1904 A region of generation of side jets in round, low-density gas jets

2008 ◽  
Vol 2008.2 (0) ◽  
pp. 207-208
Author(s):  
Akinori MURAMATSU ◽  
On Ishikawa ◽  
Tomoya SASAKI
Keyword(s):  
Low Density ◽  
Gas Jets

scholarly journals Gravitational Effects on Near-Field Flow Structure of Low-Density Gas Jets

AIAA Journal ◽  
2003 ◽  
Vol 41 (10) ◽  
pp. 1973-1979 ◽  
Author(s):  
Tze-Wing Yep ◽  
Ajay K. Agrawal ◽  
DeVon Griffin
Keyword(s):  
Flow Structure ◽  
Near Field ◽  
Low Density ◽  
Gravitational Effects ◽  
Gas Jets

scholarly journals Computational Analysis of Gravitational Effects in Low-Density Gas Jets

AIAA Journal ◽  
2006 ◽  
Vol 44 (7) ◽  
pp. 1505-1515 ◽  
Author(s):  
Rajani P. Satti ◽  
Ajay K. Agrawal
Keyword(s):  
Computational Analysis ◽  
Low Density ◽  
Gravitational Effects ◽  
Gas Jets

scholarly journals Buoyancy effects on flow transition in low-density inertial gas jets

2005 ◽  
Vol 38 (4) ◽  
pp. 541-544 ◽  
Author(s):  
Kasyap S. Pasumarthi ◽  
Ajay K. Agrawal
Keyword(s):  
Low Density ◽  
Flow Transition ◽  
Gas Jets

scholarly journals Multi-pass probing for high-sensitivity tomographic interferometry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stefan Karatodorov ◽  
Roberto Lera ◽  
Marek Raclavsky ◽  
Sebastian Lorenz ◽  
Uddhab Chaulagain ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Low Density ◽  
Phase Sensitivity ◽  
Characterization Methods ◽  
Gas Jets ◽  
Barrel Shock ◽  
Optical Probing ◽  
Novel Method ◽  
Indispensable Tool ◽  
Set Up

AbstractOptical probing is an indispensable tool in research and development. In fact, it has always been the most natural way for humankind to explore nature. However, objects consisting of transparent materials with a refractive index close to unity, such as low-density gas jets, are a typical example of samples that often reach the sensitivity limits of optical probing techniques. We introduce an advanced optical probing method employing multiple passes of the probe through the object to increase phase sensitivity, and relay-imaging of the object between individual passes to preserve spatial resolution. An interferometer with four-passes was set up and the concept was validated by tomographic characterization of low-density supersonic gas jets. The results show an evident increase of sensitivity, which allows for the accurate quantitation of fine features such as a shock formed by an obstacle or a barrel shock on the jet boundary in low ambient gas pressures. Despite its limitations in temporal resolution, this novel method has demonstrated an increase in phase sensitivity in transmission, however, it can also be employed to boost the absorption or polarization contrast of weakly interacting objects in both transmission and reflection setups, thus, upgrading the sensitivity of various optical characterization methods.

Application of Improved Voltage Compensation in the SEM to Imaging of Organic Materials

1973 ◽  
Vol 31 ◽  
pp. 444-445
Author(s):  
P.J. Killingworth ◽  
M. Warren
Keyword(s):  
Electron Beam ◽  
Organic Materials ◽  
Operating Parameters ◽  
Low Density ◽  
Beam Diameter ◽  
Incident Electron Beam ◽  
Specimen Material ◽  
Voltage Compensation ◽  
Selection Of ◽  
Scanning Electron

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.

Quantitative defect studies in semiconductor TEM samples prepared by low angle ion milling

1995 ◽  
Vol 53 ◽  
pp. 512-513
Author(s):  
L. Mulestagno ◽  
J.C. Holzer ◽  
P. Fraundorf
Keyword(s):  
Sample Preparation ◽  
Milling Time ◽  
High Density ◽  
Low Density ◽  
Ion Milling ◽  
High Quality ◽  
Variable Angle ◽  
Major Disadvantage ◽  
Induced Defects

Due to the wealth of information, both analytical and structural that can be obtained from it TEM always has been a favorite tool for the analysis of process-induced defects in semiconductor wafers. The only major disadvantage has always been, that the volume under study in the TEM is relatively small, making it difficult to locate low density defects, and sample preparation is a somewhat lengthy procedure. This problem has been somewhat alleviated by the availability of efficient low angle milling.Using a PIPS® variable angle ion -mill, manufactured by Gatan, we have been consistently obtaining planar specimens with a high quality thin area in excess of 5 × 104 μm2 in about half an hour (milling time), which has made it possible to locate defects at lower densities, or, for defects of relatively high density, obtain information which is statistically more significant (table 1).

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