Thermal Diffusivity of Diamond Films Using a Laser Pulse Technique

1990 ◽  
Vol 137 (6) ◽  
pp. 1973-1976 ◽  
Author(s):  
Sacharia Albin ◽  
William P. Winfree ◽  
B. Scott Crews
Keyword(s):  
Thermal Diffusivity ◽  
Laser Pulse ◽  
Diamond Films ◽  
Pulse Technique

Measurement of Thermal Diffusivity by Laser Pulse

1967 ◽  
Vol 6 (8) ◽  
pp. 1019-1019 ◽  
Author(s):  
Susumu Namba ◽  
Pil Hyon Kim ◽  
Tsutomu Arai ◽  
Takeo Kikuchi
Keyword(s):  
Thermal Diffusivity ◽  
Laser Pulse

Thermal diffusivity of heteroepitaxial diamond films: Experimental setup and measurements

2010 ◽  
Vol 19 (7-9) ◽  
pp. 787-791 ◽  
Author(s):  
C. Stehl ◽  
M. Schreck ◽  
M. Fischer ◽  
S. Gsell ◽  
B. Stritzker
Keyword(s):  
Thermal Diffusivity ◽  
Diamond Films ◽  
Experimental Setup

scholarly journals Effect of self focusing on the prolongation of laser produced plasma channel

2009 ◽  
Vol 27 (1) ◽  
pp. 33-39 ◽  
Author(s):  
U. Verma ◽  
A.K. Sharma
Keyword(s):  
Theoretical Model ◽  
Time Delay ◽  
Laser Pulse ◽  
Density Profile ◽  
Plasma Channel ◽  
Ion Density ◽  
Pulse Technique ◽  
Recombination Time ◽  
Self Focusing ◽  
Gaseous Plasma

AbstractA theoretical model for the prolongation of lifetime of a gaseous plasma channel formed by two pulse technique at laser intensities below the tunnel ionization threshold is developed. The first laser pulse ionizes the gas completely on the axis and partially off the axis, causing self-defocusing of the pulse. After the passage of the pulse, the plasma expands radially, creating an atom/ion density profile with a minimum on the axis. Partial recombination also sets in. As the second pulse arrives, after a time delay of less than the recombination time (~ns), the electrons get heated, and the recombination rate is slowed down. The second pulse self focuses, enhancing the heating rate and lengthening the lifetime of the plasma channel.

Thermal Diffusivity of Diamond Films With Substrates

1995 ◽  
Vol 12 (8) ◽  
pp. 477-480
Author(s):  
Cui Jingbiao ◽  
Fang Rongchuan
Keyword(s):  
Thermal Diffusivity ◽  
Diamond Films

Thermal Diffusivity of Uranium by Laser Pulse Method from 20°to 850°C

1968 ◽  
Vol 7 (6) ◽  
pp. 682-682 ◽  
Author(s):  
Shōichi Nasu ◽  
Susumu Fukushima ◽  
Toshihiko Ohmichi ◽  
Takeo Kikuchi
Keyword(s):  
Thermal Diffusivity ◽  
Laser Pulse ◽  
Pulse Method ◽  
Laser Pulse Method

Investigation of Nano/Microcrystalline Diamond Composite Films for Thermal Applications

2009 ◽  
Vol 610-613 ◽  
pp. 563-566
Author(s):  
Yu Lan Guan ◽  
Wen Qi Dai ◽  
Lin Jun Wang ◽  
Jian Huang ◽  
Jian Ming Lai ◽  
...  
Keyword(s):  
Thermal Diffusivity ◽  
Composite Film ◽  
Composite Films ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Atomic Force Microscope Image ◽  
Diamond Composite ◽  
Grain Sizes ◽  
Atomic Force ◽  
Hot Filament

A newly developed nano/microcrystalline diamond composite film for thermal applications was prepared in this investigation. A microcrystalline diamond (MCD) film was deposited onto silicon substrate by hot filament chemical vapor deposition (HFCVD) method, and then a nanocrystalline diamond (NCD) film was grown onto this MCD film to obtain a NCD/MCD composite film. The root-mean-square (RMS) value of surface roughness for the composite film estimated from the atomic force microscope image was 42.7nm. Compared with 85.9nm for the MCD film. And it was also found that the thermal diffusivity increased from 32.61mm2/s to 37.63mm2/s by further growing a NCD film. Results indicated that the deposition of NCD film reduced the rough surface of the MCD film with grain sizes of the order of microns, and thus increased the efficiency of diamond films as thermal spreading device. It was found that the NCD/MCD composite film had a smoother surface and a higher thermal diffusivity compared with MCD film.

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