Laser-slicing at a low-emittance storage ring

2019 ◽  
Vol 26 (5) ◽  
pp. 1523-1538
Author(s):  
Simone Di Mitri ◽  
William Barletta ◽  
Anna Bianco ◽  
Ivan Cudin ◽  
Bruno Diviacco ◽  
...  
Keyword(s):  
Storage Ring ◽  
Laser Power ◽  
State Of The Art ◽  
Beam Emittance ◽  
X Ray ◽  
Average Laser Power ◽  
Spectral Separation ◽  
Order Of Magnitude ◽  
Transverse Gradient ◽  
Low Emittance

Laser-slicing at a diffraction-limited storage ring light source in the soft X-ray region is investigated with theoretical and numerical modelling. It turns out that the slicing efficiency is favoured by the ultra-low beam emittance, and that slicing can be implemented without interference to the standard multi-bunch operation. Spatial and spectral separation of the sub-picosecond radiation pulse from a hundreds of picosecond-long background is achieved by virtue of 1:1 imaging of the radiation source. The spectral separation is enhanced when the radiator is a transverse gradient undulator. The proposed configuration applied to the Elettra 2.0 six-bend achromatic lattice envisages total slicing efficiency as high as 10−7, one order of magnitude larger than the demonstrated state-of-the-art, at the expense of pulse durations as long as 0.4 ps FWHM and average laser power as high as ∼40 W.

Accelerator-based X-ray sources: synchrotron radiation, X-ray free electron lasers and beyond

2019 ◽  
Vol 377 (2147) ◽  
pp. 20180231 ◽  
Author(s):  
Tetsuya Ishikawa
Keyword(s):  
Synchrotron Radiation ◽  
Storage Ring ◽  
Free Electron ◽  
Continuous Wave ◽  
Transitional Period ◽  
Light Sources ◽  
X Rays ◽  
Free Electron Lasers ◽  
Beam Emittance ◽  
X Ray

The evolution of synchrotron radiation (SR) sources and related sciences is discussed to explain the ‘generation’ of the SR sources. Most of the contemporary SR sources belong to the third generation, where the storage rings are optimized for the use of undulator radiation. The undulator development allowed to reduction of the electron energy of the storage ring necessary for delivering 10 keV X-rays from the initial 6–8 GeV to the current 3 Gev. Now is the transitional period from the double-bend-achromat lattice-based storage ring to the multi-bend-achromat lattice to achieve much smaller electron beam emittance. Free electron lasers are the other important accelerator-based light sources which recently reached hard X-ray regime by using self-amplified spontaneous emission scheme. Future accelerator-based X-ray sources should be continuous wave X-ray free electron lasers and pulsed X-ray free electron lasers. Some pathways to reach the future case are discussed. This article is part of the theme issue ‘Fifty years of synchrotron science: achievements and opportunities’.

scholarly journals X-ray signatures of black hole feedback: hot galactic atmospheres in IllustrisTNG and X-ray observations

2020 ◽  
Vol 494 (1) ◽  
pp. 549-570 ◽  
Author(s):  
Nhut Truong ◽  
Annalisa Pillepich ◽  
Norbert Werner ◽  
Dylan Nelson ◽  
Kiran Lakhchaura ◽  
...  
Keyword(s):  
State Of The Art ◽  
Quenching Mechanism ◽  
Lower Mass ◽  
Cosmological Simulations ◽  
X Ray ◽  
Star Forming ◽  
Magnitude Range ◽  
Order Of Magnitude ◽  
Quenching Mechanisms ◽  
Gaseous Atmospheres

ABSTRACT Hot gaseous atmospheres that permeate galaxies and extend far beyond their stellar distribution, where they are commonly referred to as the circumgalactic medium, imprint important information about feedback processes powered by the stellar populations of galaxies and their central supermassive black holes (SMBHs). In this work, we study the properties of this hot X-ray emitting medium using the IllustrisTNG cosmological simulations. We analyse their mock X-ray spectra, obtained from the diffuse and metal-enriched gas in TNG100 and TNG50, and compare the results with X-ray observations of nearby early-type galaxies. The simulations reproduce the observed X-ray luminosities (LX) and temperature (TX) at small (<Re) and intermediate (<5Re) radii reasonably well. We find that the X-ray properties of lower mass galaxies depend on their star formation rates. In particular, in the magnitude range where the star-forming and quenched populations overlap, $M_{\rm K}\sim -24\ (M_*\sim 10^{10.7}\, \mathrm{M}_\odot)$, we find that the X-ray luminosities of star-forming galaxies are on average about an order of magnitude higher than those of their quenched counterparts. We show that this diversity in LX is a direct manifestation of the quenching mechanism in the simulations, where the galaxies are quenched due to gas expulsion driven by SMBH kinetic feedback. The observed dichotomy in LX is thus an important observable prediction for the SMBH feedback-based quenching mechanisms implemented in state-of-the-art cosmological simulations. While the current X-ray observations of star-forming galaxies are broadly consistent with the predictions of the simulations, the observed samples are small and more decisive tests are expected from the sensitive all-sky X-ray survey with eROSITA.

scholarly journals Pixel detectors for diffraction-limited storage rings

2014 ◽  
Vol 21 (5) ◽  
pp. 1006-1010 ◽  
Author(s):  
Peter Denes ◽  
Bernd Schmitt
Keyword(s):  
Synchrotron Radiation ◽  
Storage Ring ◽  
Dynamic Range ◽  
State Of The Art ◽  
Storage Rings ◽  
X Rays ◽  
X Ray ◽  
Current State ◽  
Pixel Detectors ◽  
Radiation Sources

Dramatic advances in synchrotron radiation sources produce ever-brighter beams of X-rays, but those advances can only be used if there is a corresponding improvement in X-ray detectors. With the advent of storage ring sources capable of being diffraction-limited (down to a certain wavelength), advances in detector speed, dynamic range and functionality is required. While many of these improvements in detector capabilities are being pursued now, the orders-of-magnitude increases in brightness of diffraction-limited storage ring sources will require challenging non-incremental advances in detectors. This article summarizes the current state of the art, developments underway worldwide, and challenges that diffraction-limited storage ring sources present for detectors.

Status of a beamline for a 60‐period soft x‐ray undulator in the low emittance operation of the Photon Factory storage ring

1989 ◽  
Vol 60 (7) ◽  
pp. 1889-1892 ◽  
Author(s):  
Hideki Maezawa ◽  
Akio Toyoshima ◽  
Yasushi Kagoshima ◽  
Kouichi Mori ◽  
Tetsuya Ishikawa
Keyword(s):  
Storage Ring ◽  
X Ray ◽  
Photon Factory ◽  
Low Emittance

scholarly journals Hard X-ray nanofocusing at low-emittance synchrotron radiation sources

2014 ◽  
Vol 21 (5) ◽  
pp. 996-1005 ◽  
Author(s):  
Christian G. Schroer ◽  
Gerald Falkenberg
Keyword(s):  
Electron Beam ◽  
Synchrotron Radiation ◽  
Storage Ring ◽  
Source Parameters ◽  
Gaussian Model ◽  
Scanning Microscopy ◽  
X Ray ◽  
Radiation Sources ◽  
Central Cone ◽  
Low Emittance

X-ray scanning microscopy relies on intensive nanobeams generated by imaging a highly brilliant synchrotron radiation source onto the sample with a nanofocusing X-ray optic. Here, using a Gaussian model for the central cone of an undulator source, the nanobeam generated by refractive X-ray lenses is modeled in terms of size, flux and coherence. The beam properties are expressed in terms of the emittances of the storage ring and the lateral sizes of the electron beam. Optimal source parameters are calculated to obtain efficient and diffraction-limited nanofocusing. With decreasing emittance, the usable fraction of the beam for diffraction-limited nanofocusing experiments can be increased by more than two orders of magnitude compared with modern storage ring sources. For a diffraction-limited storage ring, nearly the whole beam can be focused, making these sources highly attractive for X-ray scanning microscopy.

Stability of NSLS-II girder–magnet assembly

2010 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
V. Ravindranath ◽  
S. Sharma ◽  
L. Doom ◽  
C. Channing ◽  
F. Lincoln ◽  
...  
Keyword(s):  
Storage Ring ◽  
High Stability ◽  
State Of The Art ◽  
Temperature Fluctuations ◽  
Ambient Vibration ◽  
Third Generation ◽  
Medium Energy ◽  
Design Features ◽  
The Stability ◽  
Low Emittance

The low-emittance design of the NSLS-II (a new state-of-the-art medium energy third-generation storage ring) requires that the uncorrelated vertical RMS motion between the multipole magnets on a girder be less than 25 nm. The stability of the girder–magnet assembly is affected by factors such as ambient vibration, temperature fluctuations and diurnal floor motion in the storage ring. In this paper we discuss the design features of a high-stability girder–magnet assembly for the NSLS-II.

scholarly journals Coherence properties of the high-energy fourth-generation X-ray synchrotron sources

2019 ◽  
Vol 26 (6) ◽  
pp. 1851-1862 ◽  
Author(s):  
R. Khubbutdinov ◽  
A. P. Menushenkov ◽  
I. A. Vartanyants
Keyword(s):  
Electron Beam ◽  
Storage Ring ◽  
High Energy ◽  
Storage Rings ◽  
Relative Energy ◽  
Diffraction Limit ◽  
Energy Spread ◽  
Fourth Generation ◽  
X Ray ◽  
Low Emittance

An analysis of the coherence properties of the fourth-generation high-energy storage rings with emittance values of 10 pm rad is performed. It is presently expected that a storage ring with these low emittance values will reach diffraction limit at hard X-rays. Simulations of coherence properties were performed with the XRT software and an analytical approach for different photon energies from 500 eV to 50 keV. It was demonstrated that a minimum photon emittance (diffraction limit) reached at such storage rings is λ/2π. Using mode decomposition it is shown that, for the parameters of the storage ring considered in this work, the diffraction limit will be reached for soft X-ray energies of 500 eV. About ten modes will contribute to the radiation field at 12 keV photon energy and even more modes give a contribution at higher photon energies. Energy spread effects of the electron beam in a low-emittance storage ring were analysed in detail. Simulations were performed at different relative energy spread values from zero to 2 × 10−3. A decrease of the degree of coherence with an increase of the relative energy spread value was observed. This analysis shows that, to reach the diffraction limit for high photon energies, electron beam emittance should go down to 1 pm rad and below.

Development of a method for multielemental determination in water by EDXRF with radioisotopic source of 238Pu.

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Camilo Fuentes Serrano ◽  
Juan Reinaldo Estevez Alvares ◽  
Alfredo Montero Alvarez ◽  
Ivan Pupo Gonzales ◽  
Zahily Herrero Fernandez ◽  
...  
Keyword(s):  
Thin Layer ◽  
Expanded Uncertainty ◽  
Considerable Decrease ◽  
X Ray ◽  
Precipitation Efficiency ◽  
Method Of Determination ◽  
Sensitivity Curves ◽  
Order Of Magnitude ◽  
Metrological Parameters

A method for determination of Cr, Fe, Co, Ni, Cu, Zn, Hg and Pb in waters by Energy Dispersive X Ray Fluorescence (EDXRF) was implemented, using a radioisotopic source of 238Pu. For previous concentration was employed a procedure including a coprecipitation step with ammonium pyrrolidinedithiocarbamate (APDC) as quelant agent, the separation of the phases by filtration, the measurement of filter by EDXRF and quantification by a thin layer absolute method. Sensitivity curves for K and L lines were obtained respectively. The sensitivity for most elements was greater by an order of magnitude in the case of measurement with a source of 238Pu instead of 109Cd, which means a considerable decrease in measurement times. The influence of the concentration in the precipitation efficiency was evaluated for each element. In all cases the recoveries are close to 100%, for this reason it can be affirmed that the method of determination of the studied elements is quantitative. Metrological parameters of the method such as trueness, precision, detection limit and uncertainty were calculated. A procedure to calculate the uncertainty of the method was elaborated; the most significant source of uncertainty for the thin layer EDXRF method is associated with the determination of instrumental sensitivities. The error associated with the determination, expressed as expanded uncertainty (in %), varied from 15.4% for low element concentrations (2.5-5 μg/L) to 5.4% for the higher concentration range (20-25 μg/L).

TEM Studies and Contact Resistance of Au/Ni/Ti/Ta/n-GaN Ohmic Contacts

2003 ◽  
Vol 764 ◽  
Author(s):  
D.N. Zakharov ◽  
Z. Liliental-Weber ◽  
A. Motayed ◽  
S.N. Mohammad
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
High Resolution Electron Microscopy ◽  
X Ray ◽  
Electron Energy Loss Spectrometry ◽  
Resolution Electron ◽  
Order Of Magnitude ◽  
Contact Surfaces ◽  
Electron Energy Loss ◽  
Magnitude Difference

AbstractOhmic Ta/Ti/Ni/Au contacts to n-GaN have been studied using high resolution electron microscopy (HREM), energy dispersive X-ray spectrometry (EDX) and electron energy loss spectrometry (EELS). Two different samples were used: A - annealed at 7500C withcontact resistance 5×10-6 Ω cm2 and B-annealed at 7750C with contact resistance 6×10-5 Ω cm2. Both samples revealed extensive in- and out-diffusion between deposited layers with some consumption ofGaNlayerand formation of TixTa1-xN50 (0<x<25) at the GaN interface. Almost an order of magnitude difference in contact resistances can be attributed to structure and chemical bonding of Ti-O layers formed on the contact surfaces.

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