Induced Local EMP and Secondary THz Radiation in Sensor Window Materials from Intense Femtosecond Pulses at Long Range

"This project seeks to study the potential use of high-frequency RF pulses generated by an ultrashort-pulse laser-produced plasma, as a means of disrupting the sensors of an aircraft or missile. Femtosecond laser plasmas can propagate over extendeddistances at very high intensity in the form of self-trapped filaments. This high intensity radiation can disrupt sensors and guidance systems both by direct damage, and by creating a short-lived plasma on the sensor window. This plasma emits broadbandradiation, ranging from the RF into the x-ray region of the spectrum. In phase I, we plan to evaluate through modeling the possible field strength of the emission in the RF to terahertz range, in order to estimate the potential of this emission to disruptsensors. We will also plan a series of experiments that can thoroughly characterize and parameterize this emission. The result, after phase II, will be a better understanding of the capabilities of this process for countermeasures applications. The resultof this work will be a better understanding of the potential for high intensity femtosecond lasers to serve in countermeasures applications. Phase I will serve to evaluate this process, based on modeling and a compilation of current understanding of thephysics of laser-plasma interactions, and will help to determine fruitful directions for further experimentation. Phase II will serve as experimental confirmation of the physical understandings d