural Zr from threshold to 50 MeV: production of $^{86}$Y

TL;DR

This study measured excitation functions for deuteron-induced reactions on natural zirconium up to 50 MeV, providing new data for isotope production relevant to PET imaging and comparing results with theoretical models.

Contribution

First-time measurement of 19 excitation functions for deuteron reactions on natural zirconium, including 7 reactions reported for the first time, with improved beam current determination techniques.

Findings

Measured excitation functions for 19 reactions, including 7 new ones.

Compared experimental data with multiple nuclear reaction models.

Calculated physical yields for $^{86}$Y and other isotopes, informing production methods.

Abstract

Two stacks of thin Zr foils were irradiated with 30 and 50 MeV deuterons, respectively, using the Lawrence Berkeley National Laboratory $88$-Inch Cyclotron, to investigate this production pathway for the promising PET tracer $^{86}$Y. Nineteen excitation functions for $^{\text{nat}}$Zr($d$,$x$) reactions were measured over a beam energy range of $6.3$--$47.64$ MeV, where the independent cross sections for $^{\text{nat}}$Zr($d$,$x$)$^{88}$Nb and $^\text{{nat}}$Zr($d$,$x$)$^{86\text{m, g}}$Y were measured for the first time. The well-characterized $^{\text{nat}}$Fe($d$,$x$)$^{56}$Co, $^{\text{nat}}$Ni($d$,$x$)$^{56}$Co, $^{\text{nat}}$Ni($d$,$x$)$^{58}$Co, $^{\text{nat}}$Ni($d$,$x$)$^{61}$Cu, $^{\text{nat}}$Ti($d$,$x$)$^{46}$Sc and $^{\text{nat}}$Ti($d$,$x$)$^{48}$V monitor reactions were used to determine the deuteron beam current throughout the stacks. All cross sections were determined using High Purity Germanium (HPGe) detector $\gamma$-ray spectroscopy. A variance minimization technique was employed to simultaneously constrain the deuteron beam currents with multiple monitor reactions, thus reducing systematic uncertainties. An additional $16$ channels are reported for reactions on the nickel, titanium, and iron monitor foils, leading to a total of $35$ excitation functions, with $7$ reaction channels reported for the first time in this work. The measured excitation functions are compared to calculations provided by the reaction modeling codes $\textsc{TALYS}-2.0$, $\textsc{ALICE}-2020$, $\textsc{CoH}-3.5.3$ and $\textsc{EMPIRE}-3.2.3$, as well as the $\textsc{TENDL}-2023$ data library. The degree of agreement between theory and experiments is discussed. The physical yields for $^{\text{nat}}$Zr($d$,$x$)$^{86}$Y and other yttrium isotopes produced are calculated and compared to other production pathways.