Emission Of Synchrotron Radiation Research Articles

Using 3D Finite Element Method (FEM) as an Optothermal Human Cancer Cells, Tissues and Tumors Treatment in Simulation of Interaction of Synchrotron Radiation Emission as a Function of the Beam Energy and Uranium Nanoparticles

Using 3D Finite Element Method (FEM) as an Optothermal Human Cancer Cells, Tissues and Tumors Treatment in Simulation of Interaction of Synchrotron Radiation Emission as a Function of the Beam Energy and Uranium Nanoparticles

Simulation of Interaction of Synchrotron Radiation Emission as A Function of the Beam Energy and Plutonium Nanoparticles Using 3d Finite Element Method (Fem) as an Optothermal Human Cancer Cells, Tiss

In the current study, thermoplasmonic characteristics of Plutonium nanoparticles with spherical, core–shell and rod shapes are investigated. In order to investigate these characteristics, interaction of synchrotron radiation emission as a function of the beam energy and Plutonium nanoparticles were simulated using 3D finite element method. Firstly, absorption and extinction cross sections were calculated. Then, increases in temperature due to synchrotron radiation emission as a function of the beam energy absorption were calculated in Plutonium nanoparticles by solving heat equation. The obtained results show that Plutonium nanorods are more appropriate option for using in optothermal human cancer cells, tissues and tumors treatment method.

Tidal Disruption Events in Active Galactic Nuclei

Abstract A fraction of tidal disruption events (TDEs) occur in active galactic nuclei (AGNs) whose black holes possess accretion disks; these TDEs can be confused with common AGN flares. The disruption itself is unaffected by the disk, but the evolution of the bound debris stream is modified by its collision with the disk when it returns to pericenter. The outcome of the collision is largely determined by the ratio of the stream mass current to the azimuthal mass current of the disk rotating underneath the stream footprint, which in turns depends on the mass and luminosity of the AGN. To characterize TDEs in AGNs, we simulated a suite of stream–disk collisions with various mass current ratios. The collision excites shocks in the disk, leading to inflow and energy dissipation orders of magnitude above Eddington; however, much of the radiation is trapped in the inflow and advected into the black hole, so the actual bolometric luminosity may be closer to Eddington. The emergent spectrum may not be thermal, TDE-like, or AGN-like. The rapid inflow causes the disk interior to the impact point to be depleted within a fraction of the mass return time. If the stream is heavy enough to penetrate the disk, part of the outgoing material eventually hits the disk again, dissipating its kinetic energy in the second collision; another part becomes unbound, emitting synchrotron radiation as it shocks with surrounding gas.

Gamma-ray emission from wakefield-accelerated electrons wiggling in a laser field

Ultra-fast synchrotron radiation emission can arise from the transverse betatron motion of an electron in a laser plasma wakefield, and the radiation spectral peak is limited to tens of keV. Here, we present a new method for achieving high-energy radiation via accelerated electrons wiggling in an additional laser field whose intensity is one order of magnitude higher than that for the self-generated transverse field of the bubble, resulting in an equivalent wiggler strength parameter K increase of approximately twenty times. By calculating synchrotron radiation, we acquired a peak brightness for the case of the laser wiggler field of 1.2 × 1023 ph/s/mrad2/mm2/0.1%BW at 1 MeV. Such a high brilliance and ultra-fast gamma-ray source could be applied to time-resolved probing of dense materials and the production of medical radioisotopes.

Proton Acceleration in Colliding Stellar Wind Binaries

Abstract The interaction between the strong winds in stellar colliding-wind binary (CWB) systems produces two shock fronts, delimiting the wind-collision region (WCR). There, particles are expected to be accelerated mainly via diffusive shock acceleration. We investigate the injection and acceleration of protons in typical CWB systems by means of Monte Carlo simulations, with both a test-particle approach and a nonlinear method modeling a shock locally modified by the backreaction of the accelerated protons. We use magnetohydrodynamic simulations to determine the background plasma in the WCR and its vicinity. This allows us to consider particle acceleration at both shocks, on either side of the WCR, with a realistic large-scale magnetic field. We highlight the possible effects of particle acceleration on the local shock profiles at the WCR. We include the effect of magnetic field amplification, due to resonant-streaming instability, and compare results without and with the backreaction of the accelerated protons. In the latter case, we find a lower flux of the nonthermal proton population and a considerable magnetic field amplification. This would significantly increase the synchrotron losses of relativistic electrons accelerated in CWB systems, lowering the maximal energy they can reach and strongly reducing the inverse Compton fluxes. As a result, γ-rays from CWBs would be predominantly due to the decay of neutral pions produced in nucleon–nucleon collisions. This might provide a way to explain why, in the vast majority of cases, CWB systems have not been identified as γ-ray sources, although they emit synchrotron radiation.

Human Cancer Cells, Tissues and Tumors Treatment Using Dysprosium Nanoparticles

In present study, thermoplasmonic characteristics of dysprosium nanoparticles with spherical, coreshell and rod shapes are investigated. In order to investigate these characteristics, interaction of synchrotron radiation emission as a function of the beam energy and dysprosium nanoparticles were simulated using 3D finite element method. Firstly, absorption and extinction cross-sections were calculated. Then, increases in temperature due to synchrotron radiation emission as a function of the beam energy absorption were calculated in dysprosium nanoparticles by solving heat equation. The results show that the dysprosium nanorods are more appropriate option for using in optothermal human cancer cells, tissues and tumors treatment method.

Computational approach to interaction between synchrotron radiation emission as a function of the beam energy and ruthenium nanoparticles in human gum cancer cells, tissues and tumors treatment

Computational approach to interaction between synchrotron radiation emission as a function of the beam energy and ruthenium nanoparticles in human gum cancer cells, tissues and tumors treatment

Effectiveness of Einsteinium Nanoparticles in Optothermal Human Cancer Cells, Tissues and Tumors Treatment under Synchrotron Radiation

In the current study, thermoplasmonic characteristics of Einsteinium nanoparticles with spherical, core-shell and rod shapes are investigated. In order to investigate these characteristics, interaction of synchrotron radiation emission as a function of the beam energy and Einsteinium nanoparticles were simulated using 3D finite element method. Firstly, absorption and extinction cross sections were calculated. Then, increases in temperature due to synchrotron radiation emission as a function of the beam energy absorption were calculated in Einsteinium nanoparticles by solving heat equation. The obtained results show that Einsteinium nanorods are more appropriate option for using in optothermal human cancer cells, tissues and tumors treatment method. Scanning Electron Microscope (SEM) image of Einsteinium nanoparticles with 50000x zoom.

KALYPSO: Linear array detector for high-repetition rate and real-time beam diagnostics

Synchrotrons and modern FEL light sources operate with bunch repetition rates in the MHz range. The profile of the electron beam inside the accelerator can be characterized with indirect experimental techniques where linear array detectors are employed to measure the emitted synchrotron radiation or the spectrum of a near-IR laser. To improve the performance of modern beam diagnostics we have developed KALYPSO, a detector system operating with a continuous frame rate of up to 2.7 MHz. To facilitate the integration in different experiments, a modular architecture has been adopted. Different semiconductor micro-strip sensors can be connected to front-end ASICs to optimize the quantum efficiency at different photon energies, ranging from visible light up to near-IR. The front-end electronics are integrated within an heterogeneous DAQ consisting of FPGAs and GPUs, which allows scientists to implement real-time data processing algorithms. The current version of the detector is in operation at the KARA synchrotron light source and at the European XFEL. In this contribution we present the detector architecture, the performance results and the on-going technical developments.

A 400-mA Stable Beam Store with a Superconducting RF System at the PLS-II

At Pohang Light Source (PLS)-II, superconducting RF cavities, which are used energy compensators and make up for the energy loss by emitting synchrotron radiation were developed for the high-brightness photon beam, which has a brightness two orders of magnitude higher than that of predecessor PLS because of a dramatic reduction in higher order modes. The initial beam current for beamline users’ experiments was 150 mA with one cavity, and it increased to 280 mA with two cavities and to 350 mA with three cavities. At beam currents above 320 mA a severe instability was caused by the coupler vacuum, which placed an operation limitation on the high-beam current. Through intensive study, the vacuum instability was avoided, resulting in a stable high beam current in both the decay mode and the top-up mode. The coupling between the forward power and the beam current will change depending on their intensities. When that happens, the positions of maximum induced voltage around the window would also change. The trend is for the position of the maximum induced voltage to approach the window and produce vacuum an instability when forward power is ramped up. When these revelations are considered, one can conclude that the improved relationship between the forward power and the beam current by adjusting the external Q value prevents the maximum induced voltage from occurring around window. Because of the finding of this study, stable operation with a high-beam was realized for as long as over 200 hours or more between faults.

The effect of temperature on cadmium oxide (CdO) nanoparticles produced by synchrotron radiation in the human cancer cells, tissues and tumors

In this work, the effect of temperature of the ablation environment on the properties of Cadmium Oxide (CdO) nanoparticles produced by synchrotron radiation is investigated. To produce nanoparticles, synchrotron radiation pulse with 1064 (nm) wavelength is used to emit Cadmium in the human cancer cells, tissues and tumors. All test parameters were kept constant and human cancer cells, tissues and tumors temperature was changed to produce samples at 20°C and 65°C. Then, ATR–FTIR, XRD, TEM and UV–Visible spectroscopy analyses were performed to investigate their properties. The results show that the size of nanoparticles is increased by increase in temperature of ablation environment. In addition, in the current experimental research, Gold (Au)–Cadmium Oxide (CdO) alloy is created at the size of nano. In this regard, same volume of Gold and Cadmium Oxide (CdO) solutions were mixed together and emitted by the synchrotron radiation pulse with wavelength of 532 (nm). The Gold and Cadmium Oxide (CdO) solutions have been produced, separately, using synchrotron radiation ablation process. To produce them, synchrotron radiation pulse with wavelength of 1064 (nm) and pulse width of 7 (ns) and repeating frequency of 5 (Hz) was used. The results show that synchrotron radiation emission with wavelength of 532 (nm) is an appropriate method for producing Gold compounds in the size of nano. Â

The impact of Faraday effects on polarized black hole images of Sagittarius A*

We study model images and polarization maps of Sagittarius A* at 230 GHz. We post-process GRMHD simulations and perform a fully relativistic radiative transfer calculation of the emitted synchrotron radiation to obtain polarized images for a range of mass accretion rates and electron temperatures. At low accretion rates, the polarization map traces the underlying toroidal magnetic field geometry. At high accretion rates, we find that Faraday rotation internal to the emission region can depolarize and scramble the map. We measure the net linear polarization fraction and find that high accretion rate "jet-disc" models are heavily depolarized and are therefore disfavoured. We show how Event Horizon Telescope measurements of the polarized "correlation length" over the image provide a model-independent upper limit on the strength of these Faraday effects, and constrain plasma properties like the electron temperature and magnetic field strength.

Evidence that particle acceleration in hotspots of FR II galaxies is not constrained by synchrotron cooling

We study the hotspots of powerful radiogalaxies, where electrons accelerated at the jet termination shock emit synchrotron radiation. The turnover of the synchrotron spectrum is typically observed between infrared and optical frequencies, indicating that the maximum energy of non-thermal electrons accelerated at the shock is ≲ TeV for a canonical magnetic field of ∼100 μG. We show that this maximum energy cannot be constrained by synchrotron losses as usually assumed, unless the jet density is unreasonably large and most of the jet upstream energy goes to non-thermal particles. We test this result by considering a sample of hotspots observed at radio, infrared and optical wavelengths.

SOFT: a synthetic synchrotron diagnostic for runaway electrons

Improved understanding of the dynamics of runaway electrons can be obtained by measurement and interpretation of their synchrotron radiation emission. Models for synchrotron radiation emitted by relativistic electrons are well established, but the question of how various geometric effects—such as magnetic field inhomogeneity and camera placement—influence the synchrotron measurements and their interpretation remains open. In this paper we address this issue by simulating synchrotron images and spectra using the new synthetic synchrotron diagnostic tool SOFT (Synchrotron-detecting Orbit Following Toolkit). We identify the key parameters influencing the synchrotron radiation spot and present scans in those parameters. Using a runaway electron distribution function obtained by Fokker–Planck simulations for parameters from an Alcator C-Mod discharge, we demonstrate that the corresponding synchrotron image is well-reproduced by SOFT simulations, and we explain how it can be understood in terms of the parameter scans. Geometric effects are shown to significantly influence the synchrotron spectrum, and we show that inherent inconsistencies in a simple emission model (i.e. not modeling detection) can lead to incorrect interpretation of the images.

Variable millimetre radiation from the colliding-wind binary Cygnus OB2 #8A

In the colliding-wind region of massive binaries, non-thermal radio emission occurs. This non-thermal radio emission (due to synchrotron radiation) has so far been observed at centimetre wavelengths. At millimetre wavelengths, the stellar winds and the colliding-wind region emit more thermal free-free radiation, and it is expected that any non-thermal contribution will be difficult or impossible to detect. We aim to determine if the material in the colliding-wind region contributes substantially to the observed millimetre fluxes of a colliding-wind binary. We also try to distinguish the synchrotron emission from the free-free emission. We monitored the massive binary Cyg OB2 #8A at 3 mm with the NOrthern Extended Millimeter Array (NOEMA) interferometer of the Institut de Radioastronomie Millimetrique (IRAM). The data were collected in 14 separate observing runs (in 2014 and 2016), and provide good coverage of the orbital period. The observed millimetre fluxes range between 1.1 and 2.3 mJy, and show phase-locked variability, clearly indicating that a large part of the emission is due to the colliding-wind region. A simple synchrotron model gives fluxes with the correct order of magnitude, but with a maximum that is phase-shifted with respect to the observations. Qualitatively this phase shift can be explained by our neglect of orbital motion on the shape of the colliding-wind region. A model using only free-free emission results in only a slightly worse explanation of the observations. Additionally, on the map of our observations we also detect the O6.5 III star Cyg OB2 #8B, for which we determine a 3 mm flux of 0.21 +- 0.033 mJy. The question of whether synchrotron radiation or free-free emission dominates the millimetre fluxes of Cyg OB2 #8A remains open. More detailed modelling of this system, based on solving the hydrodynamical equations, is required to give a definite answer.

Multiwavelength analysis of dark matter annihilation and RX-DMFIT

Dark matter (DM) particles are predicted by several well motivated models to yield Standard Model particles through self-annihilation that can potentially be detected by astrophysical observations. In particular, the production of charged particles from DM annihilation in astrophysical systems that contain magnetic fields yields radio emission through synchrotron radiation and X-ray emission through inverse Compton scattering of ambient photons. We introduce RX-DMFIT, a tool used for calculating the expected secondary emission from DM annihilation. RX-DMFIT includes a wide range of customizable astrophysical and particle parameters and incorporates important astrophysics including the diffusion of charged particles, relevant radiative energy losses, and magnetic field modelling. We demonstrate the use and versatility of RX-DMFIT by analyzing the potential radio and X-ray signals for a variety of DM particle models and astrophysical environments including galaxy clusters, dwarf spheroidal galaxies and normal galaxies. We then apply RX-DMFIT to a concrete example using Segue I radio data to place constraints for a range of assumed DM annihilation channels. For WIMP models with Mχ ⩽ 100 GeV and assuming weak diffusion, we find that the leptonic μ+μ− and τ+τ− final states provide the strongest constraints, placing limits on the DM particle cross-section well below the thermal relic cross-section, while even for the bb̄ channel we find limits close to the thermal relic cross-section. Our analysis shows that radio emission provides a highly competitive avenue for dark matter searches.

Thallium-based high-temperature superconductors for beam impedance mitigation in the Future Circular Collider

CERN has recently started a design study for a possible next-generation high-energy hadron–hadron collider (Future Circular Collider—FCC-hh). The FCC-hh study calls for an unprecedented center-of-mass collision energy of 100 TeV, achievable by colliding counter-rotating proton beams with an energy of 50 TeV steered in a 100 km circumference tunnel by superconducting magnets which produce a dipole field of 16 T. The beams emit synchrotron radiation at high power levels, which, to optimize cryogenic efficiency, is absorbed by a beam-facing screen, coated with copper, and held at 50 K in the current design. The surface impedance of this screen has a strong impact on beam stability, and copper at 50 K allows for a limited beam stability margin only. This motivates the exploration of whether high-temperature superconductors (HTS), the only known materials possibly having a surface impedance lower than copper under the required operating conditions, would represent a viable alternative. This paper summarizes the FCC-hh requirements and focuses on identifying the best possible HTS material for this purpose. It reviews in particular the properties of Tl-based HTS, and discusses the consequent motivation for developing a deposition process for such compounds, which should be scalable to the size of the FCC components.

Relativistic plasmas in AGN jets

Relativistic jets of plasma are a key ingredient of many types of Active Galactic Nuclei (AGN). Today we know that AGNs are powered by the accretion of inter stellar material into the gravitational field of a Super Massive Black Hole and that this process can release as much power as a whole galaxy, like the Milky Way, from a region that is comparable to the Solar System in size. Depending on the properties of the central energy source, a large fraction of this power can be involved in the acceleration of magnetized plasmas at relativistic speeds, to form large scale jets. The presence of jets affects the spectrum of AGNs through the emission of synchrotron radiation and Inverse Compton scattering of low energy photons, thus leading to a prominent non-thermal spectrum, some times extending from radio frequencies all the way up to $\gamma$-ray energies. Here we review some characteristic processes of radiation emission in AGN jets, which lead to the emission of photons in the radio, optical, X-ray and $\gamma$-ray bands, and we present the results of a spectroscopic campaign of optical counterparts. We discuss our observations and their connection with $\gamma$-ray properties in a scenario that traces the role of relativistic jets in different classes of AGNs, detected both in the local as well as in the remote Universe.

Parallelized Vlasov-Fokker-Planck solver for desktop personal computers

The numerical solution of the Vlasov-Fokker-Planck equation is a well established method to simulate the dynamics, including the self-interaction with its own wake field, of an electron bunch in a storage ring. In this paper we present Inovesa, a modularly extensible program that uses OpenCL to massively parallelize the computation. It allows a standard desktop PC to work with appropriate accuracy and yield reliable results within minutes. We provide numerical stability-studies over a wide parameter range and compare our numerical findings to known results. Simulation results for the case of coherent synchrotron radiation will be compared to measurements that probe the effects of the micro-bunching instability occurring in the short bunch operation at ANKA. It will be shown that the impedance model based on the shielding effect of two parallel plates can not only describe the instability threshold, but also the presence of multiple regimes that show differences in the emission of coherent synchrotron radiation.

Synchrotron radiation from a curved plasma channel laser wakefield accelerator

A laser pulse guided in a curved plasma channel can excite wakefields that steer electrons along an arched trajectory. As the electrons are accelerated along the curved channel, they emit synchrotron radiation. We present simple analytical models and simulations examining laser pulse guiding, wakefield generation, electron steering, and synchrotron emission in curved plasma channels. For experimentally realizable parameters, a ∼2 GeV electron emits 0.1 photons per cm with an average photon energy of multiple keV.