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1.
Anton A. Akhsakhalyan Aram D. Akhsakhlyan Alexander I. Kharitonov Eugenie B. Kluenkov Vladimir A. Murav’ev Nikolay N. Salashchenko 《Central European Journal of Physics》2005,3(2):163-177
This paper is an overview of the research activities carried out in the past five years at the Institute for Physics of Microstructures
RAS and “X-ray” Company towards the manufacture of multilayer mirror systems capable of forming X-ray beams in the subnanometer
range of wavelengths. The systems fabrication technology is presented, including techniques for producing supersmooth surfaces
of specified shape, methods of graded multilayer structure deposition on such surfaces, and the principles of designing optimal
mirror parameters. The characteristics of a quadrelliptical reflector—a novel high light-gathering power four-corner focusing
system—are reported. 相似文献
2.
P. S. Antsiferov 《Central European Journal of Physics》2003,1(2):268-288
The article presents the results of a study of characteristic X-ray spectra of free atoms by means of a new simple technique.
A pulsed electron beam was used for evaporation and to create inner-shell vacancies in free atoms of metals. The spectra were
obtained with the help of an X-ray monochromator which allowed precise comparison between the free-atoms spectra and corresponding
solid-state spectra. The shifts of the peaks were measured and found to be in the range Δλ/λ≈10−5–10−4. The K-, L- and M-series spectra were studied. A number of the free-atoms spectra revealed structure which was not resolved
in the solid-state spectra and which is of interest for atomic structure calculation applications. This electron beam technique
for the investigation of X-ray characteristic spectra of free atoms can be used for the refinement of X-ray wavelength standards. 相似文献
3.
An optic-based X-ray tomography system of a high spatial resolution using a conventional X-ray tube was proposed. The system had several X-ray optics: multilayer mirror for monochromatic X-ray, capillary optic for focusing X-ray onto a sample, and objective zone plate. The X-ray tomography system was designed for obtaining a spatial resolution of 100 nm. Design parameters for each optic were determined and optimized by ray tracing in considering X-ray intensity and reflectivity. The X-ray tomography system with a spatial resolution of 100 nm will provide a good inspect tool in bio-medical field and semiconductor applications. 相似文献
4.
T. Matsuzaki K. Nagamine K. Ishida S.N. Nakamura N. Kawamura M. Tanase M. Kato K. Kurosawa M. Hashimoto H. Sugai K. Kudo N. Takeda G.H. Eaton 《Hyperfine Interactions》1999,118(1-4):229-234
X-ray and neutron measurements were carried out for muon catalyzed fusion and related phenomena in solid T2. The X-ray originated from the μ- to α sticking in muon catalyzed fusion; t + t + μ
-
→ (μ
-
α) + 2n was measured for the first time, yielding K
α
X-ray intensity of (μα) atom and the intensity ratio of K
β
to K
α
. Utilizing the phenomena of 3He accumulation in solid T2, the X-ray in the μ- transfer process from (tμ) to 3He was detected, providing a formation rate and radiative decay branching-ratio of (t
3Heμ) molecule. From fusion neutron measurements, estimated values were obtained for (ttμ) molecular formation rate as well as sticking probability ωt in ttμ fusion. A possible new insight in t + t fusion reaction process at a low energy limit is also obtained.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
Krishnamurthy V. V. Suzuki M. Kawamura N. Ishikawa T. Kohori Y. 《Hyperfine Interactions》2001,136(3-8):361-365
The formation of an induced 5d magnetic moment on Ir in Fe97Ir3, Co95Ir5 and Ni95Ir5 alloys has been investigated by X-ray magnetic circular dichroism (XMCD) and X-ray absorption spectra (XAS) measurements
at Ir L
2,3 edges. Using a sum rule which relates the integrals of these spectra with the ground state expectation value of the orbital
angular momentum 〈L
Z
〉 of the probed atom, the orbital moment m
orb of Ir could be determined as −0.071(2) μ
B
in an Fe host, −0.067(2) μ
B
in a Co host and −0.041(1) μ
B
in a Ni host. The spin magnetic moment m
spin of Ir is also found to be the maximal in Fe and the minimal in Ni. The total moment of Ir is found to be approximately 1/5
of total moment of Fe, 2/13 of the total moment of Co, and 1/4 of the total moment of Ni.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
6.
L-shell photoelectric cross sections have been measured at 60 keV for six elements in the range 74≤Z≤92. The measurements are found to agree with theoretical calculations. 相似文献
7.
I. A. Artyukov A. V. Vinogradov Ye. A. Bugayev A. Yu. Devizenko V. V. Kondratenko Yu. S. Kasyanov 《Journal of Experimental and Theoretical Physics》2009,109(5):872-884
This paper reports on the fabrication and testing of multilayer mirrors for X-ray optical systems operating in the “carbon
window” region (at wavelengths from 4.5 to 5.0 nm) and the results of their application in soft X-ray imaging of the internal
structure of organic objects. The developed approaches to the fabrication and control of graded Co/C multilayer coatings have
made it possible to create an X-ray multimirror system with a maximum known entrance aperture and throughput. The use of the
developed high-spatial-resolution X-ray optics can significantly extend the field of practical application of soft X-ray absorption
microscopy based on compact laser-plasma sources. 相似文献
8.
Y. Ménesguen S. de Rossi E. Meltchakov F. Delmotte 《Applied Physics A: Materials Science & Processing》2010,98(2):305-309
Recent extreme ultraviolet sources using high-harmonic generation in a rare gas make new optics developments necessary. We
report on the study and development of multilayer structures with efficient reflectivity in the 35–75 eV energy range. We
have optimized, deposited and characterized two aperiodic broadband mirrors consisting of a Mo, Si and B4C thin-film stack. We used the needle procedure in order to optimize mirror reflectivity. The magnetron sputter deposited
multilayers have been calibrated and characterized using Cu K
α
grazing incidence X-ray reflectometry. Reflectivity measured at near-normal incidence on a synchrotron radiation source reaches
12% with a full width at half maximum of nearly 40 eV. Experimental results are compared with theoretical simulation using
available optical constants for Mo, Si and B4C in this spectral range. 相似文献
9.
Alexander G. Andreev Stefka G. Tsintsarska Maria Dimitrova-Ivanovich Ivaylo Polyanski Mladen Georgiev Alexander D. Gochev 《Central European Journal of Physics》2004,2(2):329-356
The temperatureT dependencies ρ(T) of normal state electric resistivitiesρ
c
(axial) andρ
ab
(in plane) of single-layer high-T
c
superconductors show common trends: AsT is raised, the resistivity first drops steeply before it starts rising αT above an apparent semiconductor-to-metal crossoverT
cross
. To analyze ρ(T) we plottT/ρ againstT at various dopingsx for bothρ
c
andρ
ab
.T/ρ is inversely proportional to the traversal time across a potential barrier as an ionic particle drifts in an electric field.
We findT/ρ in good agreement with theT dependence of the quantum rate of migrating particles: AsT is raised, a zero-point rate at the lowestT is extended to a nearly flat plateau before a thermally activated branch sets in. We also find evidence for the admixture
of 1- & 2-phonon absorptions below the Arrhenius range. These features shape the semiconductor-like branch below T
cross
. AboveT
cross
a metallic-like branch sets in, its αT character deriving from the field coupling of the migrating particle. Our analysis suggests that metal physics may not suffice
if ionic features play a role in transport. We attribute our conclusions to the drift of strong-coupling polarons along Cu−O
bonds. These “bond polarons” originate from carrier scattering by double-well potentials associated with the bonds. A bond
polaron dissociates to a free hole as it passes onto a neighboring O-O link. 相似文献
10.
Pawel Horodecki 《Central European Journal of Physics》2003,1(4):695-707
We consider the problem of invariance of distillable entanglement D and quantum capacities Q under erasure of information about single copy of quantum state or channel respectively. We argue that any 2 ⊗N two-way distillable state is still two-way distillable after erasure of single copy information. For some known distillation
protocols the obtained two-way distillation rate is the same as if Alice and Bob knew the state from the very beginning. The
isomorphism between quantum states and quantum channels is also investigated. In particular it is pointed out that any transmission
rate down the channel is equal to distillation rate with formal LOCC-like superoperator that uses in general nonphysical Alice
actions. This allows to we prove that if given channel Λ has nonzero capacity (Q
→ or Q
⟺) then the corresponding quantum state ϱ(Λ) has nonzero distillable entanglement (D
→ or D
⟺). Follwoing the latter arguments are provided that any channel mapping single qubit into N level system allows for reliable two-way transmission after erasure of information about single copy. Some open problems
are discussed. 相似文献
11.
Aurélie Rolle Helen Seymour Pascal Roussel Annick Rubbens Rose-Noëlle Vannier 《Ionics》2008,14(6):477-482
The Ba2In2 − x
Sn
x
O5 + x/2 solid solution was confirmed up to x = 1 by solid-state reaction. X-ray diffraction at room and at elevated temperatures, Raman scattering and impedance spectroscopy
were used to characterise the samples. The structure refinement of the composition x = 0.1 from neutron diffraction data reveals that tin is preferentially located in the tetrahedral layers of the brownmillerite.
Paper presented at the 11th EuroConference on the Science and Technology of Ionics, Batz-sur-Mer, Sept. 9–15, 2007 相似文献
12.
V. Egorov V. Brudanin K. Gromov A. Klinskih M. Shirchenko Ts. Vylov I. Yutlandov D. Zinatulina Ch. Briançon C. Petitjean O. Naviliat-Cuncic 《Czechoslovak Journal of Physics》2006,56(5):453-457
Gamma-rays following nuclear capture of negative muons in enriched 48Ti, 76Se, 106Cd, as well as natural Se and Cd targets were measured. Time evolution of several gamma-lines allowed to deduce the total
μ-capture rates in Ti, Se and Cd isotopes, which are compared to the Primakoff estimate. The data on the partial μ-capture rates will be used for more precise calculation of the 2β-NMEs of 48Ca, 76Se and 106Cd.
Presented by V. Egorov at the Workshop on calculation of double-beta-decay matrix elements (MEDEX’05), Corfu, Greece, September
26–29, 2005.
Partly supported by the Russian Foundation for Basic Research (grant 06-02-16587). 相似文献
13.
L-shell photoelectric cross-sections have been measured at 6 keV for eight elements in the range 40⩽Z⩽53. The measurements
agree with theoretical calculations. 相似文献
14.
Experimental Coulomb isotope shifts δE
Coul from K
α transitions, and radius differences δ〈r
2〉
eμ measured by electron scattering and muonic atom X-rays were used to derive ‘experimental’ coefficients C
1,exp for 54 isotope pairs of 18 elements from Mo to U. A χ2-analysis shows that these experimental coefficients are – on average – 3.5% lower than the theoretical C
1 values calculated by Seltzer, or more precisely: C
1,exp=0.965(± 0.014)×C
1. The need for more accurate theoretical calculations is stressed, and consequences of this deviation are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
Electron-doped (Ba1−x
La
x
)MnO3 compounds were prepared for x=0−0.5. Measurements of X-ray diffraction (XRD) at room temperature and temperature variation of dc electrical resistivity
down to 20 K were carried out. Samples with x=0.2–0.5 exhibit metal-insulator (M-I) transition. The maximum M-I transition temperature (T
c) of 289 K was observed for 30% of La doping (x=0.3). XRD patterns of these samples (x=0.2−0.5) were analyzed using Rietveld refinement. These samples are found to be mostly in single-phase form with orthorhombic
symmetry (space group Pbnm). We have found strong correlation between Mn-O-Mn bond angles and T
c of M-I transition. The resistivity data below T
c could be fitted to the expression ρ=ρ
1+ρ
2
T
2 and this shows that double exchange interaction plays a major role even in Mn4+-rich compound. Above T
c the resistivity data were fitted to variable range hopping and small polaron models. 相似文献
16.
Yong-Yeon Keum 《Pramana》2004,63(6):1151-1170
We discuss applications of the perturbative QCD approach in the exclusive non-leptonic two-bodyB-meson decays. We briefly review its ingredients and some important theoretical issues on the factorization approach. PQCD
results are compatible with present experimental data for charmless B-meson decays. We predict the possibility of large direct
CP asymmetry in B0 → π+π− (23 +7%) and B0 →K
+π− (− 17 ± 5%). We also investigate the branching ratios, CP asymmetry and isospin symmetry breaking in radiativeB →(K*/ρ)γ decays. 相似文献
17.
Kβ X-ray spectra of Si and SiO2 have been measured accurately with a double crystal spectrometer. The measuredKβ spectrum of silicon element was compared with calculations of the electronic density of states.
Observed intensity distribution shows that thep-electrons predominate at the top of the valence band, and somep-like states extend to the middle of the valence band. According to MO calculations the most intensiveKβ line of SiO2 is 4t
2 (100), the 3t
2 (16) line is 17.9 eV lower, and 5t
2 (5) line 6.3 eV higher. In our measurements the energy differences are 13.0 and 4 eV, respectively, and intensities 30% and
3% from the main line. 相似文献
18.
19.
The electronic structure of La1–x
Ga
x
MnO3+δ. solid solutions is studied by X-ray photoelectron spectroscopy (XPS). The valence state of the manganese is estimated by
various methods: by analyzing the difference in the binding energies of the Mn2p3/2 and O1s electronic levels, analyzing exchange splitting in the spectrum of Mn3s, and from the dependence of the binding energy
of the XPS spectrum of Mn2p3/2 on the calcium concentration. The state of oxidation of the manganese in the compositions containing calcium lies between
Mn3+ and Mn4+. The efficacies of these methods are compared. A correlation is found between the type of crystalline structure of La1–x
Ga
x
MnO3+δ. (0 ≤ x < 1) and the binding energy of the Mn2p3/2 peak.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 3, pp. 419–427, May–June, 2009. 相似文献
20.
G A V Ramanamurthy K Ramachandra Rao Y Rama Krishna P Venkateswarlu K Bhaskara Rao P V Ramana Rao S Venkata Ratnam V Seshagiri Rao G J Nagaraju S Bhuloka Reddy 《Pramana》2001,56(5):697-703
The Measurement of K
β
K
/α
intensity ratios are measured in some 3d shell elements by using a 2 MeV proton beam along with a high resolution Si(Li) detector. The present Measurement of K
β
K
/α
intensity ratios are in good agreement with Scofield modified theoretical values, thus supporting the basic assumptions in
that theory. From the present Measurement of K
β
K
/α
intensity ratios, it is evident that due to chemical effects, the experimental Measurement of K
β
K
/α
intensity ratios will be increased while they will be decreased due to the presence of simultaneous M-shell vacancies which are produced due to proton excitation. 相似文献