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Graduate Exam Abstract


Michael Purvis

Ph.D. Final

June 27, 2014, 9AM

Physics - Hammond Room

Relativistic plasma nano-photonics for ultra-high energy density physics


Abstract: The trapping of femtosecond laser pulses of relativistic intensity deep within ordered nanowire arrays is shown to volumetrically heat near solid density matter transforming it into ultra-hot highly ionized plasmas. The plasmas were generated by focusing intense ~ 60 femtosecond duration ultra-high-contrast laser pulses onto targets consisting of arrays of densely packed vertically aligned nanowires 35-80 nm diameter. X-ray spectra are presented showing that irradiation of Ni and Au nanowire arrays heats a plasma volume several µm in depth to reach extraordinarily high degrees of ionization (i.e. 26 times ionized Ni , 52 times ionized Au), in the process generating gigabar level pressures. Electron densities nearly 100 times greater than the typical critical density and multi-keV temperatures are achieved using laser pulses of only 0.5 J energy. The large plasma volume and high electron density lead to an increased hydrodynamic-to-radiative lifetime ratio that results in a significant increase in X-ray yield. Measurements from a filtered photodiode array reveal a 100X increase in emission with respect to polished flat targets for photons with energies greater than 9keV. Scaling to higher laser intensities promises to create plasmas with temperatures and pressures approaching those in the center of the sun.

Adviser: Jorge Rocca
Co-Adviser: N/A
Non-ECE Member: Azer Yalin, Mechanical Engineering
Member 3: Carmen Menoni, Electrical Engineering
Addional Members: Mario Marconi, Electrical Engineering

Publications:


J. Filevich, J. Grava, M. Purvis, M. C. Marconi, and J. J. Rocca, J. Nilsen, J. Dunn, and W.R. Johnson, "Prediction and observation of tin and silver plasmas with index of refraction greater than one in the soft x-ray range", Physical Review E 74, 016404, (2006).

J. Filevich, J. Grava, M. Purvis, M. C. Marconi, J. J. Rocca, J. Nilsen, J. Dunn, and W. R. Johnson, "Multiply ionized carbon plasmas with index of refraction greater than one", Laser and Particle Beams 25, 1 (2007).

M. Purvis, J. Grava, J. Filevich, M. C. Marconi, J. J. Rocca, J. Dunn, S. J. Moon, V. N. Shyaptsev, E. Jankowska, "Dynamics of converging laser-created plasmas in semi-cylindrical cavities studied using soft x-ray laser interferometry", Physical Review E, 76, 046402 (2007).

J. Grava, M.A. Purvis, J. Filevich, M.C. Marconi, J.J. Rocca, J. Dunn, S.J. Moon, V.N. Shlyaptsev, "Dynamics of a dense laboratory plasma jet investigated using soft x-ray laser interferometry," Physical Review E, 78, 016403 (2008).

J. Nilsen, J.I. Castor, C.A. Iglesias, K.T. Cheng, J. Dunn, W.R. Johnson, J. Filevich, M.A. Purvis, J. Grava, and J.J. Rocca, "Understanding the anomalous dispersion of doubly-ionized carbon plasmas near 47 nm," High Energy Density Physics, 4, pg 107-113, (2008).

M. Purvis, J. Grava, J. Filevich, M.C. Marconi, J. Dunn, S.J. Moon, V.N. Shlyaptsev, E. Jankowska, and J.J. Rocca, "Soft x-ray laser interferometry of colliding laser-created plasmas in semi-cylindrical cavities," IEEE Transactions on Plasma Sciences 36, 4, 1134, (2008).

J. Grava, M.A. Purvis, J. Filevich, M.C. Marconi, J. Dunn, S.J. Moon, V.N. Shlyaptsev, and J.J. Rocca, "Soft X-Ray Laser Interferometry of a Dense Plasma Jet", IEEE Transactions on Plasma Sciences 36, 4, 1286, (2008).

J. Nilsen, J. I. Castor, C.A. Iglesias, K.T. Cheng, J. Dunn, W.R. Johnson, J. Filevich, M.A. Purvis, J. Grava, J. J. Rocca,, "Understanding the anomalous dispersion of doubly ionized carbon plasmas near 47nm." High Energy Density Physics, 4 (2008).

J. Dunn, E. W. Magee, R. Shepherd, H. Chen, S. B. Hansen, S. J. Moon, G. V. Brown, M.-F. Gu, P. Beiersdorfer, and M. A. Purvis, "High resolution soft x-ray spectroscopy of low Z K-shell emission from laser-produced plasmas," Rev. Sci. Instrum. 79, 10E314 (2008), DOI:10.1063/1.2968704

J. Filevich, M. Purvis, J. Grava, D.P. Ryan, J. Dunn, S.J. Moon, V.N. Shlyaptsev, and J.J. Rocca, "Bow shocks formed by plasma collisions in laser irradiated semi-cylindrical cavities," High Energy Density Physics (2009), doi: 10.1016/j.hedp.2009.04.003

J. Colgan, J. Abdallah Jr., C. J. Fontes, D. P. Kilcrease, J. Dunn, M. Purvis, and R.W. Lee, "Non-LTE and gradient effects in K-shell oxygen emission laser-produced plasma," High Energy Density Physics (2010), doi:10.1016/j.hedp.2010.01.015

M. A. Purvis, J. Grava, J. Filevich, D. P. Ryan, S. J. Moon, J. Dunn, V. N. Shlyaptsev and J. J. Rocca, "Collimation of dense plasma jets created by low-energy laser pulses and studied with soft x-ray interferometry," Physical Review E 81, (2010).

N. Rohringer, D. Ryan, R.A. London, M. Purvis, F. Albert, J. Dunn, J. D. Bozek, C. Bostedt, A. Graf, R. Hill, S. P. Hau-Riege, and J. J. Rocca, Nature 481, 488.

K. C. Cone, H. A. Baldis, J. Dunn, M. J. May, M.A. Purvis, M.B. Schneider, and H.A. Scott, "Time-resolved soft x-ray spectra from laser-produced Cu plasma, Rev. Sci. Inst. 83, (2012).

C. Weninger, M. Purvis, D. Ryan, R. A. London, J. D. Bozek, C. Bostedt, A. Graf, G. Brown, J. J. Rocca, and N. Rohringer, Stimulated Electronic X-ray Raman Scattering, Phys. Rev. Lett. 111, (2013).

M. A. Purvis, V.N. Shlyaptsev, R. Hollinger, C. Bargsten, A. Pukhov, A. Prieto, Y. Wang, B. M. Luther, L. Yin, S. Wang, and J. J. Rocca. Relativistic plasma nano-photonics for ultra-high energy density physics, Nature Photonics 7, 796-780 (2013).


Program of Study:
PHYS 771C
EE 777
EE 680
EE 580
EE 581
EE 580
EE 580
EE 641