Nuclear resonant forward scattering

Fig. 9.25 Time dependence of the nuclear resonant forward scattering by the complex [Fe (CH3COO)(TPpivP)] measured in an external field of 4 T applied perpendicular to k and tr at the temperatures indicated. (Taken from [30])...

Nuclear resonant forward scattering and inelastic scattering of synchrotron radiation constitute a promising field for development of catalyst characterization in the future. For the characterization of solid catalysts, NFS has the advantage over... 

M. Haas, et al., Nuclear resonant forward scattering of synchrotron radiation by randomly oriented iron complexes which exhibit nuclear Zeeman interaction, Phys. Rev. B 1997, 56(21), 14082-14088. 

Winkler H, Chumakov AI, Trautwein AX (2004) Nuclear Resonant Forward and Nuclear Inelastic Scattering Using Synchrotron Radiation for Spin Crossover Systems. 235 105-136... 

Nuclear Resonant Forward and Nuclear Inelastic Scattering Using Synchrotron Radiation for Spin Crossover Systems... 

Leupold et al. were the first to report on coherent nuclear resonant scattering of synchrotron radiation from the 67.41 keV level of Ni. The time evolution of the forward scattering was recorded by employing the so-called nuclear lighthouse... 

Ta foil Nuclear forward scattering of synchrotron radiation (NFS) at Ta resonance in Ta foil without and with applied magnetic field, point out advantages over conventional Ta Mossbauer spectroscopy... 

Ta metal Stroboscopic detection of nuclear forward scattered synchrotron radiation is used to detect the high-resolution 6.2 keV Mossbauer resonance of Ta in Ta metal... 

All these techniques are referred to as nuclear resonance scattering (NRS) of synchrotron radiation they include a wide spectrum of experimental techniques, such as nuclear forward scattering (NFS), nuclear inelastic scattering (NIS), nuclear... 

CEMS = conversion electron Mossbauer spectroscopy DFT = density functional theory EFG = electric field gradient EPR = electron paramagnetic resonance ESEEM = electron spin echo envelope modulation spectroscopy GTO = Gaussian-type orbitals hTH = human tyrosine hydroxylase MIMOS = miniaturized mossbauer spectrometer NFS = nuclear forward scattering NMR = nuclear magnetic resonance RFQ = rapid freeze quench SAM = S -adenosyl-L-methionine SCC = self-consistent charge STOs = slater-type orbitals TMP = tetramesitylporphyrin XAS = X-ray absorption spectroscopy. 

Schematic for measurement of the nuclear resonance excitation accompanied by phonon excitation. The avalanche photodiode (APD) detector placed below the sample detects inelastic scattering, and another APD detector in the forward direction detects forward scattering for the energy reference...

In a nuclear resonant scattering experiment all resonant levels of the Mossbauer nuclei in the sample are simultaneously excited by a short pulse of synchrotron radiation, creating the nuclear exciton. The time dependence of the delayed intensity emitted upon de-excitation of the nuclear exciton in forward direction is the time spectrum of nuclear forward scattering (NFS). 

In general, the time dependence of the nuclear forward scattering comprises both quantum and dynamical beats, as depicted in Fig. l.lOf for the case of electric quadrupole interaction. If the resonances are well separated, the time development of the amplitude of nuclear forward scattering from a sample of thickness d can be expressed as [22]... 

A schematic of the principles and experimental setups for conventional Mossbauer spectroscopy (left) and SR-based NFS (right). In conventional Mossbauer spectroscopy, a 7-ray is generated by a radioactive source f Co for Fe Mossbauer). A driver system is attached to the source to provide a Doppler shift to the energy to the emitted 7-ray. This 7-ray can be resonantly absorbed in the sample. The transmitted 7-ray intensity is registered in the detector as a function of Doppler velocity. In SR-based NFS, millielectron volt bandwidth 7 radiation is provided by synchrotron radiation and subsequent monochromators. This pulse coherently excites different nuclear transitions in the sample. The forward-scattered signal generated from the nuclear excited states is registered in the detector placed in the forward direction as a function of time. 

Fig. 1.10 Coherent excitation and coherent de-excitation of the nucleus for the nuclear forward scattering and the nuclear Bragg scattering. Coherent de-excitation of the resonant scattering creates the quantum beat with a frequency of Q...

This overview covers the major teclnhques used in materials analysis with MeV ion beams Rutherford backscattering, chaimelling, resonance scattering, forward recoil scattering, PIXE and microbeams. We have not covered nuclear reaction analysis (NRA), because it applies to special incident-ion-target-atom combinations and is a topic of its own [1, 2]. 

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