4,258 research outputs found
Determining pitch-angle diffusion coefficients from test particle simulations
No full textThe transport and acceleration of charged particles in turbulent media are topics of great interest in space physics and interstellar astrophysics. These processes are dominated by the scattering of particles off magnetic irregularities. The scattering process itself is usually described by small-angle scattering, with the pitch-angle coefficient playing a major role. Since the diffusion coefficient can be determined analytically only for the approximation of quasilinear theory, the determination of this coefficient from numerical simulations has become more important. So far these simulations have yielded particle tracks for small-scale scattering, which can then be interpreted using the running diffusion coefficients. This method has a limited range of validity. This paper presents two new methods that allow for the calculation of the pitch-angle diffusion coefficient from numerical simulations. These methods no longer analyze particle trajectories and instead examine the change of particle distribution functions. It is shown that these methods provide better resolved results and allow for the analysis of strong turbulence. The application of these methods to Monte Carlo simulations of particle scattering and hybrid MHD-particle simulations is presented. Both analysis methods are able to recover the diffusion coefficients used as input for the Monte Carlo simulations and provide better results in MHD simulations, especially for stronger turbulenc
Adrian Caesar speaking at Alex Miller author: A Celebration, held at the National Library, Canberra, 30 October 2011 /
No full textTitle from information supplied by photographer.; Part of the collection: Alex Miller author: A Celebration, held at the National Library of Australia theatre, 30 October 2011.; Mode of access: Online.; Photographed by a staff member of the National Library of Australia
[Letter from Alex Bradford to Lieutenant and Mrs. Ray Starner - November 4, 1940]
No full textLetter from Alex Bradford to Lieutenant and Mrs. Ray Starner describing the the current state of affairs that the author was experiencing, including: the London blitz, the moral of the troops on the ground, and the collective company of men opposing the Nazi regime
Alex Haley, author
No full textExamines the life and achievements of Alex Haley, celebrated author of "Roots" and other writings, discussing his life and literary career, as well as his obsession with researching his family's history
Description by author Alex Irvine of his recent participation in the San Diego C
No full textDescription by author Alex Irvine of his recent participation in the San Diego Comic-Con, one of the largest conferences of comic/media/book producers and consumers. Irvine was there to promote his new fiction book, One King, One Soldier, published by Del Rey
Recovery through contradiction?
No full textWith this new drug strategy, the circle has turned. It was a Conservative government
that introduced the first drug strategy, Tackling Drugs Together, in 1995. This aimed
to reduce drug related crime, protect young people and reduce health harms by
discouraging drug use. It was criticised at the time for having unrealistic, intangible
aims and for not providing the necessary funding. New Labour’s strategies introduced
increasingly specific targets and massively expanded the funding of treatment. This
new Coalition strategy has no targets and provides no new funding
Alex Miller signing books at the National Library of Australia, Canberra, 30 October 2011 /
No full textTitle from information supplied by photographer.; Part of the collection: Alex Miller author: A Celebration, held at the National Library of Australia theatre, 30 October 2011.; Mode of access: Online.; Photographed by a staff member of the National Library of Australia
Alex Miller taking questions at the National Library of Australia, Canberra, 30 October 2011 /
No full textTitle from information supplied by photographer.; Part of the collection: Alex Miller author: A Celebration, held at the National Library of Australia theatre, 30 October 2011.; Mode of access: Online.; Photographed by a staff member of the National Library of Australia
Alex Miller and Genevieve Jacobs at the National Library of Australia, Canberra, 30 October 2011 /
No full textTitle from information supplied by photographer.; Part of the collection: Alex Miller author: A Celebration, held at the National Library of Australia theatre, 30 October 2011.; Mode of access: Online.; Photographed by a staff member of the National Library of Australia
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