Graduate Exam Abstract
August 8, 2017, 1:00 pm - 3:00 pm
Ultra high energy density plasmas from high contrast, relativistic laser irradiation of aligned nanowire arrays
Abstract: Ultra high energy density (UHED) plasmas, characterized by energy densities >1x108Jcm-3 and pressures greater than a gigabar
are encountered in the center of stars and in inertial confinement fusion capsules driven by the world's largest lasers. Similar
conditions can be obtained with compact, ultrahigh contrast, femtosecond lasers focused to relativistic intensities onto aligned
nanowire array targets. Experiments conducted at CSU have measured a record x-ray conversion efficiency of 20% from this
scheme at a moderate intensity of 5x1019Wcm-2. Other experiments have included characterizing the time that it takes for the
wires to explode and form a supercritical density plasma, as well as the heat penetration depth in the wires. Currently, we have
extended the capabilities of the laser system to reach intensities >1022Wcm-2 where we will attempt to take moderate resolution
spectra of high ionization emission from mid Z elements such as Rhodium, Silver and Tin. These experiments promise to create
UHED matter at unprecedented pressures. In addition to this, we will attempt to measure our first set of time resolved K-shell and
He-like spectral emission in order to gain insight into the time scale of ionization processes and radiation transport.
Adviser: Jorge Rocca
Non-ECE Member: Amy Prieto, Chemistry
Member 3: Mario Marconi, ECE
Addional Members: Carmen Menoni, ECE
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 nanophotonics for ultrahigh energy density physics," Nature Photonics 7, 796?800 (2013).
C. Bargsten, R. Hollinger, M. G. Capeluto, V. Kaymak, A. Pukhov, S.
Wang, A. Rockwood, Y. Wang, D. Keiss, R. Tommasini, R. London, J.
Park, M. Busquet, M. Klapisch, V. N. Shlyaptsev, and J. J. Rocca, "Energy penetration into arrays of aligned nanowires irradiated with relativistic intensities: Scaling to terabar pressures," Sci. Adv. 3,
R. Hollinget et al "Efficient picosecond x-ray pulse generation from plasmas in the radiation dominated regime." in review at Optica
R. Hollinger, C. Bargsten, V. Shlyaptsev, D. Keiss, A. Townsend, A.
Rockwood, Y. Wang, S. Wang, J. J. Rocca, and A. Pukhov, "Time limit for the efficient coupling of relativistic femtosecond laser pulses into aligned nanowire arrays," in APS Meeting Abstracts (2015).
J. J. Rocca, V. Shlyaptsev, R. Hollinger, C. Bargsten, A. Pukhov, V.
Kaymak, R. Tommasini, R. London, J. Park, and M. Gabriela Capeluto, "Compact ultra-intense lasers and nanostructures open a path to extreme pressures," LASER Focus WORLD 53, 21?26 (2017).
M. Hill, P. Allan, C. Brown, D. Hoarty, L. Hobbs, S. James, C.
Bargsten, R. Hollinger, J. Rocca, and J. Park, "X-ray and gamma ray emission from petawatt laser-driven nanostructured metal targets," in APS Meeting Abstracts (2016).
J. Park, R. Tommasini, R. London, J. Rocca, R. Hollinger, C. Bargsten, V. Shlyaptsev, H. Chen, A. Pukhov, and M. Capeluto, Creation of Ultra-High Energy Density Matter Using Nanostructured Targets on Titan Laser (Lawrence Livermore National Laboratory (LLNL), Livermore, CA,
Program of Study: