Soft X-ray reflectivity and structure evaluation of Ni/C/Ti/C multilayer X-ray mirrors for water-window region

AbstractThe paper presents a brief review of recent works concerning the modeling of X-ray lasers in cluster flows and in nanostructured targets. Calculations of the atomic characteristics are based on relativistic perturbation theory with a model potential of zero approximation. Two new results are discussed: (1) it is shown that a subpicosecond X-ray laser with λ = 41.8 nm formed in a xenon cluster flow can serve as an alternative to a free-electron laser and (2) in heavy Ni-like ions ( Z ≥ 60), the ionization of ions and recombination of electrons are balanced at electronic temperatures ≥1500 eV; thus, the state of a Ni-like ion is quasi-steady-state. The inversions of many transition levels of an X-ray laser are also quasi-steady-state. The possibility of experimental observation of X-ray lasers based on 3 p ^54 d ^104 p [ J = 0] – 3 p ^63 d ^94 p [ J = 1] intrashell transitions in Gd^36+ with wavelengths in the water window region is discussed.

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Generation of a coherent x ray in the water window region at 1 kHz repetition rate using a mid-infrared pump source

Optics Letters ◽

10.1364/ol.34.001747 ◽

2009 ◽

Vol 34 (11) ◽

pp. 1747 ◽

Cited By ~ 56

Author(s):

Hui Xiong ◽

Han Xu ◽

Yuxi Fu ◽

Jinping Yao ◽

Bin Zeng ◽

...

Keyword(s):

Repetition Rate ◽

Mid Infrared ◽

X Ray ◽

Water Window ◽

Pump Source ◽

Window Region

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Towards GW-Scale Isolated Attosecond Pulse Far beyond Carbon K-Edge Driven by Mid-Infrared Waveform Synthesizer

Applied Sciences ◽

10.3390/app8122451 ◽

2018 ◽

Vol 8 (12) ◽

pp. 2451 ◽

Cited By ~ 3

Author(s):

Yuxi Fu ◽

Hua Yuan ◽

Katsumi Midorikawa ◽

Pengfei Lan ◽

Eiji Takahashi

Keyword(s):

Single Cycle ◽

High Order Harmonic Generation ◽

Mid Infrared ◽

X Ray ◽

Water Window ◽

High Order Harmonic ◽

Optical Parametric ◽

Isolated Attosecond Pulse ◽

Window Region ◽

The Continuum

We discuss the efficient generation of intense “water window” (0.28–0.54 keV) isolated attosecond pulses (IAPs) using a mid-infrared (MIR) waveform synthesizer. Our numerical simulations clearly indicate that not only a longer-wavelength driving laser but also a weak control pulse in the waveform synthesizer helps extend the continuum cutoff region and reduce the temporal chirp of IAPs in high-order harmonic generation (HHG). This insight indicates that a single-cycle laser field is not an optimum waveform for generating the shortest IAP from the veiwpoints of reducing the attochirp and increasing the efficiency of HHG. By combining a waveform synthesizer technology and a 100 mJ MIR femtosecond pulse based on a dual-chirped optical parametric amplification (DC-OPA) method, a gigawatt-scale IAP (55 as with 10 nJ order) in the water window region can be generated even without attochirp compensation. The MIR waveform synthesizer is highly beneficial for generating a shorter IAP duration in the soft X-ray region because there are no suitable transparent dispersive materials that can be used for compressing the attochirp.

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Thermal and temporal stability of V/Sc multilayer mirror for the soft X-ray water window region

Vacuum ◽

10.1016/j.vacuum.2017.09.030 ◽

2017 ◽

Vol 146 ◽

pp. 187-193 ◽

Cited By ~ 3

Author(s):

Qiang Yi ◽

Qiushi Huang ◽

Jinshuai Zhang ◽

Xiangmei Wang ◽

Runze Qi ◽

...

Keyword(s):

Temporal Stability ◽

X Ray ◽

Multilayer Mirror ◽

Water Window ◽

Window Region

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Soft X-Ray Emission in the Water Window Region with Nitrogen Filling in a Low Energy Plasma Focus

Journal of Fusion Energy ◽

10.1007/s10894-012-9536-2 ◽

2012 ◽

Vol 32 (1) ◽

pp. 121-127 ◽

Cited By ~ 2

Author(s):

M. Akel ◽

S. Lee

Keyword(s):

Plasma Focus ◽

Low Energy ◽

X Ray ◽

Water Window ◽

Window Region

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Numerical experiments on the PF1000 plasma focus device operated with nitrogen and oxygen gases

Modern Physics Letters B ◽

10.1142/s0217984917501676 ◽

2017 ◽

Vol 31 (16) ◽

pp. 1750167 ◽

Cited By ~ 1

Author(s):

M. Akel ◽

Sh. Ismael ◽

S. Lee ◽

S. H. Saw ◽

H. J. Kunze

Keyword(s):

Plasma Focus ◽

Numerical Experiments ◽

Oxygen Plasma ◽

Stored Energy ◽

X Ray ◽

Water Window ◽

Energy Formula ◽

Window Region ◽

Cooling Effects ◽

Radiative Collapse

The indicative values of reduced Pease–Braginskii (P–B) currents are estimated for a nitrogen and oxygen plasma focus. The values of depletion times indicate that in N2 and O2 with estimated 3–4% of pinch energy radiating away over the duration of the pinch, we may expect some cooling effects leading to small reductions in radius ratio. In other gases with higher atomic number, the pinch duration is much more than the depletion time, so radiative contraction may be anticipated. The Lee model was employed to study the soft X-ray from PF1000 operated with nitrogen and oxygen. We found nitrogen soft X-ray yield in the water window region of 3.13 kJ, with the corresponding efficiency of 0.9% of the stored energy [Formula: see text], while for the oxygen it was found to be [Formula: see text] = 4.9 kJ, with the efficiency of 1.4% [Formula: see text]. The very modest enhancement of compression (radius ratios around 0.1) in the pinches of these two gases gives rise to rather modest pinch energy densities (PEDs) under 109 Jm[Formula: see text]. This is in contrast to Kr or Xe where it had been shown that the radiative collapse leads to radius ratios of 0.007 and 0.003, respectively, with PEDs going to large values considerably exceeding 10[Formula: see text] Jm[Formula: see text].

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X-ray Gabor holography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100139433 ◽

1995 ◽

Vol 53 ◽

pp. 612-613

Author(s):

Steve Lindaas ◽

Chris Jacobsen ◽

Alex Kalinovsky ◽

Malcolm Howells

Keyword(s):

Surface Relief ◽

Biological Imaging ◽

Specimen Preparation ◽

X Rays ◽

X Ray ◽

Water Window ◽

Biological Objects ◽

Transmission Imaging ◽

Atomic Force ◽

Electron Microscopes

Soft x-ray microscopy offers an approach to transmission imaging of wet, micron-thick biological objects at a resolution superior to that of optical microscopes and with less specimen preparation/manipulation than electron microscopes. Gabor holography has unique characteristics which make it particularly well suited for certain investigations: it requires no prefocussing, it is compatible with flash x-ray sources, and it is able to use the whole footprint of multimode sources. Our method serves to refine this technique in anticipation of the development of suitable flash sources (such as x-ray lasers) and to develop cryo capabilities with which to reduce specimen damage. Our primary emphasis has been on biological imaging so we use x-rays in the water window (between the Oxygen-K and Carbon-K absorption edges) with which we record holograms in vacuum or in air.The hologram is recorded on a high resolution recording medium; our work employs the photoresist poly(methylmethacrylate) (PMMA). Following resist “development” (solvent etching), a surface relief pattern is produced which an atomic force microscope is aptly suited to image.

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