The in-gas-jet laser ion source: resonance ionization spectroscopy of radioactive atoms in supersonic gas jets

TL;DR

This paper introduces a new method for resonance ionization spectroscopy of radioactive atoms in supersonic gas jets, significantly improving spectral resolution and enabling high-precision measurements in cold, low-density environments.

Contribution

It extends the In-Gas Laser Ionization and Spectroscopy (IGLIS) technique to supersonic jets, achieving tenfold spectral resolution enhancement and demonstrating initial high-resolution spectroscopy results.

Findings

Spectral resolution increased by an order of magnitude.

Successful high-resolution spectroscopy of copper isotope.

Analysis of jet properties for reducing spectral line broadening.

Abstract

New approaches to perform efficient and selective step-wise Resonance Ionization Spectroscopy (RIS) of radioactive atoms in different types of supersonic gas jets are proposed. This novel application results in a major expansion of the In-Gas Laser Ionization and Spectroscopy (IGLIS) method developed at KU Leuven. Implementation of resonance ionization in the supersonic gas jet allows to increase the spectral resolution by one order of magnitude in comparison with the currently performed in-gas-cell ionization spectroscopy. Properties of supersonic beams, obtained from the de Laval-, the spike-, and the free jet nozzles that are important for the reduction of the spectral line broadening mechanisms in cold and low density environments are discussed. Requirements for the laser radiation and for the vacuum pumping system are also examined. Finally, first results of high-resolution spectroscopy in the supersonic free jet are presented for the 327.4 nm 3d^{10}4s^{2}S_{1/2} \rightarrow 3d^{10}4p^{2}P_{1/2} transition in the stable 63Cu isotope using an amplified single mode laser radiation.