A5082562788- Laser-Plasma Interactions and Diagnostics
- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Laser-induced spectroscopy and plasma
- Plasma Diagnostics and Applications
- Laser-Matter Interactions and Applications
- Quantum chaos and dynamical systems
- Gyrotron and Vacuum Electronics Research
- Laser Design and Applications
- Ionosphere and magnetosphere dynamics
- Atomic and Molecular Physics
- Electromagnetic Simulation and Numerical Methods
- Pulsed Power Technology Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Dust and Plasma Wave Phenomena
- Superconducting Materials and Applications
- Semiconductor materials and devices
- Wildlife Ecology and Conservation
- Photonic Crystals and Applications
- Numerical methods for differential equations
- Particle Detector Development and Performance
- Distributed and Parallel Computing Systems
- Solar and Space Plasma Dynamics
- Advanced X-ray Imaging Techniques
Tech-X Corporation (United States)
2015-2024
University of Colorado Boulder
2015-2024
Baylor University
2024
University of Colorado System
1985-2024
Oregon State University
2022
University of Colorado Denver
2021
Fusion Academy
1981-2020
Fusion (United States)
1981-2020
Marist College
2019
Princeton Plasma Physics Laboratory
2018
Abstract: A stochastic computer model was used to examine the effects of varying degrees habitat fragmentation on dynamics a hypothetical population forest‐interior bid. The primary demographic parameter that influenced population's fecundity, which varied as function how far birds territory from an ecological edge. As our landscape became more fragmented proportion forest near edges increased geometrically, and overall fecundity dropped result. demonstrates impaired reproduction in is, by...
Plasma density gradients in a gas jet were used to control the wake phase velocity and trapping threshold laser wakefield accelerator, producing stable electron bunches with longitudinal transverse momentum spreads more than 10 times lower previous experiments (0.17 0.02 MeV/c FWHM, respectively) central momenta of 0.76+/-0.02 MeV/c. Transition radiation measurements combined simulations indicated that can be as accelerator injector produce beams 0.2 MeV/c-class spread at high energies.
Guiding-center theory provides the reduced dynamical equations for motion of charged particles in slowly varying electromagnetic fields, when fields have weak variations over a gyration radius (or gyroradius) space and period gyroperiod) time. Canonical noncanonical Hamiltonian formulations guiding-center offer improvements non-Hamiltonian formulations: possess Noether's theorem (hence invariants follow from symmetries), they preserve Poincar\'e (so that spurious attractors are prevented...
A slowly varying Hamiltonian with one degree of freedom and nearly closed orbits has an adiabatic invariant. This invariant is conserved to all orders in \ensuremath{\epsilon}, the slowness parameter, except for that cross a separatrix. The present work discusses change during this crossing process through order \ensuremath{\epsilon}. First, calculation presented. general and, hence, encompasses previous results specific cases. shown depend on maximum five parameters, which are functions...
1. We studied the effect of parasitism on snowshoe hare (Lepus americanus) survival through a field experiment that reduced natural burdens sublethal nematodes in free-ranging population. treated half hares each six study areas year-round with an anthelminthic drug, and other placebo. Potential interactive effects nutrition were examined by supplementing food supply three during two winters. Survival was measured radio-collaring total 612 mortality-sensitive transmitters monitoring daily...
A new method for the kinetic analysis of ponderomotive effects in collisionless plasma is presented. This involves application Lie-transform perturbation technique to Hamiltonian formulation Vlasov equation. Basically, a system, which high frequency oscillations are absent, found. In this system distribution function evolves according Hamiltonian, generalization potential. It shown that can easily be determined from well-known linear susceptibility. formalism used calculate several results....
When a parameter in the Hamiltonian of one-degree-of-freedom oscillator is slowly varied at rate $\ensuremath{\epsilon}$, an adiabatic invariant exists which conserved to all orders except on phase-space orbits cross separatrix. In present work, change due separatrix crossing given order $\ensuremath{\epsilon}$ for wide class systems. This result applied special case charged particle moving under influence electrostatic wave with varying amplitude and frequency.
The effectiveness and safety of orally administered verapamil was tested in 11 patients with frequent paroxysmal supraventricular tachycardia. In a 4-month randomized, double-blind, placebo-controlled trial, the frequency tachycardia fell from 0.3 +/- (mean SD) to 0.1 episodes per day by patient diary (p less than 0.05) 0.7 0.5 Holter monitor for placebo treatment periods, respectively. Verapamil caused decrease duration (in minutes day): 27 51 dairy, 67 111 Holter; verapamil, 3 diary, 1 2...
The origin of beam disparity in emittance and betatron oscillation orbits, out the polarization plane drive laser laser-plasma accelerators, is explained terms oscillations driven by field. As trapped electrons accelerate, they move forward interact with pulse. For bubble regime, a simple model presented to describe this interaction harmonic oscillator driving force from restoring plasma wake resulting plane, period approximately wavelength laser, increase that cause microbunching beam....
Reproduction was monitored during a 16-year study of snowshoe hare (Lepus americanus) populations near Rochester, Alberta. Pregnancy rate, ovulation and litter size changed markedly between successive litters within the breeding season; these parameters were thus further categorized by in our analyses. Most reproductive components varied significantly years; significant '10-year' periodicity dominant source this variation. The cyclic fluctuations broadly synchronous tended to precede...
Time-centered, hence second-order, methods for integrating the relativistic momentum of charged particles in an electromagnetic field are derived. A new method is found by averaging before use magnetic rotation term, and implementation presented that differs from Boris Push only calculating Lorentz factor. This shown to have same second-order accuracy time as splitting electric acceleration (Boris Push) velocity term (Vay's method) [J.-L. Vay, Phys. Plasmas 15, 056701 (2008)]. All three...
Abstract Plasma photocathode wakefield acceleration combines energy gains of tens GeV m −1 with generation ultralow emittance electron bunches, and opens a path towards 5D-brightness orders magnitude larger than state-of-the-art. This holds great promise for compact accelerator building blocks advanced light sources. However, an intrinsic by-product the enormous electric field gradients inherent to plasma accelerators is substantial correlated spread—an obstacle key applications such as...
This study aimed, through a field experiment, to test predictions from two hypotheses: (i) predation is factor limiting arctic hare (Lepus timidus) populations, and (ii) shifts hares when voles (Microtus Clethrionomys) decline scarcity. Our approach was compare demographic characteristics of populations on large islands (Rånön, 2350 ha, Bergön, 1800 ha) in the northern Baltic, where foxes (Vulpes vulpes) martens (Martes martes) were alternately present normal numbers or reduced by snaring...
We have obtained an exact, simple, and general relation between the second-order Hamiltonian, representing ponderomotive force on oscillation center of a particle in high-frequency field, standard linear Vlasov susceptibility.
Sources of high-energy photons have important applications in almost all areas research. However, the photon flux and intensity existing sources is strongly limited for energies above a few hundred keV. Here we show that high-current ultrarelativistic electron beam interacting with multiple submicrometer-thick conducting foils can undergo strong self-focusing accompanied by efficient emission gamma-ray synchrotron photons. Physically, originate from interaction near-field transition...