Evidence for a nuclear hexadecapole interaction in the hyperfine spectrum of LiI

The molecular beam electric resonance technique has been used to examine the hyperfine spectrum of 7LiI to determine the nuclear hexadecapole interaction of the iodine nucleus. The nuclear magnetic octupole interaction was also considered but found to be marginally significant. A total of 172 transitions in vibrational states 0-3 and rotational states 1-6 have been included in a fit to determine the iodine nuclear quadrupole, spin-rotation, and hexadecapole interactions, the lithium quadrupole and spin-rotation interactions, and the tensor and scalar parts of the spin-spin interaction. Vibration and rotation dependencies of these constants have been determined

Polarization-sensitive lidar methods for biological agent detection

Detection and discrimination of aerosolized biological weapons at standoff distances has proven to be a challenging task. Traditional approaches have proven to be successful for many types of applications, but have shown limitations under specific conditions. For instance, Ultra Violet Laser Induced Fluorescence (UV-LIF) has been the detection standard for many years, yet this technique is known to struggle to discriminate among biological aerosols as well as certain interferents. Lockheed Martin Coherent Technologies has developed a new detection scheme relying on multi-spectral polarization signatures to detect and discriminate biological agents from other non-biological aerosols as well as identification among different types of biological agents. This technique has proven to be successful against a variety of interferents including diesel exhaust. The polarization-sensitive method takes advantage of the morphology of the target aerosols as well as their absorptive properties which modifies the scattering of the multi-spectral light. This technique has unique potential for long-range standoff detection of biological agents operating in all light conditions (including daylight) in real-world battlefield environments. Fielded systems relying on this type of detection scheme have been proven successful in numerous field campaigns over a wide range of atmospheric conditions