Measurement of Coherent Transition X Rays

Moran, M. J.; Dahling, B. A.; Ebert, P. J.; Piestrup, M. A.; Berman, B. L.; Kephart, J. O.

doi:10.1103/physrevlett.57.1223

Cited by 44 publications

(12 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fabjan and Struczinski [4] and others [5 -8] have shown resonance by observing the photon-energy spectrum which was broken up into modes of smaller bandwidth. In an early experiment at the Lawrence Livermore National Laboratory (LLNL), we showed that phase coherence of ultrasoft x rays (150 eV) resulted in an unusual spatial interference pattern as predicted by resonance transition radiation [9]. In experiments presented here, we have observed the angular radiation pattern from coherent, or resonant, transition radiation (RTR) at soft-x-ray energies of 800 eV to 3 keV.…”

mentioning

confidence: 62%

“…This interference shows that the x rays are generated coherently by the entire radiator structure. The radiation is termed coherent because the x rays generated are a simultaneous response of the entire radiator structure to each incident electron [9].…”

mentioning

confidence: 99%

“…The first factor F1 is the contribution from a single interface and is given by [ [9,10]. However, we can make the r =1 mode dominate by choosing r =m =1, and limiting the angle of peak emission to 0(8"(0.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Observation of soft-x-ray spatial coherence from resonance transition radiation

et al. 1992

Self Cite

View full text Add to dashboard Cite

We have observed the spatial distribution of coherent or resonance transition radiation (RTR) in the soft-x-ray region of the spectrum (1 -3 keV). Resonance transition radiators were constructed and tested at two accelerators using electron-beam energies ranging from 50 to 228 MeV. These radiators emitted soft x rays in a circularly symmetrical annulus with a half-angle divergence of 2.5-9.0 mrad. The angle of peak emission was found to increase with electron-beam energy, in contrast to the incoherent case, for which the angle of emission varied inversely with electron-beam energy. By careful selection of foil thickness and spacing, one may design radiators whose angle of emission varies over a range of chargedparticle energies. A particular RTR mode (r =m =1) was found to give a sharp annular ring that becomes more accentuated as the number of foils is increased. The RTR effect has application in particle detection, beam diagnostics, x-ray source brightness enhancement, and x-ray free-electron-laser emission.

show abstract

mentioning

confidence: 62%

mentioning

confidence: 99%

See 1 more Smart Citation

Observation of soft-x-ray spatial coherence from resonance transition radiation

et al. 1992

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the standard theory of XTR [8][9][10][11] two interfering XTR waves are emitted at both entrance and exit of the radiator by a charged particle moving with a constant velocity. For RHI the influence of slowing-down (ionization energy loss) is not negligible -the RHI velocity decreases during its penetration into a radiator, therefore, two XTR waves are emitted at slightly different velocities when crossing the vacuum-radiator and radiator-vacuum boundaries.…”

Section: Introductionmentioning

confidence: 99%

Interference effects in angular and spectral distributions of X-ray Transition Radiation from Relativistic Heavy Ions crossing a radiator: Influence of absorption and slowing-down

Fiks

Pivovarov

2015

Nuclear Instruments and Methods in Physics Research Section B:

View full text Add to dashboard Cite

“…[27]. It was suggested more than fifteen years ago by Moran et al [28] that the interfoil coherence of TR, generated by relativistic electrons, constitutes a new technique for the measurement of the refractive index decrement δ(ω) in the X-ray region. A number of experiments were performed in the soft and hard X-ray region in which more or less clear interference structures were observed [28,29,30,31,32,1].…”

Section: The Hard X-ray Interferometermentioning

confidence: 99%

Coherent X-rays at MAMI

et al. 2006

View full text Add to dashboard Cite

Abstract. Coherent radiation in the range from soft X-rays up to hard X-rays, produced by the lowemittance electron beam of MAMI, can be used for various applications. Novel types of interferometers have been developed for the measurement of the complex index of refraction of thin self-supporting foils. For the vacuum ultraviolet and soft X-ray region the interferometer consists of two collinear undulators, and a grating spectrometer. A foil placed between the undulators causes a phase shift and an attenuation of the oscillation amplitude. The complex index of refraction has been measured at the L 2,3-absorption edges of nickel. A novel method is described for the measurement of the X-ray magnetic circular birefringence. For the hard X-ray region the interferometer consists of two foils at which the 855 MeV electron beam produces transition radiation. Distinct interference oscillations have been observed as a function of both, the photon emission angle and the distance between the foils. The refractive index decrement δ(ω) of a 2 µm thick nickel sample foil has been measured at X-ray energies around the K absorption edge at 8333 eV and at 9930 eV with an accuracy of better than 1.5 %. The line width of parametric X radiation (PXR) was measured in backward geometry with a Si single-crystal monochromator. Upper limits of the line width of 42 meV, 50 meV, and 44 meV, have been determined for the (333), (444) and (555) reflections at photon energies of 5932 eV, 7909 eV, and 9887 eV, respectively. Small angle scattering of the electrons in the crystal leads to a stochastic frequency modulation of the exponentially damped wave train which results in the line broadening. To elucidate the quest if the production of PXR is a kinematical or a dynamical process the radiation from silicon single-crystal targets, emitted close to the electron direction, has been studied. The observed interference structures and the narrow-band radiation in forward direction shows that PXR is produced in a dynamical process. .Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity) -41.60.-m Radiation by moving charges -41.50.+h X-ray beams and X-ray optics PACS.

show abstract

Measurement of Coherent Transition X Rays

Cited by 44 publications

References 4 publications

Observation of soft-x-ray spatial coherence from resonance transition radiation

Observation of soft-x-ray spatial coherence from resonance transition radiation

Interference effects in angular and spectral distributions of X-ray Transition Radiation from Relativistic Heavy Ions crossing a radiator: Influence of absorption and slowing-down

Coherent X-rays at MAMI

Contact Info

Product

Resources

About