We report the slowing of a supersonic beam by elastic reflection from a receding atomic mirror. We use a pulsed supersonic nozzle to generate a $511\ifmmode\pm\else\textpm\fi{}9\text{ }\text{ }\mathrm{m}/\mathrm{s}$ beam of helium that we slow by reflection from a $\mathrm{Si}(111)\mathrm{\text{\ensuremath{-}}}\mathrm{H}(1\ifmmode\times\else\texttimes\fi{}1)$ crystal placed on the tip of a spinning rotor. We were able to reduce the velocity of helium by $246\text{ }\text{ }\mathrm{m}/\mathrm{s}$ and show that the temperature of the slowed beam is lower than 250 mK in the comoving frame.We report the slowing of a supersonic beam by elastic reflection from a receding atomic mirror. We use a pulsed supersonic nozzle to generate a $511\ifmmode\pm\else\textpm\fi{}9\text{ }\text{ }\mathrm{m}/\mathrm{s}$ beam of helium that we slow by reflection from a $\mathrm{Si}(111)\mathrm{\text{\ensuremath{-}}}\mathrm{H}(1\ifmmode\times\else\texttimes\fi{}1)$ crystal placed on the tip of a spinning rotor. We were able to reduce the velocity of helium by $246\text{ }\text{ }\mathrm{m}/\mathrm{s}$ and show that the temperature of the slowed beam is lower than 250 mK in the comoving frame.

arXiv:physics/0701003Physical Review LettersMar 7, 200742 citations

A "heat pipe"-style recirculating lithium oven for entrainment into supersonic helium beams

Lukas Gerhard Georg Gradl

This thesis presents the work on a new oven design optimized for the\nentrainment of lithium into a pulsed supersonic beam of helium. The\nproposed oven does not pollute the vacuum with lithium atoms that are\nnot entrained, but instead is designed to capture and recirculate all\natoms that are not carried away by the supersonic beam. The\ntransportation of lithium inside the oven is reminiscent of a heat\npipe, coining the nickname of the oven: Lithium is evaporated in a hot\nreservoir, recondensed at a cold surface, and recirculated to the hot\nreservoir using capillary action.\n\nThe supersonic helium beam is generated by an Even-Lavie valve\nyielding a cold and collimated flow of gas. The supersonic beam can\nbe further collimated by using a skimmer. Two different heat-pipe\noven designs are investigated in this thesis, one for entrainment\ndownstream of the skimmer and on for entrainment upstream of the\nskimmer.\n\nDownstream of the skimmer, the lithium that is carried in the helium\nbeam behind the oven is much hotter and slower than the carrier gas.\nThis is due to the low density of the helium beam past the skimmer,\nwhich does not support enough collisions with the lithium atoms to\nreach equilibrium.\n\nUpstream of the skimmer, the helium density is higher and the beam\nbehaves in part like continuous flow and the interaction with the oven\nheats the supersonic beam considerably. The lithium content in the\nbeam that was measured past the skimmer is faster and hotter than the\nhelium flow. It is also not properly entrained, but pushed along by\nthe helium beam.\n\nFrom these experiments it is obvious, that entrainment depends\ncrucially of the local properties of the supersonic beam at the\nentrainment site. To be more flexible in the choice of this\nparameter, a new design for a heat-pipe oven is proposed, which allows\nfor linear translation along the propagation direction of the beam,\nupstream of the skimmer.This thesis presents the work on a new oven design optimized for the\nentrainment of lithium into a pulsed supersonic beam of helium. The\nproposed oven does not pollute the vacuum with lithium atoms that are\nnot entrained, but instead is designed to capture and recirculate all\natoms that are not carried away by the supersonic beam. The\ntransportation of lithium inside the oven is reminiscent of a heat\npipe, coining the nickname of the oven: Lithium is evaporated in a hot\nreservoir, recondensed at a cold surface, and recirculated to the hot\nreservoir using capillary action.\n\nThe supersonic helium beam is generated by an Even-Lavie valve\nyielding a cold and collimated flow of gas. The supersonic beam can\nbe further collimated by using a skimmer. Two different heat-pipe\noven designs are investigated in this thesis, one for entrainment\ndownstream of the skimmer and on for entrainment upstream of the\nskimmer.\n\nDownstream of the skimmer, the lithium that is carried in the helium\nbeam behind the oven is much hotter and slower than the carrier gas.\nThis is due to the low density of the helium beam past the skimmer,\nwhich does not support enough collisions with the lithium atoms to\nreach equilibrium.\n\nUpstream of the skimmer, the helium density is higher and the beam\nbehaves in part like continuous flow and the interaction with the oven\nheats the supersonic beam considerably. The lithium content in the\nbeam that was measured past the skimmer is faster and hotter than the\nhelium flow. It is also not properly entrained, but pushed along by\nthe helium beam.\n\nFrom these experiments it is obvious, that entrainment depends\ncrucially of the local properties of the supersonic beam at the\nentrainment site. To be more flexible in the choice of this\nparameter, a new design for a heat-pipe oven is proposed, which allows\nfor linear translation along the propagation direction of the beam,\nupstream of the skimmer.

Jan 1, 20170 citations

Wave Physics

B. Esser

Zeitschrift für Physikalische ChemieJan 1, 19941 citation

Towards coherent control of supersonic beams: a new approach to atom optics

A. Libson, Max F. Riedel, G Bronshtein +3 more

A supersonic beam of noble gas atoms is a source of unprecedented brightness. A novel short pulse supersonic nozzle is developed with beam intensity that is higher by at least an order of magnitude than other available sources. We show how this beam can be coherently slowed and focused using elastic reflection from single crystals. Simulations show beam fluxes of 10 11 atoms s −1 at velocities of 50 m s −1 and temperatures of less than 20 μK in the longitudinal direction. Possible applications of this slow beam to the study of atom–surface interactions and atom interferometry are discussed.A supersonic beam of noble gas atoms is a source of unprecedented brightness. A novel short pulse supersonic nozzle is developed with beam intensity that is higher by at least an order of magnitude than other available sources. We show how this beam can be coherently slowed and focused using elastic reflection from single crystals. Simulations show beam fluxes of 10 11 atoms s −1 at velocities of 50 m s −1 and temperatures of less than 20 μK in the longitudinal direction. Possible applications of this slow beam to the study of atom–surface interactions and atom interferometry are discussed.

New Journal of PhysicsMay 30, 200621 citations

246\text{ }\text{ }\mathrm{m}/\mathrm{s}

and show that the temperature of the slowed beam is lower than 250 mK in the comoving frame.