Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Interactions Of Ultrashort, Ultrahigh Intensity Laser Pulses With Underdense Plasmas, Xiaofang Wang, Wei Yu, Sterling Backus, Margaret Murnane, Henry Kapteyn, Donald P. Umstadter
Interactions Of Ultrashort, Ultrahigh Intensity Laser Pulses With Underdense Plasmas, Xiaofang Wang, Wei Yu, Sterling Backus, Margaret Murnane, Henry Kapteyn, Donald P. Umstadter
Donald Umstadter Publications
The interactions of ultraintense laser pulses with underdense plasmas are studied in a new regime in which the longitudinal spatial extent of the pulse duration is close to both the laser focal spot size and the plasma wavelength.
Laser Acceleration Of Protons From Thin Film Targets, K. Flippo, Sudeep Banerjee, V. Yu. Bychenkov, S. Gu, Anatoly Maksimchuk, G. Mourou, K. Nemoto, Donald P. Umstadter
Laser Acceleration Of Protons From Thin Film Targets, K. Flippo, Sudeep Banerjee, V. Yu. Bychenkov, S. Gu, Anatoly Maksimchuk, G. Mourou, K. Nemoto, Donald P. Umstadter
Donald Umstadter Publications
A collimated beam of fast protons, with energies as high as 10 MeV and total number of 109, confined in a cone angle of 40°±10° has been observed when a 10 TW laser with frequencies either ω0 (corresponding to 1 μm) or 2ω0 was focused to an intensity of a few times 1018 W/cm2 on the surface of a thin film target. The protons, which originate from impurities on the front side of the target, are accelerated over a region extending into the target and exit out the backside in a direction normal to …
Status Of The Lilac Experiment, N. Saleh, P. Han, C. Keppel, P. Gueye, V Yanovsky, Donald P. Umstadter
Status Of The Lilac Experiment, N. Saleh, P. Han, C. Keppel, P. Gueye, V Yanovsky, Donald P. Umstadter
Donald Umstadter Publications
We present the status of the LILAC experiment [1], including results on the propagation of 30-fs duration laser pulses in plasmas of the requisite density, and measurements of the dark current [2]. We also discuss the status of a laser upgrade, an electron beam line and plans for the future.
Coherent Control Of Stimulated Raman Scattering Using Chirped Laser Pulses, Evan S. Dodd, Donald P. Umstadter
Coherent Control Of Stimulated Raman Scattering Using Chirped Laser Pulses, Evan S. Dodd, Donald P. Umstadter
Donald Umstadter Publications
A novel method for the control of stimulated Raman scattering and hot electron production in short-pulse laser-plasma interactions is proposed. It relies on the use of a linear frequency chirp in nonbandwidth limited pulses. Theoretical calculations show that a 12% bandwidth will eliminate Raman forward scattering for a plasma density that is 1% of the critical density. The predicted changes to the growth rate are confirmed in two-dimensional particle-in-cell simulations. Relevance to areas of current research is also discussed.
An All Optical Laser Wakefield Electron Injector, Donald P. Umstadter
An All Optical Laser Wakefield Electron Injector, Donald P. Umstadter
Donald Umstadter Publications
The personnel who were supported by the grant included the P.I. (Prof. Umstadter), several research scientists (A. Maksimchuk and V. Yanovsky), a postdoc (P. Zhang) and several graduate and undergraduate students. Although there were several setbacks in developing the novel laser technology required to produce a monoenergetic beam of electrons from an all-optical accelerator, several important steps were taken towards reaching that ultimate goal. The most important outcome of this project was that we demonstrated the principle of optical control of laser accelerators, namely, that one laser pulse could modify the properties (e.g., emittance and electron number) of an electron …
Fast Ignitor Concept With Light Ions, V. Yu. Bychenkov, W. Rozmus, Anatoly Maksimchuk, Donald Umstadter, C.E. Capjack
Fast Ignitor Concept With Light Ions, V. Yu. Bychenkov, W. Rozmus, Anatoly Maksimchuk, Donald Umstadter, C.E. Capjack
Donald Umstadter Publications
A short-laser-pulse driven ion flux is examined as a fast ignitor candidate for inertial confinement fusion. Ion ranges in a hot precompressed fuel are studied. The ion energy and the corresponding intensity of a short laser pulse are estimated for the optimum ion range and ion energy density flux. It is shown that a lightion beam triggered by a few-hundreds-kJ laser at intensities of ~1021W/cm2 is relevant to the fast ignitor scenario.
Laser-Triggered Ion Acceleration And Table Top Isotope Production, K. Nemoto, Anatoly Maksimchuk, Sudeep Banerjee, K. Flippo, G. Mourou, Donald P. Umstadter, B. Yu. Bychenkov
Laser-Triggered Ion Acceleration And Table Top Isotope Production, K. Nemoto, Anatoly Maksimchuk, Sudeep Banerjee, K. Flippo, G. Mourou, Donald P. Umstadter, B. Yu. Bychenkov
Donald Umstadter Publications
We have observed deuterons accelerated to energies of about 2 MeV in the interaction of relativistically intense 10 TW, 400 fs laser pulse with a thin layer of deuterated polystyrene deposited on Mylar film. These high-energy deuterons were directed to the boron sample, where they produced ~105 atoms of positron active isotope 11C from the reaction 10B(d,n)11C. The activation results suggest that deuterons were accelerated from the front surface of the target.