Synchrotron light: a physics journey from laboratory to cosmos

Synchrotron Radiation Applications in the Siberian Synchrotron and Terahertz Radiation Center

The thermal plasma of galaxy clusters lost most of its information on how structure formation proceeded as a result of dissipative processes. In contrast, non-equilibrium distributions of cosmic rays (CRs) preserve the information about their injection and transport processes and provide thus a unique window of current and past structure formation processes. This information can be unveiled by observations of non-thermal radiative processes, including radio synchrotron, hard X-ray and γ-ray emission. To explore this, we use high-resolution simulations of a sample of galaxy clusters spanning a mass range of about two orders of magnitudes, and follow self-consistent CR physics on top of the radiative hydrodynamics. We model relativistic electrons that are accelerated at cosmological structure formation shocks and those that are produced in hadronic interactions of CRs with ambient gas protons. We find that the CR proton pressure traces the time integrated non-equilibrium activities of clusters and is modulated by the recent dynamical activities. In contrast, the pressure of primary shock-accelerated CR electrons resembles current accretion and merging shock waves that break at the shallow cluster potential in the virial regions. The resulting synchrotron emission is predicted to be polarized and has an inhomogeneous and aspherical spatial distribution which matches the properties of observed radio relics. We propose a unified scheme for the generation of giant radio haloes as well as radio minihaloes that naturally arises from our simulated synchrotron surface brightness maps and emission profiles. Giant radio haloes are dominated in the centre by secondary synchrotron emission with a transition to the radio synchrotron radiation emitted from primary, shock-accelerated electrons in the cluster periphery. This model is able to explain the regular structure of radio haloes by the dominant contribution of hadronically produced electrons. At the same time, it is able to account for the observed correlation of mergers with radio haloes, the larger peripheral variation of the spectral index, and the large scatter in the scaling relation between cluster mass and synchrotron emission. Future low-frequency radio telescopes (LOFAR, GMRT, MWA, LWA) are expected to probe the accretion shock regions of clusters and the warm–hot intergalactic medium, depending on the adopted model for the magnetic fields. The hadronic origin of radio haloes can be scrutinized by the detection of pion-decay-induced γ-rays following hadronic CR interactions. The high-energy γ-ray emission depends only weakly on whether radiative or non-radiative gas physics is simulated due to the self-regulated nature of the CR cooling processes. Our models predict a γ-ray emission level that should be observable with the GLAST satellite.

A technique has been developed for determining mercury content in the concentration range of 1–1000 μg/g in hair samples by X‐ray fluorescence analysis using synchrotron radiation (synchrotron radiation X‐ray fluorescence, Siberian Synchrotron and Terahertz Radiation Center, Budker Institute of Nuclear Physics SB RAS). The mercury content was identified in archeological hair samples from an ancient burial of Xiongnu nobility (Mongolia, mound 22, 1st century BC–1st century AD); the content values were elevated (up to 1100 μg/g) in all the samples (n = 41). An X‐ray microanalysis using polycapillary lenses in a confocal scheme (confocal X‐ray microscopy station) was developed at the Synchrotron radiation X‐ray fluorescence to establish mercury distribution in a cross section of hair shaft with a spatial resolution of 5 μm. The findings of the study make it possible to assume exogenous income of mercury (from the burial environment) to the hair.

The production of both gravitational waves and short gamma-ray bursts (sGRBs) is widely associated with the merger of compact objects. Several studies have modelled the evolution of the electromagnetic emission using the synchrotron emission produced by the deceleration of both a relativistic top-hat jet seen off-axis, and a wide-angle quasi-spherical outflow (both using numerical studies). In this study we present an analytical model of the synchrotron and synchrotron self-Compton (SSC) emission for an off-axis top-hat jet and a quasi-spherical outflow. We calculate the light curves obtained from an analytic model in which the synchrotron and SSC emission (in the fast- or slow-cooling regime) of an off-axis top-hat jet and a quasi-spherical outflow are decelerated in either a homogeneous or a wind-like circumburst medium. We show that the synchrotron emission of the quasi-spherical outflow is stronger than that of the off-axis jet during the first $\sim$ 10 - 20 days, and weaker during the next $\gtrsim$ 80 days. Moreover, we show that if the off-axis jet is decelerated in a wind-like medium, then the SSC emission is very likely to be detected. Applying a MCMC code to our model (for synchrotron emission only), we find the best-fit values for the radio, optical and X-ray emission of GRB 170817A which are in accordance with observations. For GRB 170817A, we find using our model that the synchrotron emission generated by the quasi-spherical outflow and off-axis top-hat jet increase as $F_\nu\propto t^{\alpha}$ with $\alpha\lesssim 0.8$ and $\alpha>3$, respectively. Finally, we obtain the correspondent SSC light curves which are in accordance with the very-high-energy gamma-ray upper limits derived with the GeV - TeV observatories.

Synchrotron radiation is generated whenever electrically charged particles moving at speeds near that of light are forced into bent paths by magnetic fields. It is electromagnetic radiation, which can be visible light, ultraviolet or X-rays, depending on the energy of the particles and the strength of the magnetic field. The radiation is named for the class of accelerators in which it first became a serious problem, electron synchrotrons. Because electrons have less than 1/1800th as much mass as protons, they reach relativistic velocities at much lower energies than do protons. At high energies synchrotron radiation robs so much energy from electrons moving in circular paths that when what is now the world's most energetic electron accelerator the 20-billion-electron-volt machine of the Stanford Linear Accelerator Center -was planned, the builders decided to make it a straight line two miles long. It may be considered somewhat ironic that that linear accelerator now supplies accelerated electrons to a facility that uses synchrotron radiation for research in several different scientific fields. Synchrotron radiation used to be considered a dead loss by accelerator operators. In recent years it has suddenly become a very important new research field. In the words of Herman Winick, deputy director of the Stanford Synchrotron Radiation Laboratory, There is an explosive growth of interest in its applications. At the moment there are about 10 storage rings and 11 synchrotrons around the world at which synchrotron radiation experiments are done. The SSRL gets its synchrotron radiation from the SPEAR storage ring. A smaller storage ring at the University of Wisconsin, the Deutsches Elektronen-Synchrotron at Hamburg, and more than one ring at Novosibirsk in the USSR are among those in the world now supplying synchrotron radiation for experiments. The attitude of the U.S. scientific establishment and its government funders has undergone a total turnaround from three or four years ago, Winick says. At that time Winick was working at the now defunct Cambridge Electron Accelerator in Cambridge, Mass. An attempt to get $1 million a year to keep the CEA going as a facility for synchrotron radiation was unsuccessful. Over the next three years, the National Science Foundation plans to give about $7 million to the SSRL alone. At the same time, plans have been announced for enlargement of the facility in Wisconsin and for another national synchrotron radiation facility at Brookhaven National Laboratory, where an accelerator will be built to be solely a source of synchrotron radiation. Other sources of X-rays, of which the best are 60-kilovolt rotating anode tubes, do not provide the broad spectrum or high power of synchrotron radiation. As an example of the difference, Winick cites a group of scientists from the Bell Telephone Laboratories who came to SSRL to do a spectrum that they had previously done by other methods. With synchrotron radiation it took them 20 minutes to do a spectrum that had previously taken two weeks. Another advantage of synchrotron radiation is that it comes in bursts that correspond to the bunches of electrons circulating in the storage ring. This gives experiments a built-in time resolution and makes possible the study of chemical and biological processes over time. A study of contracting muscle fibers is one possible experiment. Other biological possibilities include studies of membrane action, which are a particular interest of Sebastian Doniach, who has just completed his The two-mile linear accelerator feeds electrons to the SPEAR storage ring (lower right of top picture), where they generate synchrotron radiation used by the SSRL (building at right of ring). Mirrors permit several experiments to share one radiation beam (bottom).

Microfabrication of high-aspect-ratio or three-dimensional (3-D) structures is critical for the production of various components for micro electro mechanical systems (MEMS). The term “three-dimensional structure” refers to a structure with a free-form surface or sloped sidewall. This article describes the fabrication of 3-D microstructures using synchrotron radiation (SR) lithography. SR lithography technology is one component of the LIGA process, and it is also called X-ray lithography. MEMS devices have attracted a great deal of attention, and further studies are needed to realize their full potential. Among fabrication technologies, microfabrication, developed using a semiconductor process, is in high demand. Recently, the demand for MEMS devices has diversified, and microfabrication technologies for the production of high-aspect-ratio and 3-D structures are required to meet this demand. Microfabrication technologies for the production of high-aspect-ratio structures include deep reactive-ion etching (D-RIE) and deep X-ray lithography in the LIGA process utilizing SR light. In the former, because SR light is highly directional, it is possible to fabricate a structure with a thickness of several hundred to one thousand micrometers. Moreover, because SR light contains X-ray (short wavelength) regions, it is possible to transfer patterns that are ≤ 1 m (diffraction during exposure does not occur readily). Therefore, SR lithography has been used as a fabrication technology for high-aspect-ratio structures. It is possible to fabricate high-aspect-ratio structures using D-RIE. However, because a patterned, indented sidewall called a scallop is formed due to the nature of the process mechanism, it is difficult to fabricate structures with smooth sidewall surfaces. On the other hand, it is possible to fabricate structures with smooth sidewall surfaces using SR lithography, which is discussed in more detail in Chapter 2. In the field of 3-D microfabrication, techniques such as KOH anisotropic etching of silicon and laser machining have been employed (Tsukada et al., 2005). However, 3-D fabrication using SR lithography was recently achieved, and results have already been reported (Horade & Sugiyama, 2009; Lee & Lee, 2003; Matsuzuka et al., 2005; Mekaru et al., 2007; Sugiyama et al., 2004; Tabata et al., 2000). Nanoscale 3-D microfabrication technology using SR lithography can be used to fabricate high-aspect-ratio structures by exploiting the properties of SR, and free-form structures with inclined sidewall surfaces can be fabricated. Additionally, this article describes 3-D polytetrafluoroethylene (PTFE) microstructures fabricated by SR ablation. Because PTFE is a remarkable material, there are high

The X-ray fluorescence (XRF) analysis with using synchrotron radiation (SR) is a powerful technique for resolving elemental composition of the different samples with high sensitivity. This technique is suitable for nondestructive multi-elemental analyses of heavy elements such as rare-earth elements. In this paper, the choice of optimal excitation energies for the determination of the trace amounts of the different rare-earth elements (REEs) from La to Lu by the SRXRF method was discussed. The SRXRF spectra have received at the synchrotron radiation (SR) station using radiation from the 9-pole wiggler on VEPP-4M at the Siberian Synchrotron and Terahertz Radiation Center (SSTRC). As samples the Russian and international standards of magmatic rocks (AGV-1, BCR-1, DNC-1, BIR-1, SGD-1A, and G-2) were used. This powerful technique should be useful for nondestructive analyses of rare-earth and heavy elements in geological, geochemical and archaeological samples as well as industrial materials.

The direct analysis of the biological tissue samples is a great advantage of the X-ray Fluorescent Technique with Synchrotron Radiation (SRXRF). SRXRF method is realized on the basis of INP SB RAS in Siberian Synchrotron and Terahertz Radiation Centre. In the present work, the whole liver tissue samples were dried under weight and analyzed in the form of parallel-plane fragments. The minimization of sample preparation procedures is known to significantly reduce the risks of the sample contamination and loss of analyte. The preparation procedure, which was used in the present work, was carried out without lyophilization, grinding and pelletizing of liver tissue samples. Elemental concentrations in the samples were calculated using the calibration and constructed on the basis of biological certified reference materials. It was found that there weren’t any significant differences between elemental concentrations in the case of the direct analysis of parallel-plane liver fragments and concentrations obtained for the same liver samples after grinding and pelletizing. Two unbroken samples and one grinded sample were measured 5 times to assess the reproducibility. The relative standard deviation for each sample was calculated, and it included both the assessment of the reproducibility and the heterogeneity of the elemental distribution in the sample. The validation of the results obtained by SRXRF method was estimated by the comparison with the results obtained by another method, namely by Two-Jet Plasma Atomic Emission Spectrometry (TJP-AES). Thereby the offered way of sample preparation procedure using external standard method for calculation of elemental concentrations can be applied for SRXRF analysis of biological samples. Keywords : x-ray fluorescent analysis, synchrotron radiation, sample preparation, biological tissue, liver (Russian) DOI: http://dx.doi.org/10.15826/analitika.2015.19.2.008 V.A. Trunova 1,2 , A.V. Sidorina 1 , V.V. Zvereva 1 1 A.V. Nikolaev Institute of Inorganic С hemistry SB RAS, Novosibirsk, Russian Federation 2 Novosibirsk State University , Novosibirsk, Russian Federation

Photoionization and Collisional Ionization of Excited Atoms using Synchrotron and Laser Radiations

We describe the development of activity at the Siberian Center for Synchrotron and Terahertz Radiation at Budker Institute of Nuclear Physics (BINP), SB RAS, since 1974, when the history of experiments with synchrotron radiation (SR) in the world was just beginning–there were no dedicated sources of radiation and works can be carried out at several nuclear centers in the world. BINP made a significant contribution to the development of synchrotron radiation sources, and SB RAS institutes did their part for development of SR application to problems of chemistry, catalysis, biology, geology and materials science. The experiments were made at VEPP-3/VEPP-4 installation.

This issue brings together papers from the 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) held in Japan in August 1997. This is one of the major synchrotron radiation conferences, held every three years, and has so far published its proceedings in a variety of journals. Now that the synchrotron radiation community have a journal of their own it is only natural that the proceedings of this largest synchrotron radiation conference are published in JSR. It is particularly satisfying that this has coincided with the 50th anniversary of the ®rst observation of synchrotron radiation light from the General Electric 70 MeV synchrotron. The SRI conferences have evolved over the years with the more recent conferences covering not only research and development of synchrotron radiation instrumentation but also the exploitation of synchrotron radiation for diffraction, spectroscopic and imaging applications in the physical, chemical, biological and medical sciences. This issue thus brings together articles from the whole spectrum of synchrotron radiation activities and re ects the interdisciplinary nature of this rapidly expanding community. The conference coincided with the opening of one of the world's most powerful synchrotron radiation sources, the 8 GeV SPring-8 storage ring at the Harima Science Garden City, Japan. The energy and size of the SPring-8 source are several orders of magnitude higher than those of the GEC synchrotron 50 years ago. The extent of the synchrotron radiation community has increased beyond the expectations of the pioneers of synchrotron radiation science, several of whom were present at the conference and whose contributions form part of this issue. We are particularly pleased that the conference delegates were able to hear a ®rst-hand account from Dr John Blewett, who had predicted and observed the shrinkage of the electron orbit due to synchrotron radiation in 1945 (see this issue, pages 135±139). This issue thus represents an important stage in the development and exploitation of synchrotron radiation as well as a signi®cant step for JSR. The papers for this proceedings issue were refereed to the usual standards of JSR and the review process differed in signi®cant ways from previous SRI proceedings. Previously, the majority of the papers had been refereed during the meeting. The papers for this conference were handled by JSR Co-editors and three Guest Editors (Professors Ohno, Miyahara and Ueki), who selected the referees and followed the normal refereeing procedure whereby referees were given up to six weeks to carry out rigorous refereeing. As a result, substantial revision to the original manuscripts took place in a large number of cases. Despite much effort from the Co-editors and Guest Editors, a signi®cant number of papers did not become acceptable. We believe that this effort is re ected in the improved quality of the proceedings and would like to invite comment from the community for future proceedings. Recently, JSR entered into the citation ranking tables for the ®rst time; on impact factor JSR is third out of 37 journals covering instruments and instrumentation, eighth out of 46 covering optics and 18th out of 60 covering applied physics. We acknowledge here then the excellent papers submitted by authors, and the referees who have served the journal so well. We believe that this issue, which represents the single biggest undertaking by JSR, will go further towards improving the impact of our community's single dedicated journal. We are grateful to the Managing Editor and his team for their tremendous effort in ensuring the high quality of production; their professionalism is evident throughout the issue. We thank Dr H. Ohno, chairman of the publication committee, for acting as a Special Editor for this issue and coordinating the publication activities at the conference. This issue is a testimony to our stated objective of `providing the focus for the whole of the synchrotron radiation community'. On the 50th anniversary of synchrotron radiation, the range of opportunities available today is extremely broad with the synchrotron radiation spectrum providing unique experimental capabilities from infrared (meV) to hard X-rays (>300 keV). Several synchrotron radiation centres have catered for this range of activities by building two synchrotron radiation sources; NSLS is a prime example of the 1980's, where the X-ray source was complemented by a low-energy source, and, more recently, at Harima, SPring-8 is complemented by the 1.5 GeV SUBARU ring. The issue also contains our ®rst Book Review; this will become a regular feature and we invite you to submit

The SKIF Synchrotron and Terahertz Radiation Center provides users from various organizations with access to modern analytical techniques using synchrotron radiation beams for a wide range of research work. The general direction in developing the Center is now focused on generating new approaches to using synchrotron radiation.

HERMES is a new proposed experiment at DESY to measure the spin dependent structure functions of proton and neutron in the HERA electron ring [1]. High statistical precision is obtained by using a storage cell that increases the density of the internal polarized gas target to a value of 1014 atoms/cm2. Synchrotron radiation has two effects that may harm this experiment: The storage cell is irradiated by synchrotron photons and radiation scattered from the target gas and from the cell walls enters the front chambers of the detector. In this report the amount of synchrotron radiation is calculated and means are proposed to protect an experiment like the HERMES experiment from synchroton radiation. An efficient collimator system is necessary for the operation of the experiment. Narrow collimators have secondary effects on the beam. One aspect is the additional background production at the edges of the collimators. The Monte-Carlo program SYNTRACK [2] was written which allows a detailed simulation of synchrotron radiation, of scattered radiation, of beam tail generation by rest-gas bremsstrahlung and of the scraping of the beam tails by the collimators.

We present results of a 3D model of optical to gamma-ray emission from the slot gap accelerator of a rotation-powered pulsar. Primary electrons accelerating to high-altitudes in the unscreened electric field of the slot gap reach radiation-reaction limited Lorentz factors of 2 x 10^7, while electron-positron pairs from lower-altitude cascades flow along field lines interior to the slot gap. The curvature, synchrotron and inverse Compton radiation of both primary electrons and pairs produce a broad spectrum of emission from infra-red to GeV energies. Both primaries and pairs undergo cyclotron resonant absorption of radio photons, allowing them to maintain significant pitch angles. Synchrotron radiation from pairs with a power-law energy spectrum with Lorentz factors 10^2 - 10^5, dominate the spectrum up to 10 MeV. Synchrotron and curvature radiation of primaries dominates from 10 MeV up to a few GeV. We examine the energy-dependent pulse profiles and phase-resolved spectra for parameters of the Crab pulsar as a function of magnetic inclination and viewing angle, comparing to broad-band data. In most cases, the pulse profiles are dominated by caustics on trailing field lines. We also explore the relation of the high-energy and the radio profiles, as well as the possibility of caustic formation in the radio cone emission. We find that the Crab pulsar profiles and spectrum can be reasonably well reproduced by a model with viewing angle 45 degrees and inclination angle 100 or 80 degrees. This model predicts that the slot gap emission below 200 MeV will exhibit correlations in time and phase with the radio emission.

We have acquired radio continuum data between 70\,MHz and 48\,GHz for a sample of 19 southern starburst galaxies at moderate redshifts ($0.067 < z < 0.227$) with the aim of separating synchrotron and free-free emission components. Using a Bayesian framework we find the radio continuum is rarely characterised well by a single power law, instead often exhibiting low frequency turnovers below 500\,MHz, steepening at mid-to-high frequencies, and a flattening at high frequencies where free-free emission begins to dominate over the synchrotron emission. These higher order curvature components may be attributed to free-free absorption across multiple regions of star formation with varying optical depths. The decomposed synchrotron and free-free emission components in our sample of galaxies form strong correlations with the total-infrared bolometric luminosities. Finally, we find that without accounting for free-free absorption with turnovers between 90 to 500\,MHz the radio-continuum at low frequency ($\nu < 200$\,MHz) could be overestimated by upwards of a factor of twelve if a simple power law extrapolation is used from higher frequencies. The mean synchrotron spectral index of our sample is constrained to be $\alpha=-1.06$, which is steeper then the canonical value of $-0.8$ for normal galaxies. We suggest this may be caused by an intrinsically steeper cosmic ray distribution.