Mitigation of Oxygen Attachment in High Pressure Air Plasmas by Vibrational Excitation

2004 ◽  
Author(s):  
Kraig Frederickson ◽  
Wonchul Lee ◽  
Igor Adamovich ◽  
J. Rich ◽  
Walter Lempert ◽  
...  
Keyword(s):  
High Pressure ◽  
Vibrational Excitation ◽  
Air Plasmas

Mitigation of electron attachment to oxygen in high pressure air plasmas by vibrational excitation

2007 ◽  
Vol 101 (9) ◽  
pp. 093302 ◽  
Author(s):  
K. Frederickson ◽  
W. Lee ◽  
P. Palm ◽  
I. V. Adamovich ◽  
J. W. Rich ◽  
...  
Keyword(s):  
High Pressure ◽  
Vibrational Excitation ◽  
Electron Attachment ◽  
Air Plasmas

Analysis of the power budget and stability of high-pressure nonequilibrium air plasmas

2000 ◽  
Author(s):  
Igor Adamovich ◽  
J. Rich ◽  
Andrey Chernukho ◽  
Serguei Zhdanok
Keyword(s):  
High Pressure ◽  
Power Budget ◽  
Air Plasmas

Vibrational Spectra of a-Si:H Obtained by Pds

1991 ◽  
Vol 219 ◽  
Author(s):  
E. Lotter ◽  
M. B. Schubert ◽  
M. Heintze ◽  
G. H. Bauer
Keyword(s):  
High Pressure ◽  
Vibrational Spectra ◽  
Molecular Hydrogen ◽  
Vibrational Excitation ◽  
High Energy ◽  
Absorption Profile ◽  
Additional Absorption ◽  
Photothermal Deflection Spectroscopy ◽  
Photothermal Deflection ◽  
Photo Current

ABSTRACTIn the energy range below mid-gap, absorption spectra obtained by photothermal deflection spectroscopy (PDS) show much higher values than data evaluated from photo-current measurements. This difference can now be explained as an additional absorption arising from combined vibrational excitation of molecular hydrogen and Si-H stretching modes, which can occur when the H2 molecule is deformed in a collision with Si-H. Down to lower energies, our samples absorb even stronger than in mid-gap. Extension of spectral scans down to photon energies of 0.4 eV shows that this results from absorption of the high energy wings of the collision induced H2 absorption, which is superimposed by the first overtone of the Si-H and Si-H2 stretching modes. The analysis of the H2 absorption profile and strength on samples as grown and annealed gives evidence that molecular hydrogen is enclosed in small cavities and polarized by anisotropic environment in as-grown material while it is concentrated in larger voids under high pressure after annealing above 350°C.

High pressure air plasmas sustained by an electron beam and enhanced by optical pumping

2001 ◽  
Author(s):  
Peter Palm ◽  
Elke Plonjes ◽  
Igor Adamovich ◽  
Vish Subramaniam ◽  
Walter Lempert ◽  
...  
Keyword(s):  
High Pressure ◽  
Electron Beam ◽  
Optical Pumping ◽  
Air Plasmas

Radiative properties and radiative transfer in high pressure thermal air plasmas

2012 ◽  
Vol 45 (45) ◽  
pp. 455203 ◽  
Author(s):  
B Peyrou ◽  
L Chemartin ◽  
Ph Lalande ◽  
B G Chéron ◽  
Ph Rivière ◽  
...  
Keyword(s):  
High Pressure ◽  
Radiative Transfer ◽  
Radiative Properties ◽  
Air Plasmas

Electron-beam generated high pressure air plasmas enhanced by optical pumping

2001 ◽  
Author(s):  
Igor Adamovich ◽  
J. Rich ◽  
Peter Palm ◽  
Elke Plonjes ◽  
Matt Buoni ◽  
...  
Keyword(s):  
High Pressure ◽  
Electron Beam ◽  
Optical Pumping ◽  
Air Plasmas

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

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