Re: Thermal Waves ?

[Larry Woolf <Larry.Woolf@GAT.COM>]

A similar laser flash diffusivity technique is used to measure the thermal
properties of materials.

The technique is based on the measurement of the thermal transient of the
rear surface of the sample
when a pulsed laser illuminates the front surface.

W.J. Parker, R.J. Jenkins, C.P. Butler, G.L. Abbot,
"Flash Method of Determing Thermal Diffusivity, Heat
Capacity and Thermal Conductivity", J. Appl. Phys. 32. pp.1679-84, 1964.

At 2:02 PM -0700 11/23/2002, Michael Edmiston wrote:
 The laser pulse created a hot spot that propagated radially
> from the point where the beam went through the wafer.  If the four
> contacts rose in temperature at the same time, the laser beam was
> centered on the wafer.  If the beam was not centered we could determine
> its offset from center by the differing times of arrival of the thermal
> "wavefront" at each of the four contacts.

Larry Woolf,General Atomics,San Diego, CA 92121; Phone: 858-526-8575; FAX:
858-455-8568

This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.