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

Microfabrication Technology

Study on Quasi-monochromatic Metastable Helium Atom Beam Source System

Chen Yuan-pei

Published Jan 1, 2002• 0 citations
OpenAlex

Abstract

A system of metastable helium atom beam source has been developed.Metastable helium atoms are produced by electron exicitation.A atom beam has been formed as the gases of metastable helium atoms pass through the nozzle in constant entropy expansion process.Quasi-monochromatic beam of metastable helium atom has been obtained by selecting the longitudial velocity of the atom beam and eleminating its transversal velocity with laser cooling.

Related papers

Pulsed metastable atomic beam source for time-of-flight applications

Armin KOHLHASE, Shigetomo KITA

A metastable atomic beam source was developed utilizing pulsed helium and argon nozzle beams. A coaxial electron gun, which can be used in a pulsed as well as in a continuous mode, excites the noble gases to their metastable states by electron bombardment in the direction of propagation of the ground-state atoms. In contrast to former work, the electron beam is controlled and accelerated by a combination of three hemispherically shaped tungsten grids. With continuous electron gun operation the source produces a metastable flux of about 1015 atoms/sr s for helium and argon under optimum expansion conditions. Applying short electrical pulses to a control grid yields supersonic metastable atom pulses, with velocity distributions having a relative width as low as 3.8% for helium and 6.5% for argon ( FWHM ) with a 100% modulation of the metastable beams. These features make the source applicable for velocity analyzed scattering experiments using the time-of-flight technique.

Review of Scientific Instruments•Dec 1, 1986•16 citations

A bright metastable atom source at 80 K

Wei-Jian Lu, Maarten D. Hoogerland, Dragana Milic +2 more

We describe a high flux source of cold (80 K) metastable helium atoms. The source employs a direct current nozzle discharge which produces in excess of 1015 atoms/steradian/s. Liquid nitrogen cooling of the discharge source yields atomic velocities below 900 ms−1. Such a source has practical applications for experiments concerned with laser cooling and trapping of metastable helium atoms.

Review of Scientific Instruments•Jun 1, 2001•20 citations

An Intense, Laser-cooled Source Of Metastable Helium Atoms

Wei-Jian Lu, Dragana Milic, R. M. S. Knops +3 more

One of the advantages of atom optics compared with conventional optics is the ability to increase the brightness of an atomic beam relative to the original source. This arises from the use of dissipative light forces to cool the atoms, thereby increasing the atomic phase space density. We describe progress in the development of a system that increases the brightness of a conventional expanding nozzle source to create an intense, collimated beam of metastable helium atoms.

Quantum Electronics and Laser Science Conference•May 18, 1997•0 citations

A high-intensity beam of metastable helium atoms with good velocity resolution

Bernhard Brutschy, Hellmut Haberland

The excitation of a low-energy ground state helium beam to its metastable states by electron impact is analysed. It is shown that the narrowest velocity distribution for the resulting metastable helium beam is obtained by directing the helium and electron beams parallel or antiparallel. A source of metastable helium atoms was constructed according to this analysis which produced a beam of 3*10 14 metastable atoms/s sr with a velocity resolution of 3% FWHM for a room-temperature beam (E=66 meV). A possible source of errors in time-of-flight experiments with metastable atoms is pointed out.

Journal of Physics E Scientific Instruments•Jan 1, 1977•61 citations

Bright metastable helium atomic beam for lithography and atom optics

K. G. H. Baldwin, Wei-Jian Lu, Dragana Milic +3 more

Intense, highly collimated sources of atoms have many potential applications. Bright beams will be important for competitive high flux and high resolution direct-write techniques in lithography, with the added advantage of parallel writing through laser manipulation. Intense sources will also be useful in other atom optic devices e.g. for loading atoms into hollow fiber waveguides. In atomic physics, many collision processes can only be measured with the sensitivity offered by such high flux sources. We report progress on the development of an intense, collimated beam of metastable helium atoms which improves the brightness generated by conventional nozzle discharge sources by several orders of magnitude. The system uses diode lasers to transversely collimate and then to longitudinally slow the atoms, using Zeeman tuning to compensate for the changing Doppler shift. The slowed, collimated beam is then compressed in a 2D magneto-optic trap before a final collimation stage, to achieve the required increase in intensity. Initial experiments using the helium source for some of the applications above are described.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 1, 1997•4 citations

A bright metastable helium atomic beam for lithography and atom optics

Baldwin, KGH, Lu, W, Dragana Milic +3 more

Intense, highly collimated sources of atoms have many potential applications. Bright beams will be important for competitive high flux and high resolution direct-write techniques in lithography, with the added advantage of parallel writing through laser manipulation. Intense sources will also be useful in other atom optic devices e.g. for loading atoms into hollow fiber waveguides. In atomic physics, many collision processes can only be measured with the sensitivity offered by such high flux sources. We report progress on the development of an intense, collimated beam of metastable helium atoms which improves the brightness generated by conventional nozzle discharge sources by several orders of magnitude. The system uses diode lasers to transversely collimate and then to longitudinally slow the atoms, using Zeeman tuning to compensate for the changing Doppler shift. The slowed, collimated beam is then compressed in a 2D magneto-optic trap before a final collimation stage, to achieve the required increase in intensity. Initial experiments using the helium source for some of the applications above are described.

•Jan 1, 1997•0 citations
A system of metastable helium atom beam source has been developed.Metastable helium atoms are produced by electron exicitation.A atom beam has been formed as the gases of metastable helium atoms pass through the nozzle in constant entropy expansion process.Quasi-monochromatic beam of metastable helium atom has been obtained by selecting the longitudial velocity of the atom beam and eleminating its transversal velocity with laser cooling.
A metastable atomic beam source was developed utilizing pulsed helium and argon nozzle beams. A coaxial electron gun, which can be used in a pulsed as well as in a continuous mode, excites the noble gases to their metastable states by electron bombardment in the direction of propagation of the ground-state atoms. In contrast to former work, the electron beam is controlled and accelerated by a combination of three hemispherically shaped tungsten grids. With continuous electron gun operation the source produces a metastable flux of about 1015 atoms/sr s for helium and argon under optimum expansion conditions. Applying short electrical pulses to a control grid yields supersonic metastable atom pulses, with velocity distributions having a relative width as low as 3.8% for helium and 6.5% for argon ( FWHM ) with a 100% modulation of the metastable beams. These features make the source applicable for velocity analyzed scattering experiments using the time-of-flight technique.
The excitation of a low-energy ground state helium beam to its metastable states by electron impact is analysed. It is shown that the narrowest velocity distribution for the resulting metastable helium beam is obtained by directing the helium and electron beams parallel or antiparallel. A source of metastable helium atoms was constructed according to this analysis which produced a beam of 3*10 14 metastable atoms/s sr with a velocity resolution of 3% FWHM for a room-temperature beam (E=66 meV). A possible source of errors in time-of-flight experiments with metastable atoms is pointed out.
Intense, highly collimated sources of atoms have many potential applications. Bright beams will be important for competitive high flux and high resolution direct-write techniques in lithography, with the added advantage of parallel writing through laser manipulation. Intense sources will also be useful in other atom optic devices e.g. for loading atoms into hollow fiber waveguides. In atomic physics, many collision processes can only be measured with the sensitivity offered by such high flux sources. We report progress on the development of an intense, collimated beam of metastable helium atoms which improves the brightness generated by conventional nozzle discharge sources by several orders of magnitude. The system uses diode lasers to transversely collimate and then to longitudinally slow the atoms, using Zeeman tuning to compensate for the changing Doppler shift. The slowed, collimated beam is then compressed in a 2D magneto-optic trap before a final collimation stage, to achieve the required increase in intensity. Initial experiments using the helium source for some of the applications above are described.
Intense, highly collimated sources of atoms have many potential applications. Bright beams will be important for competitive high flux and high resolution direct-write techniques in lithography, with the added advantage of parallel writing through laser manipulation. Intense sources will also be useful in other atom optic devices e.g. for loading atoms into hollow fiber waveguides. In atomic physics, many collision processes can only be measured with the sensitivity offered by such high flux sources. We report progress on the development of an intense, collimated beam of metastable helium atoms which improves the brightness generated by conventional nozzle discharge sources by several orders of magnitude. The system uses diode lasers to transversely collimate and then to longitudinally slow the atoms, using Zeeman tuning to compensate for the changing Doppler shift. The slowed, collimated beam is then compressed in a 2D magneto-optic trap before a final collimation stage, to achieve the required increase in intensity. Initial experiments using the helium source for some of the applications above are described.