The lifetime of ${\mathrm{Ba}}^{+}$ ions confined in a Paul trap is found, under typical conditions, to be limited by chemical reactions with residual background gas. An integrated ion-trap and time-of-flight mass spectrometer are used to analyze the reactions of the trapped ${\mathrm{Ba}}^{+}$ ions with three common gases in an ultrahigh vacuum system ( ${\mathrm{H}}_{2}$ , ${\mathrm{CO}}_{2}$ , and ${\mathrm{H}}_{2}\mathrm{O}$ ). It is found that the products of these reactions can all be photodissociated by a single ultraviolet laser at 225 nm, thereby allowing the recovery of the ${\mathrm{Ba}}^{+}$ ions and leading to an increase of the effective trap lifetime. For a Coulomb crystal, the lifetime increased from roughly 6 h to 2 days at room temperature. It is suggested that higher enhancement factors are possible in systems with stronger traps. In addition, photodissociation wavelengths for other common trapped-ion systems are provided.The lifetime of ${\mathrm{Ba}}^{+}$ ions confined in a Paul trap is found, under typical conditions, to be limited by chemical reactions with residual background gas. An integrated ion-trap and time-of-flight mass spectrometer are used to analyze the reactions of the trapped ${\mathrm{Ba}}^{+}$ ions with three common gases in an ultrahigh vacuum system (${\mathrm{H}}_{2}$, ${\mathrm{CO}}_{2}$, and ${\mathrm{H}}_{2}\mathrm{O}$). It is found that the products of these reactions can all be photodissociated by a single ultraviolet laser at 225 nm, thereby allowing the recovery of the ${\mathrm{Ba}}^{+}$ ions and leading to an increase of the effective trap lifetime. For a Coulomb crystal, the lifetime increased from roughly 6 h to 2 days at room temperature. It is suggested that higher enhancement factors are possible in systems with stronger traps. In addition, photodissociation wavelengths for other common trapped-ion systems are provided.

arXiv:2109.05174Physical Review ADec 3, 20219 citations

Trapped Ion Spectroscopy

Frank Schlawin

Springer thesesSep 10, 20163 citations

An ion trap source of cold atomic hydrogen via photodissociation of the BaH+ molecular ion

Stephen A. Jones

Abstract I present a novel scheme for producing cold (magnetically trappable) atomic hydrogen, based on threshold photodissociation of the BaH+ molecular ion. BaH+ can be sympathetically cooled using laser cooled Ba+ in an ion trap, before it is photodissociated on the single photon A1Σ+ ← X1Σ+ transition. The small mass ratio between Ba+ and BaH+ ensures a strong overlap within the ion trap for sympathetic cooling, while the large mass ratio between BaH+ and H means that the released hydrogen can be up to 139 times colder than the parent molecular ions. I examine the hydrogen production rate, and describe how the trap dynamics and photodissociation laser detuning influence the achievable energies. The low infrastructure costs and the ion trap nature of the scheme make it suitable for loading hydrogen into an antihydrogen experiment. This would support a direct matter–antimatter comparison, which could provide important clues as to why our Universe contains so little antimatter.Abstract I present a novel scheme for producing cold (magnetically trappable) atomic hydrogen, based on threshold photodissociation of the BaH+ molecular ion. BaH+ can be sympathetically cooled using laser cooled Ba+ in an ion trap, before it is photodissociated on the single photon A1Σ+ ← X1Σ+ transition. The small mass ratio between Ba+ and BaH+ ensures a strong overlap within the ion trap for sympathetic cooling, while the large mass ratio between BaH+ and H means that the released hydrogen can be up to 139 times colder than the parent molecular ions. I examine the hydrogen production rate, and describe how the trap dynamics and photodissociation laser detuning influence the achievable energies. The low infrastructure costs and the ion trap nature of the scheme make it suitable for loading hydrogen into an antihydrogen experiment. This would support a direct matter–antimatter comparison, which could provide important clues as to why our Universe contains so little antimatter.

New Journal of PhysicsJan 26, 20229 citations

Spectroscopy of Trapped Ions

Richard Claude Thompson

Advances in atomic, molecular, and optical physicsJan 1, 199363 citations

Coherent effects of photodissociation of molecules

Horia I. Metiu

Annual Meeting Optical Society of AmericaJan 1, 19930 citations

The lifetime of

{\mathrm{Ba}}^{+}

ions confined in a Paul trap is found, under typical conditions, to be limited by chemical reactions with residual background gas. An integrated ion-trap and time-of-flight mass spectrometer are used to analyze the reactions of the trapped

{\mathrm{Ba}}^{+}

ions with three common gases in an ultrahigh vacuum system (

{\mathrm{H}}_{2}

{\mathrm{CO}}_{2}

, and

{\mathrm{H}}_{2}\mathrm{O}

). It is found that the products of these reactions can all be photodissociated by a single ultraviolet laser at 225 nm, thereby allowing the recovery of the

{\mathrm{Ba}}^{+}

ions and leading to an increase of the effective trap lifetime. For a Coulomb crystal, the lifetime increased from roughly 6 h to 2 days at room temperature. It is suggested that higher enhancement factors are possible in systems with stronger traps. In addition, photodissociation wavelengths for other common trapped-ion systems are provided.