Measurement of Ultrafast Melting and Regrowth Velocities in Pulsed Laser Heated Silicon

1983 ◽  
Vol 23 ◽  
Author(s):  
Philip H. Bucksbaum ◽  
Jeffrey Bokor
Keyword(s):  
Laser Fluence ◽  
Pulsed Laser ◽  
Liquid Films ◽  
Heat Diffusion ◽  
Solid Interface ◽  
Direct Measurements ◽  
Laser Heated ◽  
Good Agreement

ABSTRACTDirect measurements of the liquid/solid interface veiocity have been made during both melt-in and regrowth for puised (20 psec) ultraviolet lasei irradiation or crystailine silicon. The regrowth velocity was 25 m/sec, independent or laser fluence. Regrowtn velocities of 50 to 100 m/sec are expected from heat diffusion calculations which neglect undercooling, whereas the inclusion of an appropriate undercooling curve brings the calculation into good agreement with the data. Tne liquid films produced were up to 40 nm thick and were fully amorphized on resoliaificaion.

Direct measurements of liquid/solid interface kinetics during pulsed‐laser‐induced melting of aluminum

1986 ◽  
Vol 48 (4) ◽  
pp. 278-280 ◽  
Author(s):  
J. Y. Tsao ◽  
S. T. Picraux ◽  
P. S. Peercy ◽  
Michael O. Thompson
Keyword(s):  
Pulsed Laser ◽  
Solid Interface ◽  
Interface Kinetics ◽  
Direct Measurements

Measurement of Fast Melting and Regrowth Velocities in Picosecond Laser Heated Silicon

1983 ◽  
Vol 13 ◽  
Author(s):  
P. H. Bucksbaum ◽  
J. Bokor
Keyword(s):  
Picosecond Laser ◽  
Liquid Films ◽  
Heat Diffusion ◽  
Incident Laser ◽  
Time Resolved ◽  
Light Pulses ◽  
Incident Laser Intensity ◽  
Krf Excimer Laser ◽  
Laser Heated ◽  
Melting Experiment

ABSTRACTFast regrowth of amorphous silicon from liquid silicon films has been directly observed in a time resolved picosecond laser melting experiment. Liquid films up to 100 nm thick were formed on crystalline substrates with 15 picosecond 248 nm pulses from a KrF* excimer laser. The film thickness as a function of time was probed directly by observing attenuation of 1.64 pm 15 psec light pulses transmitted through the melt. Melting and regrowth velocities were compared to a heat diffusion model, and evidence for melt undercooling was observed. The resolidified silicon was amorphous at all values of incident laser intensity.

Pulsed Laser Melting: The Effect of Implanted Solutes on the Resolidification Velocity

1983 ◽  
Vol 23 ◽  
Author(s):  
G. J. Galvin ◽  
J. W. Mayer ◽  
P. S. Peercy
Keyword(s):  
Electrical Conductance ◽  
Pulsed Laser ◽  
Solute Concentration ◽  
Atomic Percent ◽  
Supersaturated Solution ◽  
Solidification Velocity ◽  
Laser Melting ◽  
Solid Interface ◽  
Solution Studies ◽  
Nonequilibrium Segregation

ABSTRACTTransient electrical conductance has been used to measure the resolidification velocity in silicon containing implanted solutes. Nonequilibrium segregation of the solutes occurs during the rapid resolidification following pulsed laser melting. The velocity of the liquid-solid interface is observed to depend on the type and concentration of the solute. A 25% reduction in solidification velocity is observed for an implanted indium concentration of three atomic percent. Implanted oxygen is also shown to reduce the solidification velocity. The dependence of the velocity on solute concentration impacts a variety of segregation, trapping and supersaturated solution studies.

Compartmental modeling of the hepatic transport of taurocholate in the rat in vivo

1989 ◽  
Vol 257 (2) ◽  
pp. G210-G220 ◽  
Author(s):  
X. Deroubaix ◽  
T. Coche ◽  
E. Depiereux ◽  
E. Feytmans
Keyword(s):  
Excretion Rate ◽  
Compartmental Analysis ◽  
Hepatic Transport ◽  
Lumped Model ◽  
Perfusion Model ◽  
Direct Measurements ◽  
Distribution In Blood ◽  
Variability Model ◽  
Good Agreement

Compartmental analysis was used to study the hepatobiliary transport of taurocholate (TC) in the rat in vivo. The available data are the following: [14C]TC kinetics in blood and bile, weighting factors associated with these data and computed from a theoretical variability model, and TC excretion rate in bile. The lumped model that best fits the data contains five compartments: three compartments for TC distribution in blood and two compartments for the liver. It includes a compartmental representation of the laminar flow of bile in the collecting catheter. This model overestimates TC concentration in blood. A perfusion model that includes a compartment representing explicitly the sinusoidal TC concentration gradient was developed. TC concentration in blood estimated by this model is in good agreement with direct measurements, showing that the perfused model has a better descriptive capacity than the lumped model. The amounts of TC estimated in the two hepatic compartments are similar to values previously published.

Rapid nucleation in pulsed laser heated amorphous Si

1989 ◽  
Vol 36 (1-4) ◽  
pp. 588-596 ◽  
Author(s):  
S. Roorda ◽  
W.C. Sinke
Keyword(s):  
Pulsed Laser ◽  
Amorphous Si ◽  
Laser Heated

Theoretically-Based Leidenfrost Point Model

2000 ◽  
Author(s):  
John D. Bernardin ◽  
Issam Mudawar
Keyword(s):  
Bubble Nucleation ◽  
Liquid Gallium ◽  
Interface Temperature ◽  
Sessile Droplet ◽  
Solid Interface ◽  
Leidenfrost Temperature ◽  
Size Characterization ◽  
Surface Cavity ◽  
Effect Of Surface ◽  
Good Agreement

Abstract This study presents a theoretically-based model of the Leidenfrost point (LFP); the minimum liquid/solid interface temperature required to support film boiling on a smooth surface. The model is structured around bubble nucleation, growth, and merging criteria, as well as surface cavity size characterization. It is postulated that for liquid/solid interface temperatures at and above the LFP, a sufficient number of cavities (about 20%) are activated and the bubble growth rates are sufficiently fast that a continuous vapor layer is established nearly instantaneously between the liquid and the solid. The model is applicable to both pools of liquid and sessile droplets. The effect of surface cavity distribution on the LFP predicted by the model is verified for boiling on aluminum, nickel and silver surfaces, as well as on a liquid gallium surface. The model exhibits good agreement with experimental sessile droplet data for water, FC-72, and acetone. While the model was developed for smooth surfaces on which the roughness asperities are of the same magnitude as the cavity radii (0.1–1.0 μm), it is capable of predicting the boundary or limiting Leidenfrost temperature for rougher surfaces with good accuracy.

Optical properties of pulsed laser heated soot

2011 ◽  
Vol 104 (2) ◽  
pp. 307-319 ◽  
Author(s):  
K. A. Thomson ◽  
K. P. Geigle ◽  
M. Köhler ◽  
G. J. Smallwood ◽  
D. R. Snelling
Keyword(s):  
Optical Properties ◽  
Pulsed Laser ◽  
Laser Heated

Effects of Gravity on Rewetting of Capillary Groove Surface at Elevated Temperatures—Experimental and Theoretical Studies

1995 ◽  
Vol 117 (4) ◽  
pp. 1042-1047 ◽  
Author(s):  
S. H. Chan ◽  
J. D. Blake ◽  
T. R. Shen ◽  
Y. G. Zhao
Keyword(s):  
Elevated Temperatures ◽  
Liquid Films ◽  
Thin Liquid Films ◽  
Experimental Investigations ◽  
Plate Temperature ◽  
Groove Surface ◽  
Grooved Surface ◽  
The Difference ◽  
Experimental And Theoretical Studies ◽  
Good Agreement

Theoretical and experimental investigations of the rewetting characteristics of thin liquid films over heated and unheated capillary grooved plates were performed. To investigate the effect of gravity on rewetting, the grooved surface was placed in upward and downward-facing positions. Profound gravitational effects were observed as the rewetting velocity was found to be higher in the upward than in the downward-facing orientation. The difference was even greater with higher initial plate temperatures. With either orientation, it was found that the rewetting velocity increased with the initial plate temperature. But when the temperature was raised above a rewetting temperature, the rewetting velocity decreased with the initial plate temperature. Hydrodynamically controlled and heat conduction controlled rewetting models were then presented to explain and to predict the rewetting characteristics in these two distinct regions. The predicted rewetting velocities were found to be in good agreement with experimental data with elevated plate temperatures.

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