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1.
Yu. A. Belkova Ya. A. Teplova 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(6):674-677
A semi-empirical method for establishing of the average charge of ions passing through thin celluloid films is proposed. Calculations for helium (He) and nitrogen (N) ions with different initial velocities (12?18.7 × 108 cm/s for He and 4?12 × 108 cm/s for N) are presented. The equilibrium thickness of a celluloid target in dependence on the initial charge states of incident ions is evaluated. 相似文献
2.
Yu. A. Belkova Ya. A. Teplova 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(2):234-238
Analytical expressions for nonequilibrium charge fractions and the dependence of the average ion charge on the target thickness are derived on the basis of a three-component approximation. Calculations for B i+ and N i+ ions with velocities of 12 × 108 cm/s (E = 0.75 MeV/nucleon) upon passing through thin organic films (celluloid) are conducted. The calculation results are in agreement with experimental data within the accuracy of measurement (2–5%). 相似文献
3.
I. S. Dmitriev Ya. A. Teplova Yu. A. Belkova N. V. Novikov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2008,2(2):270-273
Based on experimental data on the ion charge distributions, the cross sections of single electron loss σ i, i + 1 and single electron capture σ i, i ? 1 by carbon ions with velocities (2.7–8) × 108 cm/s in different gaseous media (He, N2, and Ar) have been obtained. Regularities of the cross section variation of the electron capture and loss by carbon ions as a function of the ion velocity, ion charge, and atomic number of the target have been for the first time studied in a wide range of the initial ion charge, from i = 0 to i = 6. A qualitative agreement of the obtained results with the published data has been established for a number of other ions. Theoretical calculations of the cross sections of single electron loss by carbon ions in helium have been carried out. 相似文献
4.
Yu. A. Belkova Ya. A. Teplova 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2014,8(2):201-205
The dependences between the energy losses of beryllium ions penetrating through thin organic (celluloid) films and the initial ion charge i 0 and target thickness t are calculated. The proposed modified method is used to determine the charge fractions and average charge of an ion beam and the half-width and skewness of the charge distributions before the attainment of charge equilibrium. Calculations are performed for Be i+ ions with a velocity of 8 × 108 cm/s (E = 0.33 MeV/nucleon). 相似文献
5.
P. Delheij L. Blomeley M. Froese G. Gwinner V. Ryjkov M. Smith J. Dilling 《Hyperfine Interactions》2006,173(1-3):123-131
The TITAN facility at TRIUMF-ISAC will use four ion traps with the primary goal of determining nuclear masses with high precision, particularly for short lived isotopes with lifetimes down to approximately 10 ms. The design value for the accuracy of the mass measurement is 1 ×10???8. The four main components in the facility are an RF cooler/buncher (RFCT) receiving the incoming ion beam, an electron beam ion trap (EBIT) to breed the ions to higher charge states, a cooler Penning trap (CPET) to cool the highly charged ions, and finally the measurement Penning trap (MPET) for the precision mass determination. Additional goals for this system are laser spectroscopy on ions extracted from the RFCT and beta spectroscopy in the EBIT (in Penning trap mode) on ions that are purified using selective buffer gas cooling in the CPET. The physics motivation for the mass measurements are manifold, from unitarity tests of the CKM matrix to nuclear structure very far from the valley of stability, nuclear astrophysics and the study of halo-nuclei. As a first measurement the mass of 11Li will be determined. With a lifetime of 8.7 ms and a demonstrated production rate of 4×104 ions/sec at ISAC the goal for this measurement at TITAN is a relative uncertainty of 5×10???8. This would check previous conflicting measurements and provide information for nuclear theory and models. 相似文献
6.
Zhangxing He Lei Chen Yaoyi He Chen Chen Yifan Jiang Zhen He Suqin Liu 《Ionics》2013,19(12):1915-1920
Influence of In3+ ions on electrochemical performance of positive electrolyte for vanadium redox flow battery was investigated in this paper. The electrochemical activity and kinetics of V(IV)/V(V) redox couple can be enhanced by the addition of In3+ ions, and the optimal concentration of In3+ ions was found at 10 mM. At this condition, the oxidation peak current with 10 mM In3+ ions is 46.6 mA at a scan rate of 20 mV s?1, larger than that of pristine electrolyte (41.8 mA), and the standard rate constant is 6.53?×?10?5 cm s?1, 42 % larger than that of the pristine electrolyte (4.58?×?10?5 cm s?1). The cell using electrolyte with 10 mM In3+ ions was assembled, and the charge–discharge performance was evaluated, and the average energy efficiency increases by 1.9 % compared with the pristine cell. The improved electrochemical performance may be ascribed to that In3+ ions change the hydration state of vanadium ions in electrolyte and promote charge transfer process. 相似文献
7.
Pioneering theoretical data for single-electron charge transfer and excitations due to collisions between Bi4+ ions in the ground (6s) and metastable (6p) states are gained in the collision energy interval 5–75 keV in the center-of-mass frame. The cross sections of the processes are calculated in terms of the close-coupling method in the basis of two-electron quasi-molecular states for the Coulomb trajectory of nuclei. It is found that single-electron capture into the singlet 6s 2 states of Bi3+ ions makes a major contribution to the charge transfer total cross section for Bi4+(6s) + Bi4+(6s) collisions (reaction 1), whereas single-electron capture into the singlet 6s6p states is the basic contributor to the total cross section in Bi4+(6s) + Bi4+(6p) collisions (reaction 2). In the collision energy interval mentioned above, the collision cross sections vary between 1.2 × 10?17 and 1.9 × 10?17 cm2 for reaction 1 and between 3.8 × 10?17 and 5.3 × 10?17 cm2 for reaction 2. In reaction 1, the 6s → 6p excitation cross sections vary from 0.6 × 10?16 to 0.8 × 10?16 cm2 for the singlet channel and from 2.2 × 10?16 to 2.8 × 10?16 cm2 for the triplet channel. The calculation results are compared with the data obtained in experiments with crossed ion beams of kiloelectronvolt energy. The fraction of metastable ions in the beams is estimated by comparing the experimental data with the weighted average theoretical results for the cross sections of reactions 1 and 2. From the data for the charge transfer cross sections, one can estimate particle losses in relativistic beams due to a change in the charge state of the ions colliding with each other in the beam because of betatron oscillations. 相似文献
8.
Shramana Mishra Budhi Singh Sayantan Bhattacharya J. K. Panda D. Kabiraj Anushree Roy Subhasis Ghosh 《Journal of Raman spectroscopy : JRS》2016,47(8):963-970
Raman spectroscopy and Hall measurements have been carried out to investigate the differences in near‐surface charge carrier modulation in high energy (~100 MeV) silicon ion (Si8+) and oxygen ion (O7+) irradiated n‐GaAs. In the case of O ion irradiation, the observed decrease in carrier concentration with increase in ion fluence could be explained in the view of charge compensation by possible point defect trap centers, which can form because of elastic collisions of high energy ions with the target nuclei. In Si irradiated n‐GaAs one would expect the carrier compensation to occur at a fluence of 2.5 × 1013 ions/cm2, if the same mechanism of acceptor state formation, as in case of O irradiation, is considered. However, we observe the charge compensation in this system at a fluence of 5 × 1012 ions/cm2. We discuss the role of the complex defect states, which are formed because of the interaction of the primary point defects, in determining carrier concentration in a Si irradiated n‐GaAs wafer. The above results are combined with the reported data from the literature for high energy silver ion irradiated n‐GaAs, in order to illustrate the effect of both electronic and nuclear energy loss on trap creation and charge compensation. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
9.
Precision optical spectroscopy of radioactive Be isotopes produced in projectile fragmentation has been performed for the first time at the prototype SLOWRI facility of RIKEN RI-Beam Factory. The ground state hyperfine constants of 7Be+ and 11Be+ were determined with relative accuracies of 6 × 10?7 and 3 × 10?8, respectively, by laser-microwave double resonance spectroscopy of laser-cooled ions in a trap. The optical transition energies from the ground S-state to the excited P-state of Be isotope ions were also measured to determine the nuclear charge radii from the isotope shifts. Development of the universal slow RI-beam facility??SLOWRI??based on the rf-carpet ion guide technique is progressing at RIKEN RI-beam factory. An additional capability of providing parasitic slow RI-beams from the projectile fragment separator BigRIPS is also discussed. 相似文献
10.
TiO2 thin film synthesized by the RF sputtering method has been implanted by 120 keV Ag? ion with different doses (3?×?1014, 1?×?1015, 3?×?1015, 1?×?1016 and 3?×?1016 ions/cm2). Further, these were characterized by Rutherford back Scattering, XRD, X-ray photoelectron spectroscopy (XPS), UV–visible and fluorescence spectroscopy. Here we reported that after implantation, localized surface Plasmon resonance has been observed for the fluence 3?×?1016 ions/cm2, which was due to the formation of silver nanoparticles. Ag is in metallic form in the matrix of TiO2, which is very interestingly as oxidation of Ag was reported after implantation. Also, we have observed the interaction between nanoparticles of Ag and TiO2, which results in an increasing intensity in lower charge states (Ti3+) of Ti. This interaction is supported by XPS and fluorescence spectroscopy, which can help improve photo catalysis and antibacterial properties. 相似文献
11.
M.S. Attia A.O. Youssef Amr A. Essawy M.S.A. Abdel-Mottaleb 《Journal of luminescence》2012,132(10):2741-2746
Highly luminescent complexes of Eu and Tb ions with norfloxacin (NFLX) and gatifloxacin (GFLX) were prepared in sol–gel matrix. The red and green emissions of Eu and Tb ions were obtained by the energy transfer from the triplet state of (NFLX) and (GFLX) to the excited emitting states (5D0 and 5D4) of Eu and Tb, respectively. The intensity of the electric field emission bands (5D0→7F2, 617 nm and 5D4→7F5, 545 nm) of Eu and Tb ions were proportional to the concentration of (NFLX at pH 6.0) and (GFLX at pH 3.5) in acetonitrile with excitation wavelengths (λex) (340 and 395) and (370 and 350 nm) for Eu and Tb ions, respectively. The monitored luminescence intensity of the system showed a good linear relationship with the concentration of NFLX within a range of 5×10?9–5.8×10?6 and 5×10?8–1.0×10?6 mol L?1 with a correlation coefficient of 0.990, and for GFLX within a range of 2.4×10?9–3.2×10?5 and 5×10?8–8.0×10?6 mol L?1 with a correlation coefficient of 0.995. The detection limit (LOD) was determined as 3.0×10?9 and 1.0×10?8 mol L?1 for NFLX and 1.6×10?10 and 2.0×10?8mol L?1 for GFLX. The limit of quantification (LOQ) is 9×10?9 and 3.0×10?8 and 4.8×10?10 and 6.0×10?8 in case of Eu and Tb, respectively. 相似文献
12.
High brightness amine‐terminated silicon nanocrystals (Si NCs) have been utilized in a simple and rapid assay for the highly selective and sensitive detection of Fe3+ via quenching of their strong blue luminescence, without the need for analyte‐specific labeling groups. Sensitive detection of Fe3+ is successfully demonstrated, with a linear relationship observed between luminescence quenching and Fe3+ concentration from 5 × 10?6 to 900 × 10?6m and a limit of detection of 1.3 × 10?6m . The Si NCs show excellent selectivity toward Fe3+ ions, with no quenching of the luminescence signal induced by the presence of Fe2+ ions, allowing for solution phase discrimination between the ionic species in different charge states. 相似文献
13.
S. R. Majid N. H. Idris M. F. Hassan T. Winie A. S. A. Khiar A. K. Arof 《Ionics》2005,11(5-6):451-455
The room temperature conductivity of the chitosan complex containing 40 wt.% of salt increased from 6.02×10−6 Scm−1 to 2.10×10−5 Scm−1 after the addition of 1.0 wt.% aluminosilicate. Conductivity of the electrolyte is contributed from the charge carrier density
and ionic mobility. The Rice and Roth model was applied in calculating the mobility, μ and density of ions, n. The number
density of ions, n, increases with temperature, while mobility, μ decreases with increasing temperature. This work also suggests
that the filler did not change the conduction mechanism of the charge carrier in chitosan-salt-filler complexes but helped
to increase the conductivity value of the materials.
Paper presented at the International Conference on Functional Materials and Devices 2005, Kuala Lumpur, Malaysia, June 6 –
8, 2005. 相似文献
14.
The scattering of He+, Ne+ and Ar+ ions from Rh {111} is measured as a function of the azimuthal angle of the primary ion for an incident polar angle of 70° from the surface normal and an inplane collection angle of 60°. In this case anisotropy is defined as the ratio of the yield of ions scattered having the azimuth of 〈110〉 to the yield of those having the azimuth of 〈211〉. The yield ratio for all particle types correlates with particle velocity. The ratio is ~ 1 at low velocities, decreases to ~ 0.2 at 8 × 106 and then increases to a value of 1.4 at 25 × 106. Molecular dynamics calculations have been performed for Ne+ ion scattering from Rh{111} in order to understand the changes in anisotropy with particle velocity. Qualitative agreement with the experimental results is obtained without having to account for neutralization. A neutralization probability that depends on the collision time improves the agreement between the calculated and experimental yield ratios. A velocity dependent probability will not affect the ratio of yields in two different azimuthal directions. 相似文献
15.
G. S. Sarkisov V. Yu. Bychenkov V. T. Tikhonchuk A. Maksimchuk S. Y. Chen R. Wagner G. Mourou D. Umstadter 《JETP Letters》1997,66(12):828-834
We report the first interferometric observations of the dynamics of electron-ion cavitation of relativistically self-focused
intense 4 TW, 400 fs laser pulse in a He gas jet. The electron density in a channel 1 mm long and 30 μm in diameter drops
by a factor of approximately 10 from the maximum value of ∼8×1019 cm−3. A high radial velocity of the plasma expansion, ∼3.8×108 cm/s, corresponding to an ion energy of about 300 keV, is observed. The total energy of fast ions is estimated to be 6% of
the laser pulse energy. The high-velocity radial plasma expulsion is explained by a charge separation due to the strong ponderomotive
force. This experiment demonstrates a new possibility for direct transmission of a significant portion of the energy of a
laser pulse to ions.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 12, 787–792 (25 December 1997)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
16.
D. Hasselkamp E. Mondry A. Scharmann 《Zeitschrift für Physik A Hadrons and Nuclei》1979,289(2):151-155
An experiment is reported in which the second order Doppler-shift has been determined by the observation of theHα-line emitted by linearly moving hydrogen atoms of velocities 2.53×108 cm/s?9.28×108 cm/s. In contrast to previous experiments the direct transversal observation has been used for the first time. The coefficient of the second order term in the relativistic approximation is found to be 0.52±0.03 which compares good with the theoretical value of 1/2. 相似文献
17.
A single crystal of sapphire was implanted with 100-keV57Fe to a dose of 3.4×1015 ions/cm2. The charge states of iron ions were investigated with the CEMS technique at low temperatures. The formation of the observed
charge states Fe2+(1) and Fe2+(2) were elucidated in terms of crystal structure. 相似文献
18.
J. Hoffman W. Mróz A. Prokopiuk Z. Szymanski 《Applied Physics A: Materials Science & Processing》2008,92(4):921-926
The plasma plume induced during ArF laser ablation of a graphite target is studied. Velocities of the plasma expansion front
are determined by the optical time of flight method. Mass center velocities of the emitting atoms and ions are constant and
amount to 1.7×104 and 3.8×104 m s−1, respectively. Higher velocities of ions result probably from their acceleration in electrostatic field created by electron
emission prior to ion emission. The emission spectroscopy of the plasma plume is used to determine the electron densities
and temperatures at various distances from the target. The electron density is determined from the Stark broadening of the
Ca II and Ca I lines. It reaches a maximum of ∼9.5×1023 m−3 30 ns from the beginning of the laser pulse at the distance of 1.2 mm from the target and next decreases to ∼1.2×1022 m−3 at the distance of 7.6 mm from the target. The electron temperature is determined from the ratio of intensities of ionic
and atomic lines. Close to the target the electron temperature of ∼30 kK is found but it decreases quickly to 11.5 kK 4 mm
from the target. 相似文献
19.
M. F. Artamonov V. I. Krasov V. L. Paperny 《Journal of Experimental and Theoretical Physics》2001,93(6):1216-1221
The parameters of Cun+ and Tan+ ions from the plasma of a vacuum spark with a voltage up to 2.5 kV and a current rise rate up to 2 × 1010 A/s are studied using the time-of-flight method. At the initial stage of the discharge, bursts of beams of accelerated multiply charged ions from the cathode flame have been detected. It is established that the charge state distribution and energy of a beam are controlled by the initial voltage U 0 of the capacitor. Upon an increase in this voltage, the average charge of copper ions attains the value +9, and the average charge of tantalum ions can be as high as +20, while the energy attains values of 150 and 350 keV, respectively. It is found that the average energy of ions with charge Z increases in proportion to the charge and is close to the energy eZU 0 which would have been acquired by ions accelerated in the electric field of the discharge gap. 相似文献
20.
A zirconia film was implanted at room temperature with 100 keV57Fe+ to a fluence of 8×1016 ions/cm2. The analysis of the Conversion Electron Mössbauer spectra shows that iron is distributed among different charge states: Fe0 (in a form of small and large metallic iron aggregates) Fe2+ and Fe4+. The evolution of the iron depth profile deduced from Rutherford backscattering measurements as well as the change in the charge states of iron as a function of annealing under argon atmosphere are presented. 相似文献