A low-frequency theorem on laser-assisted X-ray scattering

1992 ◽  
Vol 70 (9) ◽  
pp. 731-739 ◽  
Author(s):  
F. Ehlotzky
Keyword(s):  
Low Frequency ◽  
Potential Scattering ◽  
Quantum Mechanical ◽  
Free Electrons ◽  
X Ray ◽  
Classical Counterpart ◽  
Frequency Theorem ◽  
X Ray Scattering ◽  
Cross Section Formula ◽  
Ray Scattering

As we shall show, for laser-assisted X-ray scattering by free electrons, a similar low-frequency theorem can be derived, as was found many years ago by Kroll and Watson, for potential scattering of electrons in a laser field. If quantum mechanical recoil effects are neglected, our renormalized cross-section formula becomes independent of Planck's constant and therefore must have a classical counterpart.

scholarly journals Ultra-high-resolution inelastic X-ray scattering at high-repetition-rate self-seeded X-ray free-electron lasers

2016 ◽  
Vol 23 (2) ◽  
pp. 410-424 ◽  
Author(s):  
Oleg Chubar ◽  
Gianluca Geloni ◽  
Vitali Kocharyan ◽  
Anders Madsen ◽  
Evgeni Saldin ◽  
...  
Keyword(s):  
High Resolution ◽  
Low Frequency ◽  
Fold Increase ◽  
High Repetition Rate ◽  
X Ray ◽  
Equilibrium Dynamics ◽  
X Ray Scattering ◽  
Radiation Sources ◽  
Spectral Flux ◽  
Ray Scattering

Inelastic X-ray scattering (IXS) is an important tool for studies of equilibrium dynamics in condensed matter. A new spectrometer recently proposed for ultra-high-resolution IXS (UHRIX) has achieved 0.6 meV and 0.25 nm−1spectral and momentum-transfer resolutions, respectively. However, further improvements down to 0.1 meV and 0.02 nm−1are required to close the gap in energy–momentum space between high- and low-frequency probes. It is shown that this goal can be achieved by further optimizing the X-ray optics and by increasing the spectral flux of the incident X-ray pulses. UHRIX performs best at energies from 5 to 10 keV, where a combination of self-seeding and undulator tapering at the SASE-2 beamline of the European XFEL promises up to a 100-fold increase in average spectral flux compared with nominal SASE pulses at saturation, or three orders of magnitude more than what is possible with storage-ring-based radiation sources. Wave-optics calculations show that about 7 × 1012 photons s−1in a 90 µeV bandwidth can be achieved on the sample. This will provide unique new possibilities for dynamics studies by IXS.

Low-frequency Raman scattering and small-angle X-ray scattering of glasses inclined to phase decomposition

1999 ◽  
Vol 243 (2-3) ◽  
pp. 244-250 ◽  
Author(s):  
T.I Chuvaeva ◽  
O.S Dymshits ◽  
V.I Petrov ◽  
M.Ya Tsenter ◽  
A.A Zhilin ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Small Angle ◽  
Low Frequency ◽  
Phase Decomposition ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

Time-Resolved Cryo-Electron Microscopy of Oscillating Microtubules

1990 ◽  
Vol 48 (1) ◽  
pp. 502-503
Author(s):  
Eva-Maria Mandelkow ◽  
Ron Milligan
Keyword(s):  
Electron Microscopy ◽  
Dynamic Instability ◽  
Entire Solution ◽  
Reaction Scheme ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
A Chain ◽  
Ray Scattering

Microtubules form part of the cytoskeleton of eukaryotic cells. They are hollow libers of about 25 nm diameter made up of 13 protofilaments, each of which consists of a chain of heterodimers of α-and β-tubulin. Microtubules can be assembled in vitro at 37°C in the presence of GTP which is hydrolyzed during the reaction, and they are disassembled at 4°C. In contrast to most other polymers microtubules show the behavior of “dynamic instability”, i.e. they can switch between phases of growth and phases of shrinkage, even at an overall steady state [1]. In certain conditions an entire solution can be synchronized, leading to autonomous oscillations in the degree of assembly which can be observed by X-ray scattering (Fig. 1), light scattering, or electron microscopy [2-5]. In addition such solutions are capable of generating spontaneous spatial patterns [6].In an earlier study we have analyzed the structure of microtubules and their cold-induced disassembly by cryo-EM [7]. One result was that disassembly takes place by loss of protofilament fragments (tubulin oligomers) which fray apart at the microtubule ends. We also looked at microtubule oscillations by time-resolved X-ray scattering and proposed a reaction scheme [4] which involves a cyclic interconversion of tubulin, microtubules, and oligomers (Fig. 2). The present study was undertaken to answer two questions: (a) What is the nature of the oscillations as seen by time-resolved cryo-EM? (b) Do microtubules disassemble by fraying protofilament fragments during oscillations at 37°C?

X-ray scattering by 1D molecular Guinier-Preston zones in ordered smectic phases

1992 ◽  
Vol 2 (6) ◽  
pp. 899-913 ◽  
Author(s):  
Patrick Davidson ◽  
Elisabeth Dubois-Violette ◽  
Anne-Marie Levelut ◽  
Brigitte Pansu
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Smectic Phases ◽  
Ray Scattering

An X-ray Scattering Study of Laterally Modulated Structures: Investigation of Coherence and Resolution Effects with a Grating

1996 ◽  
Vol 6 (8) ◽  
pp. 1085-1094 ◽  
Author(s):  
A. Gibaud ◽  
J. Wang ◽  
M. Tolan ◽  
G. Vignaud ◽  
S. K. Sinha
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Modulated Structures ◽  
Scattering Study ◽  
Ray Scattering

Pixel detectors: New detectors for X-ray scattering

2002 ◽  
Vol 12 (6) ◽  
pp. 385-390 ◽  
Author(s):  
J.-F. Bérar ◽  
L. Blanquart ◽  
N. Boudet ◽  
P. Breugnon ◽  
B. Caillot ◽  
...  
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Pixel Detectors ◽  
Ray Scattering

SHORT RANGE ORDER DETERMINATION IN AMORPHOUS FeGe2 WITH ANOMALOUS X-RAY SCATTERING

1985 ◽  
Vol 46 (C8) ◽  
pp. C8-187-C8-191
Author(s):  
R. D. Lorentz ◽  
A. I. Bienenstock
Keyword(s):  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
X Ray ◽  
X Ray Scattering ◽  
Order Determination ◽  
Ray Scattering
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