A5068549476- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Advanced X-ray Imaging Techniques
- Laser Design and Applications
- Diamond and Carbon-based Materials Research
- Terahertz technology and applications
- High-pressure geophysics and materials
- Particle Accelerators and Free-Electron Lasers
- Laser-Matter Interactions and Applications
- DNA and Nucleic Acid Chemistry
- Nuclear Physics and Applications
- Solid State Laser Technologies
- Bacterial Identification and Susceptibility Testing
- Color Science and Applications
- Plasma Diagnostics and Applications
- Copper-based nanomaterials and applications
- Photonic and Optical Devices
- Advanced biosensing and bioanalysis techniques
- Chalcogenide Semiconductor Thin Films
- Crystal Structures and Properties
- RNA Interference and Gene Delivery
- Spectroscopy and Quantum Chemical Studies
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Molecular Junctions and Nanostructures
Optical Sciences (United States)
2020-2025
University of Michigan
2020-2025
Michigan United
2021-2023
University of Tübingen
2017
University of Konstanz
2007-2008
Abstract Laser wakefield accelerators promise to revolutionize many areas of accelerator science. However, one the greatest challenges their widespread adoption is difficulty in control and optimization outputs due coupling between input parameters dynamic evolution accelerating structure. Here, we use machine learning techniques automate a 100 MeV-scale accelerator, which optimized its by simultaneously varying up six including spectral spatial phase laser plasma density length. Most...
We have designed a new filter pack array to measure angular variations in x-ray spectra during single shot. The was composed of repeating identical columns aluminum and copper filters varying thicknesses. These were located at different positions the spectrum each corresponding angle. This utilized an experiment energy evolution betatron x rays laser wakefield accelerator by curving with transverse density gradient, streaking across front charge-coupled device (CCD) camera. After subtracting...
We simultaneously surface-functionalize PbS nanocrystals with Cu 4,4',4'',4'''-tetraaminophthalocyanine and assemble this hybrid material into macroscopic monolayers. Electron microscopy X-ray scattering reveal a granular mesocrystalline structure strong coherence between the atomic lattice superlattice of within each domain. Terahertz spectroscopy field-effect transistor measurements indicate efficient coupling holes throughout thin film, in conjunction pronounced photoresponse. demonstrate...
Computer models of intense, laser-driven ion acceleration require expensive particle-in-cell simulations that may struggle to capture all the multi-scale, multi-dimensional physics involved at reasonable costs. Explored is an approach ameliorate this deficiency using a multi-fidelity framework can incorporate physical trends and phenomena different levels. As basis for study, ensemble approximately 8000 1D was generated buttress separate ensembles hundreds higher fidelity 2D simulations....
The B to A conformational transition of highly oriented DNA films due a hydration change is observed with time-domain terahertz spectroscopy. Wet-spun calf thymus and salmon are investigated for different film thicknesses polarizations the radiation relative orientation. clear polarization dependence observed. Asynchronous optical sampling allows recording absorption background spectra in few 10s, permitting tracking dehydration dynamics on time scale minutes. observation phase corroborated by Raman
Intense x-ray pulses can cause the non-thermal structural transformation of diamond. At SACLA XFEL facility, pump triggered this phase transition, and probe produced diffraction patterns. Time delays were observed from 0 to 250 fs, dose varied 0.9 8.0 eV/atom. The intensity (111), (220), (311) peaks decreased with time, indicating a disordering crystal lattice. From Debye-Waller analysis, rms atomic displacements perpendicular (111) planes be significantly larger than those (220) or planes....
The generation of low emittance electron beams from laser-driven wakefields is crucial for the development compact x-ray sources. Here, we show new results injection and acceleration quasimonoenergetic in amplitude experimentally using simulations. This achieved by two laser pulses decoupling wakefield trapping via ionization injection. duration, which affects beam charge energy spread, found to be tunable adjusting relative pulse delay. By changing polarization injector pulse, reducing...
We present a terahertz time-domain spectrometer with large bandwidth, high spectral resolution, and sensitivity. A bandwidth of larger than 3 THz, resolution 1 GHz sensitivity 60 dB dynamic range are achieved in data acquisition time less s. The is based on high-speed asynchronous optical sampling which employs two femtosecond lasers repetition rate stabilized to 10 kHz off-set the rates employing frequency shifter. This technique opens new perspectives perform high-resolution THz...
X-ray Free Electron Laser (XFEL) radiation may transform diamond into graphite. Two pulses were used; the first as pump to trigger phase transition and second probe performing diffraction. The experiment was performed at SACLA XFEL facility beamline 3 experimental hutch 5. samples polycrystalline diamond. photon energies 7 10.5 keV, respectively, delay between varied from 0 286 fs. To provide a range of energy densities, focus adjusted 150 nm 1 um. (111), (220) (311) diffraction peaks...
<title>Abstract</title> Laser-wakefield accelerated electron beams have been demonstrated to be a viable alternative those produced by radio-frequency systems, with unique characteristics including intrinsic femtosecond-scale duration and micron-scale source size. In addition, they present the practical advantage of generally compact cost-effective setup inherently synchronsed high-power laser. The rapid progress experienced these accelerators is now posing question as whether could included...
Optimisation of betatron X-rays and their applications, SPIE Optics + Optoelectronics, 2021