Starting from the left, Electronics Rack Assembly, CO₂ laser, Water-cooled Cu hearth, Levitator Frame Assembly and Gas tank.

Schematic diagram of the aero-acoustic levitation apparatus.

Aero-acoustic levitatior (AAL) is one of the containerless processing tools, which simulates microgravity. It combines the gas-jet levitator and acoustic levitator to achieve stable levitation and positioning of specimens. With CO₂ laser, AAL can levitate and melt materials and suspend liquid drops at high temperatures for extended periods.
The levitation force is provided by aerodynamic force of the upward flowing gas from the nozzle. The gas flow heated to around 400 ℃ produces laminar flow of low-Reynolds number around the levitated object, reducing the thickness of thermal boundary layer that reduces the change of sonic speed by heating the specimen. The AAL method uses active feedback control of the acoustic forces based on specimen position measurements. The feedback control operates in three mutually perpendicular axes which control the three axes of acoustic positioning and influence rotation of levitated specimens[2].
Although AAL can levitate nonelectrical conductive materials, it's hard to maintain well-balanced relations between dynamical pressure of gas flow and surface tention of the specimen. The disturbance of the specimen such as oscillation and rotation is almost same as Acoustic-Levitatior and considerably bigger than that of Electro Magnetic Levitatior (EML). In this regard, however, the capability to be attached diverse equipments like trigger and splat-quench machinery for crystal nucleation features in AAL[1].


-Please save following movies on your desktop first, and check'em out. Don't miss it!
・Success movie (mpeg / 3.16MB)
・Failure movie (mpeg / 2.94MB)

Starting from the left, SEM with EDS, Au-Pd and carbon coater and Polish station.

Unlike the TEM, where electrons are detected by beam transmission, the Scanning Electron Microscope (SEM) produces images by detecting secondary electrons which are emitted from the surface due to excitation by the primary electron beam.[4] The brightness of the signal depends on the number of secondary electrons reaching the detector. The most common imaging mode of a SEM monitors low energy (<50 eV) secondary electrons. Due to their low energy, these electrons originate within a few nanometers from the surface. X-rays, which are also produced by the interaction of electrons with the sample, may also be detected in an SEM equipped for energy dispersive X-ray spectroscopy or wavelength dispersive X-ray spectroscopy. Beyond their scientific value, SEM images are actually interesting.


image by JEOL


Depth of quantum generation and spatial resolution (by Goldstein)


The following are images taken using a scanning electron microscope.

SEM sample pictures

1. Kuribayashi, K., Text for containerless solidification processing.
2. Aero-acoustic levitator operator's manual, Containerless Research,Inc. 1996
3. Weber, J.K.R., Hampton, D.S., Merkley, D.R., Ray, C.A., Zatarski, M.M. and Nordine, P.C., Rev. Sci. Instrum., 65(1994), 456-465.