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Full-Text Articles in Physics
Relativistic And Radiative Corrections To The Mollow Spectrum, Jorg Evers, Ulrich D. Jentschura, Christoph H. Keitel
Relativistic And Radiative Corrections To The Mollow Spectrum, Jorg Evers, Ulrich D. Jentschura, Christoph H. Keitel
Physics Faculty Research & Creative Works
The incoherent inelastic part of the resonance fluorescence spectrum of a laser-driven atom is known as the Mollow spectrum [B. R. Mollow, Phys. Rev. 188, 1969 (1969)]. Starting from this level of description, we discuss theoretical foundations of high-precision spectroscopy using the resonance fluorescence light of strongly laser-driven atoms. Specifically, we evaluate the leading relativistic and radiative corrections to the Mollow spectrum, up to the relative orders of ( Z α )2 and α ( Z α )2 , respectively, and Bloch-Siegert shifts as well as stimulated radiative corrections involving off-resonant virtual states. Complete results are provided for …
Simulations Of Resonant Alfvén Waves Generated By Artificial Hf Heating Of The Auroral Ionosphere, D Pokhotelov, W Lotko, A V. Streltsov
Simulations Of Resonant Alfvén Waves Generated By Artificial Hf Heating Of The Auroral Ionosphere, D Pokhotelov, W Lotko, A V. Streltsov
Dartmouth Scholarship
Numerical two-dimensional two-fluid MHD sim- ulations of dynamic magnetosphere-ionosphere (MI) cou- pling have been performed to model the effects imposed on the auroral ionosphere by a powerful HF radio wave trans- mitter. The simulations demonstrate that modifications of the ionospheric plasma temperature and recombination due to artificial heating may trigger the ionospheric feedback in- stability when the coupled MI system is close to the state of marginal stability. The linear dispersion analysis of MI coupling has been performed to find the favorable conditions for marginal stability of the system. The development of the ionospheric feedback instability leads to the generation …
A Dunking Bird Of The Second Kind, Nadine Abraham, Peter Palffy-Muhoray
A Dunking Bird Of The Second Kind, Nadine Abraham, Peter Palffy-Muhoray
Peter Palffy-Muhoray
The conventional dunking bird is a heat engine that relies on the temperature difference between the head and the tail of the bird for its operation. We describe a new type of dunking bird that is not a heat engine, but one that directly uses the chemical potential difference between liquid water and its vapor.
High-Latitude Propagation Studies Using A Meridional Chain Of Lf/Mf/Hf Receivers, J Labelle
High-Latitude Propagation Studies Using A Meridional Chain Of Lf/Mf/Hf Receivers, J Labelle
Dartmouth Scholarship
For over a decade, Dartmouth College has oper- ated programmable radio receivers at multiple high-latitude sites covering the frequency range 100–5000 kHz with about a 1-s resolution. Besides detecting radio emissions of auro- ral origin, these receivers record characteristics of the iono- spheric propagation of natural and man-made signals, docu- menting well-known effects, such as the diurnal variation in the propagation characteristics of short and long waves, and also revealing more subtle effects. For example, at auroral zone sites in equinoctial conditions, the amplitudes of dis- tant transmissions on MF/HF frequencies are often enhanced by a few dB just before …
Limits To Performance Improvement Provided By Balanced Interferometers And Balanced Detection In Oct/Ocm Instruments, David Liao, Adam E. Pivonka, Brendan R. Haberle, Daniel C. Petersen, Barbara M. Hoeling, Richard C. Haskell
Limits To Performance Improvement Provided By Balanced Interferometers And Balanced Detection In Oct/Ocm Instruments, David Liao, Adam E. Pivonka, Brendan R. Haberle, Daniel C. Petersen, Barbara M. Hoeling, Richard C. Haskell
All HMC Faculty Publications and Research
We compare the dynamic range of OCT/OCM instruments configured with unbalanced interferometers, e.g., Michelson interferometers, with that of instruments utilizing balanced interferometers and balanced photodetection. We define the dynamic range (DR) as the ratio of the maximum fringe amplitude achieved with a highly reflecting surface to the root-mean-square (rms) noise. Balanced systems achieve a dynamic range 2.5 times higher than that of a Michelson interferometer, enabling an image acquisition speed roughly 6 times faster. This maximum improvement occurs at light source powers of a few milliwatts. At light source powers higher than 30 mW, the advantage in acquisition speed of …
Superferromagnetic Domain State Dynamics In Discontinuous Cofe/Al2o3, Christian Binek
Superferromagnetic Domain State Dynamics In Discontinuous Cofe/Al2o3, Christian Binek
Christian Binek Publications
Magnetization hysteresis and AC susceptibility measurements were performed on the discontinuous metal–insulator multilayer [Co80Fe20(1.4 nm)/Al2O3(3 nm)]10. CoFe forms ferromagnetic single-previous domain term particles being embedded in the Al2O3 matrix. Due to strong dipolar inter-particle interactions a “previous superferromagnetic term” correlation of particle moments was previously stated. The dynamical magnetic properties of the superferromagnet can be understood in the framework of previous domain term wall motion in an impure ferromagnet. Kinetic simulations are employed, which are based on field and temperature-dependent previous domain term wall velocities. The magnetization hysteresis as well as the AC susceptibility, χ′−iχ′′, are calculated and compared to …
A Study Of Pc-5 Ulf Oscillations, M K. Hudson, R E. Denton, M R. Lessard, E G. Miftakhova, R R. Anderson
A Study Of Pc-5 Ulf Oscillations, M K. Hudson, R E. Denton, M R. Lessard, E G. Miftakhova, R R. Anderson
Dartmouth Scholarship
A study of Pc-5 magnetic pulsations using data from the Combined Release and Radiation Effects Satellite (CRRES) was carried out. Three-component dynamic mag- netic field spectrograms have been used to survey ULF pul- sation activity for the approximate fourteen month lifetime of CRRES. Two-hour panels of dynamic spectra were exam- ined to find events which fall into two basic categories: 1) toroidal modes (fundamental and harmonic resonances) and 2) poloidal modes, which include compressional oscillations. The occurence rates were determined as a function of L value and local time. The main result is a comparable probabil- ity of occurence of …