Precision Spectroscopy of Fast, Hot Exotic Isotopes for Nuclear Structure
ORAL
Abstract
Collinear resonant ionization laser spectroscopy has been for a long time an important tool for studying the properties of short-lived nuclei away from stability such as nuclear spins, electromagnetic moments and changes in the nuclear root-mean-square charge radii. In order to achieve high efficiency and precision, the ion beams used for such studies are often cooled down and bunched in gas filled radio-frequency ion traps. However, this approach is unsuitable for many species of interest, such as highly reactive ones or those with lifetime shorter (<5 ms) than the trapping time. In this contribution, I will present the developments of a highly sensitive experimental scheme to enable high-precision laser spectroscopy studies of such short-lived isotopes, produced in hot environments, without the need for cooling techniques.
The key idea is based on performing a stepwise resonant ionization process, inside an electric field and with the ionization step laser in a direction perpendicular to the trajectory of the atomic beam. This will allow a very localized interaction region (<5 mm diameter) from which the electrons can be extracted and detected. Thus, an electron-ion coincidence can be achieved, which will substantially reduce the measurements background, while allowing the time and position information of the resulting ions and electrons to be extracted. A Doppler correction can then be applied to the atoms on an event-by-event basis, facilitating precise measurements of the transitions of interests, regardless of the initial energy distribution and spread of the initial beam. With our proposed method we will be able to study, with high precision and sensitivity, the nuclear properties of very short-lived isotopes and isomers (lifetimes < 1 ms) produced in very small amounts (< 1 ion/s), which can’t be investigated spectroscopically with existing experimental methods. The current status of the proposed experiment, preliminary results obtained on stable isotopes, as well as future research directions will be discussed.
The key idea is based on performing a stepwise resonant ionization process, inside an electric field and with the ionization step laser in a direction perpendicular to the trajectory of the atomic beam. This will allow a very localized interaction region (<5 mm diameter) from which the electrons can be extracted and detected. Thus, an electron-ion coincidence can be achieved, which will substantially reduce the measurements background, while allowing the time and position information of the resulting ions and electrons to be extracted. A Doppler correction can then be applied to the atoms on an event-by-event basis, facilitating precise measurements of the transitions of interests, regardless of the initial energy distribution and spread of the initial beam. With our proposed method we will be able to study, with high precision and sensitivity, the nuclear properties of very short-lived isotopes and isomers (lifetimes < 1 ms) produced in very small amounts (< 1 ion/s), which can’t be investigated spectroscopically with existing experimental methods. The current status of the proposed experiment, preliminary results obtained on stable isotopes, as well as future research directions will be discussed.
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Publication: https://arxiv.org/abs/2304.13120
Presenters
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Silviu M Udrescu
Massachusetts Institute of Technology, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
Authors
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Silviu M Udrescu
Massachusetts Institute of Technology, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02142, USA