My Summer Experience Learning Pulsed Power in Germany

Andrew J. Fairbanks

Pulsed power, the application of intense electric fields over very short periods of time, is a well-known enabling technology in plasma and industrial processes.  Recent research has focused on introducing pulsed power technology to the medical industry for treating cancer and delivering genes to cells to induce changes in cellular function.  I spent a month this summer at the Leibniz-Institute for Plasma Science (INP) in Greifswald, Germany under the supervision of Dr. Juergen Kolb, one of the world renowned experts in constructing pulsed power supplies for biomedical applications.  While working with his group, I learned the physics behind generating an electric pulse of a desired duration and voltage and various approaches for constructing these pulse generators. I am applying this experience to my research in the BioElectrics and ElectroPhysics Laboratory at Purdue as we investigate how these electric pulses will impact the function of various types of biological cells in vitro.

Age-dating uranium metal using microstructural damage

Amanda Loveless

Current age-dating technologies for uranium metal provide inadequate information when the material is not chemically purified prior to sample formation. The microstructural damage occurring within the lattice of the metal could provide a time-dependent chronometer to enable sample age determination. As isotopes in the metal decay, the recoil particles travel throughout the lattice and dislocate surrounding atoms. Preliminary simulations indicate the feasibility of this method for highly-enriched uranium (HEU) and high assay low-enriched uranium (LEU) while suggesting lower feasibility for enrichments below commercial LEU. These analyses motivate future simulations and experiments to optimize sample preparation for inspection

Effect of Transverse Magnetic Field on Carbon Laser Produced Plasma

Faisal Odeh

The plasma hydrodynamic expansion properties and emission features can be controlled by external magnetic field. We investigated the effect of the magnetic field confinement of carbon laser-produced plasmas. We used an Nd:YAG pulsed laser (λ:1064 nm and FWHM:6 ns) to generate laser ablation plumes. A magnetic trap was designed with nearly uniform magnetic field strength of 0.8T. The generated carbon plasma was allowed to expand onto a transverse magnetic field. The experiment was conducted in vacuum.

Three different plasma diagnostics were used to study the dynamics of the transient plasma. First, fast photography was performed using an intensified charged coupled device (ICCD) to study the plume dynamics. A transverse magnetic field confined the plume expansion compared to free expanding plasma. Second, optical emission spectroscopy was used to determine the temperature, electron density, and emission intensities. The transverse magnetic field enhanced the emission of singly and doubly ionized carbon lines while reducing excited neutrals. The magnetic field did not significantly change electron density while electron temperature increased due to Joule heating (JXB). Finally, Time of Flight (TOF) showed a significant reduction in the speed and a longer persistence of all species.