Reflection zone plate wavelength-dispersive X-ray spectrometry

Seminars
11.02.2018
14:30
David Wang Auditorium, 3rd floor Dalia Maydan Bldg.
Prof. Dr. Alexey Erko

Prof. Dr. Alexey Erko

Helmholtz-Zentrum Berlin für Materialien und Energie GmbH. Department for Nanometer Optics and Technology ,Albert Einstein Str. 15, 12489 Berlin, Germany alexei.erko@helmholtz-berlin.de

 

The first successful practical implementation of a total reflection zone plate (TRZP) as a monochromator-spectrometer at the femto-slicing synchrotron radiation beamline was done in 2008 [1]. The 20 times higher transmittance and a pulse elongation on the order of 30 fs with an energy resolution similar to a conventional plane grating monochromator beamline attract many in-house and external users to perform their high-ranking experiments at the BESSY II facility. In 2014, the beamline was upgraded and presently can cover an energy range of 300 eV to 1200 eV continuously, with parallel recording of XANES spectra of elements with a time resolution down to ~ 100 fs [2]. The principle of a combination of three functions in one optical element (reflection, energy dispersion and focusing) was extended for the development of a new generation of spectrometers for fs-spectroscopy on highly diluted materials [3], fs monochromators for high harmonic generators (HHG)[4], and laser-plasma X-ray sources [5].

In the class of laboratory instrumentation, the multi-channel RZP fluorescence spectrometer for the scanning electron micro- scope has shown unique performances in the energy range of 40 eV to 1000 eV [6]. In this talk also will be reported on a new type of a time-delay compensated monochromator (TDCM) with a pulse elongation below 5 fs at the photon energy of 450 eV, continuously tuning in the energy range of 100 eV – 1000 eV. The TDCM which consists of two identical 2D VLS gratings is settled up in opposite diffraction orders provides up to order of magnitude higher efficiency.

References:
[1] A. Erko et al., AIP Conference Proceedings 1234, (2010) 177
[2] K. Holldack, et al., Journal of Synchrotron Radiation, 21, (2014) 1090.
[3] R. Mitzner et al., The Journal of Physical Chemistry Letters, 4, (2013) 3641
[4] J. Metje et al., Optics Express, 22(9), (2014), 10747
[5] I. Mantouvalou et al., Applied Physics Letters, 108, (2016) 201106
[6] A. Hafner et al., Optics Express, 23(23), (2015) 29476

Host: Professor Emeritus Emil Zolotoyabko