arXiv subjects

Ágota Koszorús

Publications and source records attributed to Ágota Koszorús.

3 recordsLinked to original sources

arXiv2026

Recent upgrades to the CRIS Decay Spectroscopy Station: Accessing $β$- and $γ$-ray spectroscopy on pure isomeric beams

The Decay Spectroscopy Station (DSS) of the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at ISOLDE-CERN has been upgraded to perform isomer-selective $β$- and $γ$-ray spectroscopy, including a new tape system to perform spectroscopy, free from residual activity. The baseplate of the detection chamber was redesigned to incorporate the tape, a MicroTOF detector for beam diagnostics, and a custom-made, high-vacuum-compatible plastic scintillator. The vacuum operation reached a stable pressure of $10^{-7}$ mbar in the detection chamber, overcoming vacuum issues from the previous design. Around the detection chamber, up to three high-purity germanium (HPGe) detectors and four LaBr detectors can be installed, giving a total photopeak efficiency of the HPGe detectors of 7% at 200 keV. The implementation of a 24-channel digital DAQ system combines the detection array with the CRIS setup to perform laser-assisted $β$- and $γ$-ray spectroscopy. A commissioning experiment with isomeric beams of $^{106g,106m}$In, purified by narrow-band laser resonance ionization, showed complete removal of activity from the $β$ detector and full separation of the ground and isomeric state of $^{106}$In. An average $β$-detection efficiency of 19(2)% was determined from the experiment.

physics.ins-det↗

arXiv2025

A new beamline for Resonant Excitation of Beams with Electromagnetic fields and Lasers (REBEL) and Stopping and Trapping of Radioactive Isotopes for Precision Experiments (STRIPE)

We present two newly constructed experimental setups - REBEL (Resonant Excitation of Beams with Electromagnetic fields and Lasers) and STRIPE (Stopping and Trapping of Radioactive Isotopes for Precision Experiments) - integrated into a single offline beamline at KU Leuven. REBEL is designed for collinear laser spectroscopy of ion bunches following isobaric separation with a multireflection time-of-flight mass spectrometer, enabling high-sensitivity measurements of mass-selected fast-ion beams. In contrast, STRIPE focuses on the deceleration, trapping, and laser cooling of ions in a segmented linear Paul trap, optimized for long interrogation times and precision spectroscopy. The shared infrastructure features stable high-voltage operation ($<10$ ppm), modular vacuum sections, and a fast-beam switchyard to route ions to either experiment. Initial results include a mass-resolving power of $R \approx 12900$ in REBEL and successful ion trapping and laser cooling of ions with a kinetic energy of 10 keV in STRIPE, with improved performance achieved using a frequency-modulated cooling laser. This dual-system platform enables the development and benchmarking of advanced spectroscopy and trapping techniques and is compatible with future operation at radioactive ion beam facilities.

physics.ins-det↗

arXiv2024

High-precision mass measurements of neutron deficient silver isotopes probe the robustness of the $N$ = 50 shell closure

High-precision mass measurements of exotic $^{95-97}$Ag isotopes close to the $N = Z$ line have been conducted with the JYFLTRAP double Penning trap mass spectrometer, with the silver ions produced using the recently commissioned inductively-heated hot cavity catcher laser ion source at the Ion Guide Isotope Separator On-Line facility. The atomic mass of $^{95}$Ag was directly determined for the first time. In addition, the atomic masses of $β$-decaying 2$^+$ and 8$^+$ states in $^{96}$Ag have been identified and measured for the first time, and the precision of the $^{97}$Ag mass has been improved. The newly measured masses, with a precision of $\approx$ 1 keV/c$^2$, have been used to investigate the $N =$ 50 neutron shell closure confirming it to be robust. Empirical shell-gap and pairing energies determined with the new ground-state mass data are compared with the state-of-the-art \textit{ab initio} calculations with various chiral effective field theory Hamiltonians. The precise determination of the excitation energy of the $^{96m}$Ag isomer in particular serves as a benchmark for \textit{ab initio} predictions of nuclear properties beyond the ground state, specifically for odd-odd nuclei situated in proximity to the proton dripline below $^{100}$Sn. In addition, density functional theory (DFT) calculations and configuration-interaction shell-model (CISM) calculations are compared with the experimental results. All theoretical approaches face challenges to reproduce the trend of nuclear ground-state properties in the silver isotopic chain across the $N =$50 neutron shell and toward the proton drip-line.

nucl-ex↗