70 research outputs found
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Energy and angular distributions of radiation power from bending magnet and wiggler sources at a 6-GeV ring
In order to design radiation ports and beam line components, it is essential to understand the distribution of power from a radiation source as a function of both the photon energy and the solid angle of emission. In this preliminary note, we assemble all the formula involved for the case of a bending magnet and a wiggler. Typical distributions are presented for the case of 6-Gev radiation
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Undulator tunability and ring-energy
An Undulator has two properties which make it an extremely attractive source of electromagnetic radiation. The first is that the radiation is concentrated in a number of narrow energy bands known as harmonics of the device. The second characteristic is that under favorable operating conditions, the energy of these harmonics can be shifted or {open_quotes}tuned{close_quotes} over an energy interval which can be as large as two or three times the value of the lowest energy harmonic. Both the photon energy of an undulator as well as its tunability are determined by the period, {lambda}, of the device, the magnetic gap, G (which is larger than the minimum aperture required for injection and operation of the storage ring), and the storage ring energy, E{sub R}. Given the photon energy, E{sub p}, the above parameters ultimately define the limits of operation or tunability of the undulator
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Results of design calculations. Specification of a prototype zone plate for focusing hard x-rays
A zone plate capable of focusing hard x-rays to less than 1 {mu}m spot size is designed and specified. This design is based on the state-of-art fabrication technology available today. This zone plate consists of Cu/Al layers sputtered alternatively on a round stainless steel core. Parameters of this zone plate are given. The focal length f is given for 8Kev x-rays and the thickness is optimized for focusing efficiency of the same x-ray energy
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Nd-Fe-B undulator design for CESR
It is proposed to build a Nd-Fe-B based undulator on CESR ring which would provide pseudomonochromatic tunable radiation in the hard x-ray range from 4 to 15 keV. Such an intense radiation source opens unlimited possibilities for doing exciting science in material science and condensed matter physics. Here, we present the design goals for such an undulator and discuss the influence of various parameters that govern the properties of radiation from undulators. The analysis of these results leads us to select the specific design parameters of the undulator that will meet the radiation needs of the experimental program
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Procurement history of the hybrid undulator for the U-5 Beam Line at the National Synchrotron Light Source
As part of a national multi-institutional Materials Research Group (MRG), Argonne National Laboratory had the responsibility, under a prime contract with the U.S. Department of Energy, of obtaining a Permanent Magnet Hybrid undulator to be used on the U5 Beam Line on the VUV Ring at the National Synchrotron Light Source (NSLS). The procurement involved determining the technical specifications of the device as well as developing an effective procedure for evaluation of the proposals. The conceptual design of the magnetic structure including all pertinent magnetic field properties was developed before the actual procurement process was initiated. In addition, complete calculations of the expected spectral properties of the undulator were performed which included the emittance properties of the VUV ring. The results from both analysis were essential in determining the expected performance of the device and the final choice of operating parameters
Interpretation of Unresolved Mossbauer Spectra in Compounds of I~~~*
Recebido em 2 de Setembro de 1971 The Mossbauer-effect absorption spectra of the rare earth tri-iodides, Lal,, Gdl, and Erl, show evidence of unresolved quadrupole splitting. We propose that the electric field gradient (EFG) responsible for the interaction can be associated with a partially filled p hole (hd in the 5s25p6 eiectronic configuration of I-. The quadrupole coupling parameters and isomer shifts are determined from a least squares fitting of the data using as initial estimates the C[" NQR data for equivalent rare earth tri-chlorides. For Lal, , Gdl, and Erl, these ar
Detection of ice core particles via deep neural networks
Insoluble particles in ice cores record signatures of past climate parameters like vegetation, volcanic activity or aridity. Their analytical detection depends on intensive bench microscopy investigation and requires dedicated sample preparation steps. Both are laborious, require in-depth knowledge and often restrict sampling strategies. To help overcome these limitations, we present a framework based on Flow Imaging Microscopy coupled to a deep neural network for autonomous image classification of ice core particles. We train the network to classify 7 commonly found classes: mineral dust, felsic and basaltic volcanic ash (tephra), three species of pollen (Corylus avellana, Quercus robur, Quercus suber) and contamination particles that may be introduced onto the ice core surface during core handling operations. The trained network achieves 96.8 % classification accuracy at test time. We present the system’s potentials and limitations with respect to the detection of mineral dust, pollen grains and tephra shards, using both controlled materials and real ice core samples. The methodology requires little sample material, is non destructive, fully reproducible and does not require any sample preparation step. The presented framework can bolster research in the field, by cutting down processing time, supporting human-operated microscopy and further unlocking the paleoclimate potential of ice core records by providing the opportunity to identify an array of ice core particles. Suggestions for an improved system to be deployed within a continuous flow analysis workflow are also presented
THE ITALIAN QUATERNARY VOLCANISM
The peninsular and insular Italy are punctuated by Quaternary volcanoes and their rocks constitute an important aliquot of the Italian Quaternary sedimentary successions. Also away from volcanoes themselves, volcanic ash layers are a common and frequent feature of the Quaternary records, which provide us with potential relevant stratigraphic and chronological markers at service of a wide array of the Quaternary science issues. In this paper, a broad representation of the Italian volcano-logical community has joined to provide an updated comprehensive state of art of the Italian Quaternary volcanism. The eruptive history, style and dynamics and, in some cases, the hazard assessment of about thirty Quaternary volcanoes, from the north-ernmost Mt. Amiata, in Tuscany, to the southernmost Pantelleria and Linosa, in Sicily Channel, are here reviewed in the light of the substantial improving of the methodological approaches and the overall knowledge achieved in the last decades in the vol-canological field study. We hope that the present review can represent a useful and agile document summarising the knowledege on the Italian volcanism at the service of the Quaternary community operating in central Mediterranean area
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