Search results for "Undulator"
showing 10 items of 16 documents
Low-temperature luminescence of ScF3 single crystals under excitation by VUV synchrotron radiation
2020
The work was supported by the Latvian Science Council grant LZP-2018/2-0358. The research leading to this result has also been supported by the project CALIPSO plus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. The author is grateful to K. Chernenko (MAX IV Laboratory, Lund University) for his assistance during beamtime experiments and to A. I. Popov for the fruitful discussions. V.P. also acknowledges Valsts pētījumu programma “Augstas enerģijas fizika un paātrinātāju tehnoloģijas” (Projekta Nr. VPP-IZM-CERN-2020/1-0002). REFERENCES
Radiation emission at channeling of electrons in a strained layer undulator crystal
2013
Abstract Experiments have been performed at the Mainz Microtron MAMI to explore the radiation emission spectra from a crystalline undulator at electron beam energies of 270 and 855 MeV. The epitaxially grown graded composition strained layer Si 1 - x Ge x undulator had 4-period with a period length λ u = 9.9 μ m . Spectra taken at the beam energy of 270 MeV at channeling in the undulating (110) planes exhibit a broad excess yield around the theoretically expected photon energies of 0.069 MeV, as compared with a flat silicon reference crystal. Model calculations on the basis of synchrotron-like radiation emission from finite single arc elements, taking into account also coherence effects, su…
Radiation from multi-GeV electrons and positrons in periodically bent silicon crystal
2014
A periodically bent Si crystal is shown to efficiently serve for producing highly monochromatic radiation in a gamma-ray energy spectral range. A short-period small-amplitude bending yields narrow undulator-type spectral peaks in radiation from multi-GeV electrons and positrons channeling through the crystal. Benchmark theoretical results on the undulator are obtained by simulations of the channeling with a full atomistic approach to the projectile-crystal interactions over the macroscopic propagation distances. The simulations are facilitated by employing the MBN Explorer package for molecular dynamics calculations on the meso-, bio- and nano-scales. The radiation from the ultra-relativist…
Observation of optical Smith-Purcell radiation at an electron beam energy of 855 MeV.
2002
Smith-Purcell radiation, generated when a beam of charged particles passes close to the surface of a diffraction grating, has been studied in the visible spectral range at wavelengths of 360 and 546 nm with the low emittance 855 MeV electron beam of the Mainz Microtron MAMI. The beam focused to a spot size of $4 \ensuremath{\mu}\mathrm{m}$ (full width at half maximum) passed over optical diffraction gratings of echelle profiles with blaze angles of $0.8\ifmmode^\circ\else\textdegree\fi{}, 17.27\ifmmode^\circ\else\textdegree\fi{},$ and $41.12\ifmmode^\circ\else\textdegree\fi{}$ and grating periods of 0.833 and $9.09 \ensuremath{\mu}\mathrm{m}.$ Taking advantage of the specific emission chara…
Miniature magnetic devices for laser-based, table-top free-electron lasers
2007
Truly table-top sized radiation sources based on compact laser-plasma accelerators require compact and strong focusing devices and efficient short-period undulators. Complementing our recent theoretical work on the feasibility of a table-top FEL, we here present the design and successful experimental characterizations of a 5 mm period length undulator and miniature quadrupole magnets with field gradients of the order of $500\text{ }\text{ }\mathrm{T}/\mathrm{m}$.
Progress in development of a new luminescence setup at the FinEstBeAMS beamline of the MAX IV laboratory
2019
The main funding for the FinEstBeAMS beamline has been obtained from the European Union through the European Regional Development Fund (project “Estonian beamline to MAX-IV synchrotron”, granted to the University of Tartu) and from the Academy of Finland through the Finnish Research Infrastructure funding projects ( FIRI2010 , FIRI2013 , FIRI2014 ). The authors also acknowledge the funding contributions of the University of Oulu , University of Turku , Tampere University of Technology , the Estonian Research Council ( IUT 2-25 , IUT 2-26 , PRG-111 ), as well as the Estonian Centre of Excellence in Research “Advanced materials and high-technology devices for sustainable energetics, sensorics…
Performance and characterization of the FinEstBeAMS beamline at the MAX IV Laboratory
2021
European Regional Development Fund (grant No. TK-141 HiTechDevices 2014-2020.4.01.15-0011 to University of Tartu; grant No. MAX-TEENUS 2014-2020.4.01.20-0278 to University of Tartu; grant No. Eesti Kiirekanal SLOFY11156T/1 to University of Tartu); Estonian Research Council (grant No. PRG-629 to University of Tartu); Jane & Aatos Erkko Foundation (grant No. SOFUS); Business Finland (grant No. 1464/31/2019); Academy of Finland (grant No. 319042; grant No. 326461; grant No. 326406; grant No. 320165); University of Oulu; University of Turku; Tampere University; University of Tartu.
Experimental realization of a new type of crystalline undulator.
2014
A new scheme of making crystalline undulators was recently proposed and investigated theoretically by Andriy Kostyuk, concluding that a new type of crystalline undulator would be not only viable, but better than the previous scheme. This article describes the first experimental measurement of such a crystalline undulator, produced by using Si(1-x)Ge(x)-graded composition and measured at the Mainzer Microtron facility at beam energies of 600 and 855 MeV. We also present theoretical models developed to compare with the experimental data.
Electron channeling experiments with bent silicon single crystals—a reanalysis based on a modified Fokker-Planck equation
2020
A surprising small dechanneling length was observed at (111) channeling of ultrarelativistic electrons in a 60 $\mu$m thick silicon single crystal with a bending radius of 0.15 m. The experiments were conducted at beam energies between 3.35 and 14 GeV at the Facility for Advanced Accelerator Experimental Tests (FACET at SLAC, USA). It is shown in this paper that the small dechanneling lengths can well be reproduced with a modified Fokker-Planck equation for plane crystals in which a crystal bending has been heuristically introduced. Encouraged by this result experiments have been reconsidered which were performed at the Mainz Microtron MAMI with (110) silicon undulator crystals. The results…
Channeling and Radiation of Electrons in Silicon Single Crystals and Si1−xGexCrystalline Undulators
2013
The phenomenon of channeling and the basic features of channeling radiation emission are introduced in a pedestrian way. Both, radiation spectra as well as dechanneling length measurements at electron beam energies between 195 and 855 MeV feature quantum state phenomena for the (110) planar potential of the silicon single crystals. Radiation from a crystalline undulator, produced at the Aarhus University (UAAR), has been investigated at the Mainz Microtron electron accelerator facility MAMI. The 4-period epitaxially grown strained layer Si1−xGex undulator had a period length λu = 9.9 μm. At a beam energy of 375 MeV a broad excess yield around the theoretically expected photon energy of 0.13…