With the aim of developing the application of neutron Compton scattering (NCS) to molecular systems of biophysical interest, we are using the Compton spectrometer EVS at ISIS to characterize the momentum distribution of protons in peptide groups. Neutron Compton scattering from selectively deuterated acetanilide A misconception in the literature on Compton scattering of circularly polarized beams is corrected and recorded.« less In addition, as discussed in the body of the paper, many of the results allow easy scaling estimates to be made of the expected spectrum. ![]() ![]() The method is used to predict the energy spectrum of radiation passing through an aperture for the proposed Old Dominion University inverse Compton source. Such anmore » approach has the obvious advantage that it is easily integrated with a particle distribution generated by particle tracking, allowing precise calculations of spectra for realistic particle distributions in collision. By performing the proper Lorentz transformation of the Klein-Nishina scattering cross section, a spectrum calculation can be created which allows the electron beam energy spread and emittance effects on the spectrum to be accurately calculated, essentially by summing over the emission of each individual electron. In this paper, this problem has been reconsidered within a linear plane wave model for the incident laser beam. Previous work on calculating energy spectra from Compton scattering events has either neglected considering the pulsed structure of the incident laser beam, or has calculated these effects in an approximate way subject to criticism. Laser pulsing in linear Compton scattering We conclude that the formulae by Guilbert and the exact quantum mechanical formulae yield practically the same RFs for gas temperatures relevant to the atmospheres of X-ray bursting neutron stars, T ≤ 108 K. Our formulae are also useful to study the Compton scattering of unpolarized microwave background radiation in hot intracluster gas and the Sunyaev-Zeldovich effect. Sample computations of the Compton scattering RFs in thermal plasma were done for temperatures corresponding to the atmospheres of bursting neutron stars and hot intergalactic medium. The exact method by Nagirner & Poutanen was numerically compared to all other algorithms in a very wide spectral range from hard X-rays to radio waves. We have also organized four existing algorithms for the RF computations into a unified form ready to use in radiative transfer and model atmosphere codes. This corrected RF was used in the series of papers on model atmosphere computations of hot neutron stars. The principal aim of this paper is the presentation of the RF by Guilbert, which is corrected for the computational errors in the original paper. We collected here a set of numerical expressions of the Compton scattering redistribution functions (RFs) for unpolarized radiation, which are more exact than the widely used Kompaneets equation. Należyty, M.Ĭompton scattering is the dominant opacity source in hot neutron stars, accretion discs around black holes and hot coronae. On the Compton scattering redistribution function in plasma This work is supported by the European Research Council Grant (ERC- 2015-AdG 695088) and the Fundao para a Céncia e Tecnologia (Bolsa de Investigao PD/BD/114323/2016). ![]() and the numerical solution of the linear Kompaneets equation and good agreement is found between the simulations and the theoretical models. We present benchmarks of the code against the analytical results of Blumenthal et al. The algorithm accounts for the stochastic nature of Compton scattering reproducing without approximations the exchange of energy between photons and unbound charged species. ![]() We present the implementation of a novel module, embedded in the self-consistent framework of the PIC code OSIRIS 4.0, capable of simulating Compton scattering from first principles and that is fully integrated with the self-consistent plasma dynamics. In these scenarios, Compton scattering is coupled with self-consistent mechanisms such as pair cascades. Compton scattering collision module for OSIRISĭel Gaudio, Fabrizio Grismayer, Thomas Fonseca, Ricardo Silva, LuÃsĬompton scattering plays a fundamental role in a variety of different astrophysical environments, such as at the gaps of pulsars and the stagnation surface of black holes.
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