European Nuclear Physics Conference 2025

Towards Precise Reference Quadrupole Moment Measurements in Transition Metals

Not scheduled

1m

Moho

Poster Nuclear Structure, Spectroscopy and Dynamics Poster session

Speaker

Shikha Rathi (Technion – Israel Institute of Technology, Haifa 3200003, Israel)

Description

The spectroscopic quadrupole moment ($Q$) is a fundamental property that provides information about nuclear deformation. However, its precise extraction for the transition elements remains challenging due to their complex atomic structures. Meanwhile, muonic atoms offer a simpler hydrogen-like structure with amplified hyperfine interaction effects. Recent efforts have revived this technique, successfully measuring the $Q$ of $^{185-187}$Re $[1]$. Unfortunately, in the mid-$Z$ region, these measurements remain limited by low detection efficiency $[2]$ or poor resolving power $[3]$.
In this talk, I will present a new approach to measuring the reference $Q$ values of transition elements by combining muonic atom spectroscopy with the high efficiency and resolving power of a cryogenic microcalorimeter (MC) detector $[4]$. I will discuss the associated challenges and feasibility of this measurement based on simulations, using $^{63}$Cu as a test case, along with its detailed theoretical hyperfine interaction calculations using the mcdfgme Dirac-Fock code $[5]$. Our method aims to overcome the current limitations in precision, reducing the uncertainty in $Q$ by up to a factor of 30. An improved reference quadrupole moment will allow the calibration of entire isotopic chains (including isomers and short-lived excited states), offering a deeper understanding of the nuclear structure.

References:
$[1]$ A. Antognini, et al., Physical Review C 101, 054313 (2020)
$[2]$ R. Weber, et al., Nuclear Physics A 377, 361-378 (1982).
$[3]$ B. Effenberger, et al., Zeitschrift für Physik A Atoms and Nuclei 309, 77-81 (1982).
$[4]$ Unger, Daniel, et al., Journal of Low Temperature Physics 120, 344-351 (2024).
$[5]$ Paul Indelicato, Mcdfgme, a Multiconfiguration Dirac Fock and General Matrix Elements Program (Release 2024v2), http://www.lkb.upmc.fr/metrologysimplesystems/mdfgme-a-general-purpose-multiconfiguration-dirac-foc-program/ 2024
$[5]$ N. J. Stone, International Atomic Energy Agency (IAEA) Austria, INDC(NDS)-0833, (2021)