arXiv:2410.02876 · Review of Scientific Instruments

Room temperature buffer gas beam of metastable state titanium atoms

Jackson Schrott, Scott Eustice, Dan Stamper-Kurn

Published Apr 1, 2025• 1 citation

Abstract

We produce beams of neutral titanium (Ti) atoms in their metastable 3d3(F4)4sa5F5 state by laser ablation into He, N2, and Ar buffer gases. The high temperatures associated with the ablation process populate the a5F5 level without the need for optical pumping. Remarkably, we observe that Ti atoms in the a5F5 state survive thousands of collisions with He and Ar buffer gas atoms without being quenched to lower-energy states. We study the yield of Ti atoms when ablated into buffer gases of varying species and pressure, quantify quenching rates and diffusion cross sections based on simple models, and provide insight into optimal design parameters for an ablation cell. Using a 3.3 cm ablation cell with interchangeable exit apertures, we produce metastable atom beams and quantify their brilliance and velocity distributions as functions of buffer gas pressure.

DOI: 10.1063/5.0243223

Related papers

An atomic beam of titanium for ultracold atom experiments

Jackson Schrott, Diego Novoa, Scott Eustice +1 more

arXiv:2406.07779Review of Scientific InstrumentsNov 1, 20245 citations

High-Flux Beam Source for Cold, Slow Atoms or Molecules

Stephen Maxwell, Nathan Brahms, Robert deCarvalho +7 more

arXiv:physics/0508100Physical Review LettersOct 17, 2005192 citations

A general cold atomic and molecular beam source

Stephen Maxwell, Nathaniel Brahms, Robert deCarvalho +5 more

Bulletin of the American Physical SocietyMay 20, 20050 citations

Slow molecular beams from a cryogenic buffer gas source

A. D. White, S. Popa, Jorge Mellado Muñoz +4 more

arXiv:2408.01862Physical Review ResearchDec 3, 20247 citations

Optical production of metastable krypton

Linda Young, Donghai Yang, R. W. Dunford

Journal of Physics B Atomic Molecular and Optical PhysicsJun 25, 200227 citations

Diffusion of barium atoms in the 6s5d 3 DJ metastable levels and the 6 s2 1 S0 ground state through noble-gas perturbers

R. K. Namiotka, E. Ehrlacher, J. Sagle +5 more

Physical Review AJul 1, 199616 citations

arXiv:2410.02876 · Review of Scientific Instruments

Room temperature buffer gas beam of metastable state titanium atoms

Jackson Schrott, Scott Eustice, Dan Stamper-Kurn

Published Apr 1, 2025• 1 citation

arXiv HTML PDF

Abstract

DOI: 10.1063/5.0243223

Related papers

An atomic beam of titanium for ultracold atom experiments

Jackson Schrott, Diego Novoa, Scott Eustice +1 more

We generate an atomic beam of titanium (Ti) using a "Ti-ball" Ti-sublimation pump, which is a common getter pump used in ultrahigh vacuum systems. We show that the sublimated atomic beam can be optically pumped into the metastable 3d3(4F)4s a5F5 state, which is the lower energy level in a cycling optical transition that can be used for laser cooling. We measure the atomic density and transverse and longitudinal velocity distributions of the beam through laser fluorescence spectroscopy. We find a metastable atomic flux density of 4.3(2) × 109 s-1 cm-2 with a mean forward velocity of 773(8) m/s at 2.55 cm directly downstream of the center of the Ti-ball. Owing to the details of optical pumping, the beam is highly collimated along the transverse axis parallel to the optical pumping beam and the flux density falls off as 1/r. We discuss how this source can be used to load atoms into a magneto-optical trap.We generate an atomic beam of titanium (Ti) using a "Ti-ball" Ti-sublimation pump, which is a common getter pump used in ultrahigh vacuum systems. We show that the sublimated atomic beam can be optically pumped into the metastable 3d3(4F)4s a5F5 state, which is the lower energy level in a cycling optical transition that can be used for laser cooling. We measure the atomic density and transverse and longitudinal velocity distributions of the beam through laser fluorescence spectroscopy. We find a metastable atomic flux density of 4.3(2) × 109 s-1 cm-2 with a mean forward velocity of 773(8) m/s at 2.55 cm directly downstream of the center of the Ti-ball. Owing to the details of optical pumping, the beam is highly collimated along the transverse axis parallel to the optical pumping beam and the flux density falls off as 1/r. We discuss how this source can be used to load atoms into a magneto-optical trap.

arXiv:2406.07779Review of Scientific InstrumentsNov 1, 20245 citations

High-Flux Beam Source for Cold, Slow Atoms or Molecules

Stephen Maxwell, Nathan Brahms, Robert deCarvalho +7 more

We demonstrate and characterize a high-flux beam source for cold, slow atoms or molecules. The desired species is vaporized using laser ablation, then cooled by thermalization in a cryogenic cell of buffer gas. The beam is formed by particles exiting a hole in the buffer gas cell. We characterize the properties of the beam (flux, forward velocity, temperature) for both an atom (Na) and a molecule (PbO) under varying buffer gas density, and discuss conditions for optimizing these beam parameters. Our source compares favorably to existing techniques of beam formation, for a variety of applications.We demonstrate and characterize a high-flux beam source for cold, slow atoms or molecules. The desired species is vaporized using laser ablation, then cooled by thermalization in a cryogenic cell of buffer gas. The beam is formed by particles exiting a hole in the buffer gas cell. We characterize the properties of the beam (flux, forward velocity, temperature) for both an atom (Na) and a molecule (PbO) under varying buffer gas density, and discuss conditions for optimizing these beam parameters. Our source compares favorably to existing techniques of beam formation, for a variety of applications.

arXiv:physics/0508100Physical Review LettersOct 17, 2005192 citations

A general cold atomic and molecular beam source

Stephen Maxwell, Nathaniel Brahms, Robert deCarvalho +5 more

Bulletin of the American Physical SocietyMay 20, 20050 citations

Slow molecular beams from a cryogenic buffer gas source

A. D. White, S. Popa, Jorge Mellado Muñoz +4 more

We study the properties of a cryogenic buffer gas source that uses a low-temperature two-stage buffer gas cell to produce very slow beams of ytterbium monofluoride molecules. The molecules are produced by laser ablation inside the cell and extracted into a beam by a flow of cold helium. We measure the flux and velocity distribution of the beam as a function of ablation energy, helium flow rate, cell temperature, and the size of the gap between the first and second stages of the cell. We also compare the velocity distributions from one-stage and two-stage cells. The one-stage cell emits a beam with a speed of about 82 m s − 1 and a translational temperature of 0.63 K. The slowest beams are obtained using the two-stage cell at the lowest achievable cell temperature of 1.8 K. This beam has a peak velocity of 56 m s − 1 and a flux of 9 × 10 9 ground-state molecules per steradian per pulse, with a substantial fraction at speeds below 40 m s − 1 . These slow molecules can be decelerated further by radiation pressure slowing and then captured in a magneto-optical trap. Published by the American Physical Society 2024We study the properties of a cryogenic buffer gas source that uses a low-temperature two-stage buffer gas cell to produce very slow beams of ytterbium monofluoride molecules. The molecules are produced by laser ablation inside the cell and extracted into a beam by a flow of cold helium. We measure the flux and velocity distribution of the beam as a function of ablation energy, helium flow rate, cell temperature, and the size of the gap between the first and second stages of the cell. We also compare the velocity distributions from one-stage and two-stage cells. The one-stage cell emits a beam with a speed of about 82 m s − 1 and a translational temperature of 0.63 K. The slowest beams are obtained using the two-stage cell at the lowest achievable cell temperature of 1.8 K. This beam has a peak velocity of 56 m s − 1 and a flux of 9 × 10 9 ground-state molecules per steradian per pulse, with a substantial fraction at speeds below 40 m s − 1 . These slow molecules can be decelerated further by radiation pressure slowing and then captured in a magneto-optical trap. Published by the American Physical Society 2024

arXiv:2408.01862Physical Review ResearchDec 3, 20247 citations

Optical production of metastable krypton

Linda Young, Donghai Yang, R. W. Dunford

We have investigated a new scheme for excitation of the 5s, J = 2 metastable level of Kr (5s[3/2] J = 2 ) which can be readily extended to other rare gases. In the scheme, an ultraviolet (UV) lamp is used to create a population of Kr atoms in the 5s[3/2] J = 1 level in a gas cell. The excited atoms are then pumped to the 5p[3/2] J = 2 level, using 819 nm light from a Ti:sapphire laser, from which they decay to the metastable state with a branching ratio of 77%. We made two striking observations: (1) the laser power required to saturate the second step decreases markedly as a function of gas cell pressure, and (2) the UV photon flux is converted with very high efficiency (≈10%) to metastable atom flux. A Monte Carlo study of the scattering of UV photons in the cell reproduces the trends observed. The understanding achieved points to the design of a higher flux source of metastable atoms.We have investigated a new scheme for excitation of the 5s, J = 2 metastable level of Kr (5s[3/2] J = 2 ) which can be readily extended to other rare gases. In the scheme, an ultraviolet (UV) lamp is used to create a population of Kr atoms in the 5s[3/2] J = 1 level in a gas cell. The excited atoms are then pumped to the 5p[3/2] J = 2 level, using 819 nm light from a Ti:sapphire laser, from which they decay to the metastable state with a branching ratio of 77%. We made two striking observations: (1) the laser power required to saturate the second step decreases markedly as a function of gas cell pressure, and (2) the UV photon flux is converted with very high efficiency (≈10%) to metastable atom flux. A Monte Carlo study of the scattering of UV photons in the cell reproduces the trends observed. The understanding achieved points to the design of a higher flux source of metastable atoms.

Journal of Physics B Atomic Molecular and Optical PhysicsJun 25, 200227 citations

Diffusion of barium atoms in the 6s5d 3 DJ metastable levels and the 6 s2 1 S0 ground state through noble-gas perturbers

R. K. Namiotka, E. Ehrlacher, J. Sagle +5 more

We describe a set of experiments that investigate diffusion of barium 6s5d ${\mathrm{}}^{3}$ ${\mathit{D}}_{\mathit{J}}$ metastable level and 6 ${\mathit{s}}^{2}$ ${\mathrm{}}^{1}$ ${\mathit{S}}_{0}$ ground-state atoms through the noble gases: He, Ne, Ar, Kr, and Xe. The barium metastable levels were populated through optical pumping of the 6 ${\mathit{s}}^{2}$ ${\mathrm{}}^{1}$ ${\mathit{S}}_{0}$ \ensuremath{\rightarrow}6s6p ${\mathrm{}}^{3}$ ${\mathit{P}}_{1}^{\mathit{o}}$ intercombination transition with a pulsed laser, followed by spontaneous or stimulated emission into the 6s5d ${\mathrm{}}^{3}$ ${\mathit{D}}_{1,2}$ levels. Collisional mixing then distributed population throughout the 6s5d ${\mathrm{}}^{3}$ ${\mathit{D}}_{\mathit{J}}$ levels. A weak narrow-band cw laser was tuned to appropriate transitions to probe the spatial distribution of metastable level atoms, as well as the hole created in the ground-state spatial distribution, by the pulsed laser. Time-dependent absorption coefficients were obtained by measuring the transmission of the probe laser at several different pump-probe spatial separations. From these absorption data, spatial number density profiles were mapped out for various times following the firing of the pump laser. These density profiles were used to determine the diffusion coefficient for each state at a particular buffer-gas pressure and temperature. From these pressure- and temperature-dependent diffusion coefficients D, we determined the thermally averaged diffusion cross sections ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s5d ${\mathrm{}}^{3}$ ${\mathit{D}}_{\mathit{J}}$ ) and ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6 ${\mathit{s}}^{2}$ ${\mathrm{}}^{1}$ ${\mathit{S}}_{0}$ ) for the metastable and ground-state atoms diffusing through the noble gases, respectively. We also report values for the scaled standard diffusion coefficients ${\mathit{D}}_{0}$ . Our experimental values of the thermally averaged diffusion cross sections ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s5d ${\mathrm{}}^{3}$ ${\mathit{D}}_{\mathit{J}}$ ) and ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6 ${\mathit{s}}^{2}$ ${\mathrm{}}^{1}$ ${\mathit{S}}_{0}$ ) for the barium-helium system are compared with values calculated from published, theoretical barium-helium potentials and the agreement is excellent. \textcopyright{} 1996 The American Physical Society.We describe a set of experiments that investigate diffusion of barium 6s5d${\mathrm{}}^{3}$${\mathit{D}}_{\mathit{J}}$ metastable level and 6${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$ ground-state atoms through the noble gases: He, Ne, Ar, Kr, and Xe. The barium metastable levels were populated through optical pumping of the 6${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$\ensuremath{\rightarrow}6s6p${\mathrm{}}^{3}$${\mathit{P}}_{1}^{\mathit{o}}$ intercombination transition with a pulsed laser, followed by spontaneous or stimulated emission into the 6s5d${\mathrm{}}^{3}$${\mathit{D}}_{1,2}$ levels. Collisional mixing then distributed population throughout the 6s5d${\mathrm{}}^{3}$${\mathit{D}}_{\mathit{J}}$ levels. A weak narrow-band cw laser was tuned to appropriate transitions to probe the spatial distribution of metastable level atoms, as well as the hole created in the ground-state spatial distribution, by the pulsed laser. Time-dependent absorption coefficients were obtained by measuring the transmission of the probe laser at several different pump-probe spatial separations. From these absorption data, spatial number density profiles were mapped out for various times following the firing of the pump laser. These density profiles were used to determine the diffusion coefficient for each state at a particular buffer-gas pressure and temperature. From these pressure- and temperature-dependent diffusion coefficients D, we determined the thermally averaged diffusion cross sections ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s5d${\mathrm{}}^{3}$${\mathit{D}}_{\mathit{J}}$) and ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$) for the metastable and ground-state atoms diffusing through the noble gases, respectively. We also report values for the scaled standard diffusion coefficients ${\mathit{D}}_{0}$. Our experimental values of the thermally averaged diffusion cross sections ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s5d${\mathrm{}}^{3}$${\mathit{D}}_{\mathit{J}}$) and ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$) for the barium-helium system are compared with values calculated from published, theoretical barium-helium potentials and the agreement is excellent. \textcopyright{} 1996 The American Physical Society.

Physical Review AJul 1, 199616 citations

We describe a set of experiments that investigate diffusion of barium 6s5d

{\mathrm{}}^{3}

{\mathit{D}}_{\mathit{J}}

metastable level and 6

{\mathit{s}}^{2}

{\mathrm{}}^{1}

{\mathit{S}}_{0}

ground-state atoms through the noble gases: He, Ne, Ar, Kr, and Xe. The barium metastable levels were populated through optical pumping of the 6

{\mathit{s}}^{2}

{\mathrm{}}^{1}

{\mathit{S}}_{0}

\ensuremath{\rightarrow}6s6p

{\mathrm{}}^{3}

{\mathit{P}}_{1}^{\mathit{o}}

intercombination transition with a pulsed laser, followed by spontaneous or stimulated emission into the 6s5d

{\mathrm{}}^{3}

{\mathit{D}}_{1,2}

levels. Collisional mixing then distributed population throughout the 6s5d

{\mathrm{}}^{3}

{\mathit{D}}_{\mathit{J}}

levels. A weak narrow-band cw laser was tuned to appropriate transitions to probe the spatial distribution of metastable level atoms, as well as the hole created in the ground-state spatial distribution, by the pulsed laser. Time-dependent absorption coefficients were obtained by measuring the transmission of the probe laser at several different pump-probe spatial separations. From these absorption data, spatial number density profiles were mapped out for various times following the firing of the pump laser. These density profiles were used to determine the diffusion coefficient for each state at a particular buffer-gas pressure and temperature. From these pressure- and temperature-dependent diffusion coefficients D, we determined the thermally averaged diffusion cross sections ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s5d

{\mathrm{}}^{3}

{\mathit{D}}_{\mathit{J}}

) and ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6

{\mathit{s}}^{2}

{\mathrm{}}^{1}

{\mathit{S}}_{0}

) for the metastable and ground-state atoms diffusing through the noble gases, respectively. We also report values for the scaled standard diffusion coefficients

{\mathit{D}}_{0}

. Our experimental values of the thermally averaged diffusion cross sections ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s5d

{\mathrm{}}^{3}

{\mathit{D}}_{\mathit{J}}

) and ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6

{\mathit{s}}^{2}

{\mathrm{}}^{1}

{\mathit{S}}_{0}

) for the barium-helium system are compared with values calculated from published, theoretical barium-helium potentials and the agreement is excellent. \textcopyright{} 1996 The American Physical Society.