Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Molecular Physics

Macroscopic production of spin-polarised hydrogen atoms from the IR-excitation and photodissociation of molecular beams

Chrysovalantis S. Kannis, Jaime Suárez, Theodore Peter Rakitzis

Published Sep 17, 2021• 2 citations
Publisher

Abstract

We describe methods for the production of spin-polarised H and D atoms from the IR-excitation and photodissociation of molecular beams of HBr, HI, and NH3 isotopes, including optical excitation schemes with partial hyperfine resolution. We discuss the extent to which the production rates may approach the IR-laser production rates of 1021photonss−1, and how the production rates of conventional methods of ∼1017s−1 may be surpassed significantly.

DOI
10.1080/00268976.2021.1975053

Related papers

Macroscopic production of spin-polarized hydrogen atoms from the IR-excitation and photodissociation of molecular beams

Chrysovalantis S. Kannis, Jaime Suárez, Theodore Peter Rakitzis

We describe methods for the production of spin-polarized H and D atoms from the IR-excitation and photodissociation of molecular beams of HBr, HI, and ${\rm NH_{3}}$ isotopes, including optical excitation schemes with partial hyperfine resolution. We discuss the extent to which the production rates may approach the IR-laser production rates of ${\rm 10^{21}\, photons\, s^{-1}}$, and how the production rates of conventional methods of ${\sim}{\rm 10^{17} \, s^{-1}}$ may be surpassed significantly.

arXiv:2108.06133•Aug 13, 2021•0 citations

Nanosecond control and high-density production of spin-polarized hydrogen atoms

Dimitris Sofikitis, L. Rubio Lago, Andrew J. Alexander +1 more

We demonstrate directly the nanosecond-timescale production of spin-polarized hydrogen (SPH) atoms from photodissociation of thermal HBr molecules, and the spin-state and Doppler-resolved detection using polarized fluorescence at 121.6 nm, without requiring hyperfine resolution. These techniques allow a variety of spin-dependent, nanosecond pump-probe experiments with SPH, which were not previously realizable. The potential of surpassing the SPH densities and production rates of current techniques is discussed.

Europhysics Letters (EPL)•Feb 25, 2008•16 citations

Laser preparation of spin-polarized atoms from molecular photodissociation

L. Rubio Lago, Dimitris Sofikitis, Antonis Koubenakis +1 more

We discuss how nuclear spin can be highly polarized from the transfer of molecular rotational polarization via the hyperfine interaction, and how large atomic electronic polarization can be produced via molecular photodissociation with polarized light. In combination, these two pulsed-laser techniques can be used to produce highly polarized atoms at densities close to the density of the parent molecules. We compare these methods to existing methods for producing polarized atoms and present specific examples.

Physica Scripta•Dec 22, 2005•4 citations

Mesoscopic production of hyperpolarized N 2 15 O and H 2 O via optical excitation

Dimitris Sofikitis, Theodore Peter Rakitzis

We propose laser-based methods for the production of nuclear spin hyperpolarized molecules. Following pulsed, coherent excitation from ground-state molecules in a molecular beam to specific rotational $|J\phantom{\rule{0.16em}{0ex}}{m}_{J}\ensuremath{\rangle}$ states, the resulting hyperfine polarization beating produces desirable nuclear spin ${m}_{I}$ population distributions and ${m}_{I}\ensuremath{-}{m}_{J}$ correlations at specific later times. At this point, selective dissociation can be used to remove undesired spin states, or a strong magnetic field can be applied, which later can be removed adiabatically to transfer the population-enhanced nuclear spin configurations to the desired nuclear spin state. Finally, the polarization beating is stopped, and the molecules are stored by cryogenic trapping. We show how these methods can be used to produce the long-lived singlet state of $^{15}\mathrm{N}_{2}\mathrm{O}$ and ortho ${\mathrm{H}}_{2}\mathrm{O}$, which have been proposed as magnetic tracers. We discuss how large production rates between 1 and $100 \ensuremath{\mu}\mathrm{mol}$/s with singlet-state populations between 35% and 100% can be achieved.

Physical Review A•Sep 10, 2015•4 citations

Production of HD Molecules in Definite Hyperfine Substates

R. Engels, K. Grigoryev, Chrysovalantis S. Kannis +10 more

Polarized atomic beam sources have been in operation for many years to produce either nuclear polarized atomic hydrogen or deuterium beams. In recent experiments, such a source was used to polarize both isotopes independently at the same time. By recombination of the atoms, hydrogen-deuterium molecules with all possible nuclear spin combinations can be created. Those spin isomers are useful for further applications, like precision spectroscopy, as polarized targets for laser-particle acceleration, polarized fuel for fusion reactors, or as an option for future measurements of electric dipole moments.

arXiv:2002.02009•Physical Review Letters•Mar 18, 2020•9 citations

Switched photodissociation: a proposal for the inversion of atomic and molecular species

J. C. White

A technique is proposed for the inversion of atomic and molecular species by utilizing the energy-storage and -transfer properties of laser-induced collisions in conjunction with selective molecular photodissociation-inversion techniques. Examples for H2–HD and Kr–HI collisions are presented, and the feasibility of creating new vacuum-ultraviolet atomic lasers involving the deuterium Lα transition at 1215 Å and the I resonance line at 1583 Å is examined.

Optics Letters•May 1, 1980•7 citations
We describe methods for the production of spin-polarised H and D atoms from the IR-excitation and photodissociation of molecular beams of HBr, HI, and NH3 isotopes, including optical excitation schemes with partial hyperfine resolution. We discuss the extent to which the production rates may approach the IR-laser production rates of 1021photonss−1, and how the production rates of conventional methods of ∼1017s−1 may be surpassed significantly.
We describe methods for the production of spin-polarized H and D atoms from the IR-excitation and photodissociation of molecular beams of HBr, HI, and NH3{\rm NH_{3}}NH3​ isotopes, including optical excitation schemes with partial hyperfine resolution. We discuss the extent to which the production rates may approach the IR-laser production rates of 1021 photons s−1{\rm 10^{21}\, photons\, s^{-1}}1021photonss−1, and how the production rates of conventional methods of ∼1017 s−1{\sim}{\rm 10^{17} \, s^{-1}}∼1017s−1 may be surpassed significantly.
We demonstrate directly the nanosecond-timescale production of spin-polarized hydrogen (SPH) atoms from photodissociation of thermal HBr molecules, and the spin-state and Doppler-resolved detection using polarized fluorescence at 121.6 nm, without requiring hyperfine resolution. These techniques allow a variety of spin-dependent, nanosecond pump-probe experiments with SPH, which were not previously realizable. The potential of surpassing the SPH densities and production rates of current techniques is discussed.
We discuss how nuclear spin can be highly polarized from the transfer of molecular rotational polarization via the hyperfine interaction, and how large atomic electronic polarization can be produced via molecular photodissociation with polarized light. In combination, these two pulsed-laser techniques can be used to produce highly polarized atoms at densities close to the density of the parent molecules. We compare these methods to existing methods for producing polarized atoms and present specific examples.
We propose laser-based methods for the production of nuclear spin hyperpolarized molecules. Following pulsed, coherent excitation from ground-state molecules in a molecular beam to specific rotational $|J\phantom{\rule{0.16em}{0ex}}{m}_{J}\ensuremath{\rangle}$ states, the resulting hyperfine polarization beating produces desirable nuclear spin mI{m}_{I}mI​ population distributions and ${m}_{I}\ensuremath{-}{m}_{J}$ correlations at specific later times. At this point, selective dissociation can be used to remove undesired spin states, or a strong magnetic field can be applied, which later can be removed adiabatically to transfer the population-enhanced nuclear spin configurations to the desired nuclear spin state. Finally, the polarization beating is stopped, and the molecules are stored by cryogenic trapping. We show how these methods can be used to produce the long-lived singlet state of 15N2O^{15}\mathrm{N}_{2}\mathrm{O}15N2​O and ortho H2O{\mathrm{H}}_{2}\mathrm{O}H2​O, which have been proposed as magnetic tracers. We discuss how large production rates between 1 and $100 \ensuremath{\mu}\mathrm{mol}$/s with singlet-state populations between 35% and 100% can be achieved.
Polarized atomic beam sources have been in operation for many years to produce either nuclear polarized atomic hydrogen or deuterium beams. In recent experiments, such a source was used to polarize both isotopes independently at the same time. By recombination of the atoms, hydrogen-deuterium molecules with all possible nuclear spin combinations can be created. Those spin isomers are useful for further applications, like precision spectroscopy, as polarized targets for laser-particle acceleration, polarized fuel for fusion reactors, or as an option for future measurements of electric dipole moments.