Synchrotron radiation

About: Synchrotron radiation is a research topic. Over the lifetime, 14639 publications have been published within this topic receiving 244775 citations. The topic is also known as: magnetobremsstrahlung radiation & Synchrotron Radiation.

Helicity switching of circularly polarized undulator radiation by local orbit bumps

Abstract: Helicity switching of circularly polarized undulator radiation provides a valuable tool in synchrotron radiation experiments, particularly in the study of circular dichroism. At SPring-8, we have developed a helicity switching system by means of selecting radiation from two helical undulators. Right and left circular photon beams are alternately supplied to the beamline using electron beam orbit bumps. Instead of reversing the magnetic field applied to a sample, helicity switched light was used in magnetic circular dichroism measurements and the measuring time was reduced by 1 3 .

Transfer of polarized radiation in self-absorbed synchrotron sources. II - Treatment of inhomogeneous media and calculation of emergent polarization

Abstract: As an extension of previous treatments of polarized radiation transfer in homogeneous synchrotron sources, a transfer procedure is derived, based on the coupled-wave formulation, which allows consideration of inhomogeneous sources. It is shown that plasma characteristic wave eccentricities in a source must be fairly large unless Faraday rotation per absorption depth is very large, and that coupling between characteristic waves can be strong in inhomogeneous self-absorbed sources. Calculations are made of the polarized radiation emergent from a source with a boundary of finite thickness. It is found that neglect of propagation effects in the source boundary introduces no significant errors at optically thin frequencies, but that below the self-absorption turnover the emergent polarization may depend significantly upon such effects. In particular, the sign of the circular polarization and the linear polarization position angle depend upon the absorption depth in the boundary region.

A comparison of the radio data and model calculations of Jupiter's synchrotron radiation, 1. The high energy electron distribution in Jupiter's inner magnetosphere

Abstract: An electron distribution in Jupiter's magnetosphere as a function of energy, pitch angle and spatial coordinates is derived from a comparison of model calculations of the planet's synchrotron radiation with the radio data; the distribution is consistent with the information available from the Pioneer data. The model calculations are based upon the magnetic field configurations as derived by Acuna and Ness [1976a, b] (the O4 model) and Davis, Jones and Smith [quoted in Smith and Gulkis, 1979] (the P11 (3,2) A model) from the Pioneer data. The electrons are assumed to diffuse radially inwards with a rate D=3 × 10−9 L³ s−1 (where L is McIlwain's value) and have a lifetime against local losses τ=4 × 106 L−0.6 s, in agreement with the values derived by Goertz et al. [1979] from the Pioneer data. The number density of electrons with E ≥20 MeV at L=3 is in agreement with the values measured by the spacecraft, but the energy distribution appears to be much flatter. Electrons are absorbed with survival probabilities of ∼0.5 diffusing inwardly past Amalthea's sweeping region (for 20-MeV electrons) and ∼0.35 past the ring, respectively. An energy dependent pitch angle scattering is found to occur at Amalthea's orbit, and there is no pitch angle scattering present near the ring.

Modeling the early multiwavelength emission in GRB130427A

Abstract: One of the most powerful gamma-ray bursts, GRB 130427A was swiftly detected from GeV $\gamma$-rays to optical wavelengths. In the GeV band, the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope observed the highest-energy photon ever recorded of 95 GeV, and a bright peak in the early phase followed by emission temporally extended for more than 20 hours. In the optical band, a bright flash with a magnitude of $7.03\pm 0.03$ in the time interval from 9.31 s to 19.31 s after the trigger was reported by RAPTOR in r-band. We study the origin of the GeV $\gamma$-ray emission, using the multiwavelength observation detected in X-ray and optical bands. The origin of the temporally extended LAT, X-ray and optical flux is naturally interpreted as synchrotron radiation and the 95-GeV photon and the integral flux upper limits placed by the HAWC observatory are consistent with synchrotron self-Compton from an adiabatic forward shock propagating into the stellar wind of its progenitor. The extreme LAT peak and the bright optical flash are explained through synchrotron self-Compton and synchrotron emission from the reverse shock, respectively, when the ejecta evolves in thick-shell regime and carries a significant magnetic field.

Nonstationariness of spectra of young sources of nonthermal radio emission

Abstract: The effect of various modes of energy losses by relativistic electrons on the spectrum of sources of nonthermal cosmic radio-frequency emission is considered, as well as the effect of the systematic and stochastic acceleration of relativistic electrons. Energy spectra are found for various combnations of energy buildup and loss processes, and the time variation of the spectra is studied. The expected synchrotron radiation spectra are obtained, and the variation of these spectra during the evolution of radio sources is investigated. (auth)