A5037270334- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
- Advanced X-ray Imaging Techniques
- Laser Design and Applications
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Laser-Matter Interactions and Applications
- Planetary Science and Exploration
- Ionosphere and magnetosphere dynamics
- Dust and Plasma Wave Phenomena
- Solid State Laser Technologies
- Plasma Diagnostics and Applications
- Semiconductor materials and devices
- Astro and Planetary Science
- Traumatic Ocular and Foreign Body Injuries
- Acoustic Wave Resonator Technologies
- Earthquake Detection and Analysis
- Radiation Effects in Electronics
- Cyclone Separators and Fluid Dynamics
- GaN-based semiconductor devices and materials
- Photorefractive and Nonlinear Optics
- Advanced Radiotherapy Techniques
- Gas Dynamics and Kinetic Theory
The University of Texas at Austin
2015-2021
Auburn University
2011
RCA (United States)
1985-1987
We present an in-depth experimental-computational study of the parameters necessary to optimize a tunable, quasi-monoenergetic, efficient, low-background Compton backscattering (CBS) x-ray source that is based on self-aligned combination laser-plasma accelerator (LPA) and plasma mirror (PM). The main findings are (1) LPA driven in blowout regime by 30 TW, fs laser pulses produce not only high-quality, quasi-monoenergetic electron beam, but also relativistically intense (a0 ∼ 1) spent drive...
Get PDF Email Share with Facebook Tweet This Post on reddit LinkedIn Add to CiteULike Mendeley BibSonomy Citation Copy Text Donald E. Bossi, Jacob M. Hammer, and Joseph Shaw, "Optical properties of silicon oxynitride dielectric waveguides," Appl. Opt. 26, 609-611 (1987) Export BibTex Endnote (RIS) HTML Plain alert Save article
Relativistic electron beams driven by laser wakefield acceleration were utilized to produce ultrashort neutron sources. The experiment was carried out on the 38 fs, ∼0.5 J, 800 nm Ti:Sapphire in 10 TW UT3 lab at University of Texas Austin. target gas a high density pulsed jet composed 90% He and 10% N2. pulse with peak intensity 1.5 × 1018 W/cm2 interacted create cylindrical plasma channel 60 μm radius (FWHM) mm length (FWHM). Electron ∼80 pC Gaussian energy distribution centered 37 MeV...
We report an experimental-computational study of the optical properties plasma mirrors (PMs) at incident laser frequency when irradiated directly relativistic intensity (1e18 < I_0 1e19 W/cm^2) by near-normally (4 degree), high-contrast, 30 fs, 800 nm pulses. find that such PMs are highly reflective (0.6 to 0.8), and focus a significant fraction reflected light as large 10I_0 distance f small 25 microns from PM, provided pre-pulses do not exceed 1e14 W/cm^2 prior 20 ps before arrival main...
Dynamic wavelength stabilization of an AlGaAs diode laser has been demonstrated. The is butt coupled to a stripe-loaded optical waveguide which contains Bragg reflecting grating. pulsed with 50-ns-long, 25% duty cycle, 100% modulation depth pulses and the output observed remain at single wavelengths over peak current range 120–160 mA 15 °C temperature variations.
We demonstrate the first tunable Compton backscatter (CBS) x-ray source based on combination of a laser wakefield accelerator (LWFA) and plasma mirror (PM). A thin plastic film near gas jet exit efficiently retro-reflects LWFA driving pulse with relativistic intensity into oncoming electrons to produce CBS x-rays without detectable bremsstrahlung background. The X-ray central energy is from 75 KeV 200 by tuning e-beam energy. These have angular divergence 10-20 mrad, 50 % (FWHM) spread,...
We convert a GeV laser-plasma electron accelerator into compact femtosecond-pulsed $γ$-ray source by inserting $100 μ$m-thick glass plate $\sim3$ cm after the exit. With near-unity reliability, and requiring only crude alignment, this plasma mirror retro-reflected spent drive laser pulses (photon energy $\hbarω_L = 1.17$ eV) with $>50\%$ efficiency back onto trailing electrons (peak Lorentz factor $1000 < γ_e 4400$), creating an optical undulator that generated $\sim10^8 γ$-ray photons...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Edward Thomas, Ross Fisher, Joseph Shaw, Robert Jefferson, Mark Cianciosa, Jeremiah Williams; New Developments In Particle Image Velocimetry (PIV) For The Study Of Complex Plasmas. AIP Conf. Proc. 29 November 2011; 1397 (1): 122–125. https://doi.org/10.1063/1.3659752 Download citation file: Ris (Zotero)...
Previous work has demonstrated the use of a plasma mirror (PM), after laser-plasma accelerator (LPA), for generating Compton γ-rays by retro-reflecting spent laser pulse into just-accelerated electrons. Here, we investigate PM to stimulate backscatter (CBS) from Texas Petawatt (TPW) it driven cm-scale, GeV LPA. A comparative analysis between electron and CBS pointing divergence reveals strong agreement, shot-to-shot, suggesting reliable, non-invasive extension GeV-beam metrology. Our...
Volume Bragg grating (VBG) technology has been shown to improve spectral characteristics of the high-power laser diodes and arrays. We review recent advances in VBG that lead better performance as well improvements spatial brightness diode The applied manufacturing arrays suitable for beam combining achieve even higher brightness. approach involves fabrication elements with transverse chirp period. Wavelength tuning wavelength-shifted bar operation have demonstrated, which will spectrally...
We generate a collimated (<1mrad) beam of gamma rays that penetrate several centimeters lead by retro-reflecting petawatt laser pulse onto trailing ~2 GeV electrons with plasma mirror after driving laser-plasma accelerator.
We visualize plasma bubbles driven by 0.67 PW laser pulses in a of density ne≈5×1017cm−3 imaging Faraday rotation patterns imprinted on linearly polarized probe wavelength λpr=1.05 μm and duration τpr=2 or 1 ps that cross the bubble's path at right angles. When bubble captures accelerates tens to hundreds pC electron charges, we observe two parallel streaks length cτpr straddling drive pulse propagation axis, separated ∼45 μm, which polarization rotates 0.3° more than 5° opposite directions....
We have experimentally demonstrated ultrafast diagnostics to visualize the laser wakefield acceleration process in a single-shot mode. measured Faraday rotation of probe pulse due magnetic field induced by GeV electrons low-density plasmas. In addition, we improved temporal resolution Frequency Domain Streak Camera (FDSC) ∼10 fs broadening bandwidth beam, enabling visualization bubble dynamics. A prototype experiment using broad FDSC was performed.
We exploited the Faraday effect to imprint polarization shifts on a transverse probe that captured structure of GeV laser-plasma accelerator. Our measurements suggested plasma bubble diameter ≈ 50.8±10.1 μm.
We measure characteristics of plasma bubbles in GeV-class laser-plasma accelerators (LPAs) using Faraday rotation diagnostics. extend these techniques, previously demonstrated for LPAs atmospheric density plasmas (electron $n_e >10^{19}$ cm$^{-3}$), to low-density ($n_e \approx 5\times10^{17}$ which are $\sim 5$ times larger, and correspondingly easier visualize detail. The signals show $\approx 0.5^\circ$ streaks opposite sign separated by $\sim50$ $μ$m, consistent with bubble diameter;...
For the past decade, laser-plasma accelerators (LPAs) of millimeter to centimeter lengths have provided compact sources nearly mono-energetic, highly directional electron bunches, with energies as high 1 GeV. With advent petawatt scale lasers, these are now poised go well beyond GeV energies. In contrast large-scale accelerator facilities, LPA's will be devices, requiring spectrometers adapted unique properties LPA bunches. We report on a high-resolution spectrometer conditions.
We present experimental results of a method that measures high flux, MeV scale x-rays produced via Thomson backscatter (TBS) an intense laser pulse (a <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> ≈ 1) interacting with counter-propagating Laser wakefield acceleration (LWFA) electron bunch. predict the spectra broadband 50-100 TBS gamma-ray pulses in single shot by combining two diagnostics - pair-producing magnetic spectrometer and...