Matt DeCamp
Courses Taught
The DeCamp lab (Sharp 012) aims to study the ultrafast (sub-picosecond) dynamics of complex systems. This ranges from the structural dynamics of crystalline systems to the molecular dynamics of biomolecules in solution. The DeCamp Lab is developing several time-domain spectroscopic tools to fulfill these goals, including time-resolved x-ray scattering and time-domain THz spectroscopy.
Laser system:
The backbone of any ultrafast spectroscopy lab is the laser source. The DeCamp lab has a 1kHz Spectra-Physics Spitfire XP amplifier seeded by a KMLabs Oscillator. The laser generates 3mJ, sub-40fs laser pulses for ultrafast spectroscopy. The laser output is currently being upgraded to 7+mJ at 1kHz by the instillation of a cyro cooled multipass power amplfier. Using modest focusing, this laser will be able to generated fields greater than 10^17W/cm2. The DeCamp is also currently constructing a power amplifier for this laser system, which should increase the output optical pulse energy by a factor of 3.
Time-resolved x-ray scattering:
The main tools being developed in the DeCamp lab is the construction and development of an ultrafast x-ray source. The pulsed x-ray source is based upon the generation of a dense plasma via intense (>10^15 W/cm2) laser excitation of solid targets, specifically a copper wire. Below is a photograph of this laser generated plasma.
The preliminary x-ray spectrum of this source is shown below. The two narrow peaks are the copper k-alpha and k-beta lines. The lines are riding atop the bremstrahlung continuum background. The data was taken with an Amptek x-123 spectrometer. Current the x-ray source is located in open air resulting a limited optical pulse focussing parameters and relatively low x-ray yeild.
It is anticipated that the generated x-ray pulses are sub-picosecond. Diagnostic tests are now underway, including x-ray yield optimization and x-ray pulse length.
Time-domain THz spectroscopy:
THz radiation is the wavelength range of .020-1mm and can have pulsed lengths as fast as 30fs. While these wavelengths are relatively long, it is the spectral region of low frequency molecular vibrations and rotations, making this a useful range for molecular spectroscopy. Producing pulsed THz radiation can easily accomplished by rapidaly accelerating charged particles. This is typcially accomplished via ultrafast excitation of semiconductors or the rapid generation of a dense electron plasma. We have recently produced and measured coherent THz radiation from a dense laser-driven plasma in a copper target. This radiation is a direct measurement of the electron dynamics within the plasma, providing a novel method to performing laser-plasma diagnostics.
Contact Information
Matt F. DeCamp
University of Delaware
Physics & Astronomy
223 Sharp Laboratory
Newark, DE 19716
email:mdecamp@udel.edu
24hr best way to communicate
phone: 302-831-2671
fax: 302-831-1637
Office: 235 Sharp Lab
Laboratory: 012/012A Sharp Laboratory