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Full-Text Articles in Physics
Control Of Bright Picosecond X-Ray Emission From Intense Subpicosecond Laser-Plasma Interactions, J. Workman, Anatoly Maksimchuk, X. Liu, U. Ellenberger, J.S. Coe, C.-Y. Chien, Donald P. Umstadter
Control Of Bright Picosecond X-Ray Emission From Intense Subpicosecond Laser-Plasma Interactions, J. Workman, Anatoly Maksimchuk, X. Liu, U. Ellenberger, J.S. Coe, C.-Y. Chien, Donald P. Umstadter
Donald Umstadter Publications
Using temporally and spectrally resolved diagnostics, we show that the pulse duration of laser-produced soft x rays emitted from solid targets can be controlled, permitting a reduction to as short as a few picoseconds. To enable this control, only a single parameter must be adjusted, namely, the intensity of the high-contrast ultrashort laser pulse (400 fs). These results are found to be in qualitative agreement with a simple model of radiation from a collisionally dominated atomic system.
Method And Apparatus For Generating Laser Plasma X-Rays, Donald P. Umstadter, Jonathan Workman, Anatoly Maksimchuk, Xinbing Liu
Method And Apparatus For Generating Laser Plasma X-Rays, Donald P. Umstadter, Jonathan Workman, Anatoly Maksimchuk, Xinbing Liu
Donald Umstadter Publications
The present information provides a system and an apparatus to produce x-rays from plasmas by focusing an intense, short duration optical pulse from a laser onto a target. The concentrated energy contained in the focused laser beam ionizes the target material, raising it to a temperature at which ions are produced in a chain reaction ionization, and x-rays are emitted when ions become de-excited (their electrons change energy level) or free electrons recombine with the ions in the plasma. The method comprises controlling pulse time duration of x-rays emitted from a plasma-forming target generating a beam of one or more …
Resonantly Laser-Driven Plasma Waves For Electron Acceleration, Donald P. Umstadter, J. Kim, Eric Esarey, E. Dodd, T. Neubert
Resonantly Laser-Driven Plasma Waves For Electron Acceleration, Donald P. Umstadter, J. Kim, Eric Esarey, E. Dodd, T. Neubert
Donald Umstadter Publications
A method for generating large-amplitude nonlinear plasma waves, which utilizes an optimized train of independently adjustable, intense laser pulses, is analyzed in one dimension both theoretically and numerically (using both Maxwell-fluid and particle-in-cell codes). Optimal pulse widths and interpulse spacings are computed for pulses with either square or finite-rise-time sine shapes. A resonant region of the plasma wave phase space is found where the plasma wave is driven most efficiently by the laser pulses. The width of this region, and thus the optimal finite-rise-time laser pulse width, was found to decrease with increasing background plasma density and plasma wave amplitude, …
Method For Generating A Plasma Wave To Accelerate Electrons, Donald P. Umstadter, Eric Esarey, Joon K. Kim
Method For Generating A Plasma Wave To Accelerate Electrons, Donald P. Umstadter, Eric Esarey, Joon K. Kim
Donald Umstadter Publications
The invention provides a method and apparatus for generating large amplitude nonlinear plasma waves, driven by an optimized train of independently adjustable, intense laser pulses. In the method, optimal pulse widths, interpulse spacing, and intensity profiles of each pulse are determined for each pulse in a series of pulses. A resonant region of the plasma wave phase space is found where the plasma wave is driven most efficiently by the laser pulses. The accelerator system of the invention comprises several parts: the laser system, also called beam source, which preferably comprises photo cathode electron source and RF-LINAC accelerator; electron photo-cathode …
Nonlinear Temporal Diffraction And Frequency Shifts Resulting From Pulse Shaping In Chirped-Pulse Amplification Systems, X Liu, R Wagner, Anatoly Maksimchuk, E Goodman, J Workman, Donald P. Umstadter, A Migus
Nonlinear Temporal Diffraction And Frequency Shifts Resulting From Pulse Shaping In Chirped-Pulse Amplification Systems, X Liu, R Wagner, Anatoly Maksimchuk, E Goodman, J Workman, Donald P. Umstadter, A Migus
Donald Umstadter Publications
We present experimental results of the amplif ication of strongly amplitude-modulated chirped pulses resulting from the coherent addition of two delayed short pulses. The nonlinearities in the amplifier chain induce a temporal diffraction resulting in prepulses and postpulses, in addition to the two main pulses when compressed. Simultaneously, temporal-resolved and spectral-resolved output pulses show that the prepulses and postpulses are blue shifted and red shifted, respectively, explaining the causality of the system.