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1.
Alexander Herlert Christopher Borgmann Daniel Fink Christian Holm Christensen Magdalena Kowalska Sarah Naimi 《Hyperfine Interactions》2011,199(1-3):211-220
The influence of space charge on the mass selection of ions stored in a Penning trap was investigated with the ISOLTRAP experiment at CERN/ISOLDE. A mixture of 85,87Rb?+? ions has been used to probe the change of the experimental parameters, e.g. frequencies and amplitudes of the radiofrequency excitations, as a function of the number of ions present in the trap. 相似文献
2.
《Journal of Electrostatics》2005,63(6-10):649-656
In this paper, three kinds of annealing methods with different cooling rates are used to prepare low-density polyethylene (LDPE) samples with different microstructure in crystallinity. The effects of crystallinity on space charge properties are investigated. It was found that homo-charges are easier to accumulate in high rate cooling sample and hetero-charges are easier to accumulate near cathode in low rate cooling sample. It was also found that charge movement and neutralization occurs with the increases of the applied field and the voltage applying duration. Based on these results, the influence of crystallinity on space charge accumulation is emphasized. 相似文献
3.
Absorption current and photo- and thermally stimulated depolarization measurements on Melinex PET at high fields are summarised. They provide clear evidence of field and temperature dependent injection from Al and In cathodes leading to the formation of stored space charge. Electron beam-induced depolarization experiments confirm significant injection of electrons from an Al cathode, and determine their range as ?1μm at room temperature and 1MV/cm. A small hole charge is found in the vicinity of an Al anode. Au contacts appear to inject only holes. The results confirm the conclusion drawn by previous authors that any quasi-steady conduction observed in Melinex PET is likely to be contact-induced. 相似文献
4.
An analysis is made of mechanisms of the formation and redistribution of space charge which influence the dielectric hysteresis
in SrTiO3. The excess space charge density in SrTiO3 at 4.2 K is estimated by comparing calculated and experimental dependences of the initial capacitance and the dielectric
hysteresis parameter ΔC/C
0 as a function of the crystal thickness.
Fiz. Tverd. Tela (St. Petersburg) 40, 245–247 (February 1998) 相似文献
5.
首次研究了磁绝缘线振荡器中射频场(包括辐射波场和空间电荷波场)对空间电荷的调制,得到了在饱和时谐波电流一阶分量的公式。这个公式表明:考虑空间电荷波时,在小信号和辐射波与空间电荷波同相的条件下,它将增强谐波电流。在大信号时,情况不确定;谐波电流一阶分量将随二极管上电压的增加而增加,随运行频率和饱和长度的增加而减少。 相似文献
6.
首次研究了磁绝缘线振荡器中射频场(包括辐射波场和空间电荷波场)对空间电荷的调制,得到了在饱和时谐波电流一阶分量的公式。这个公式表明:考虑空间电荷波时,在小信号和辐射波与空间电荷波同相的条件下,它将增强谐波电流。在大信号时,情况不确定;谐波电流一阶分量将随二极管上电压的增加而增加,随运行频率和饱和长度的增加而减少。 相似文献
7.
Han S. Uhm Joon Y. Choe Chung M. Kim 《International Journal of Infrared and Millimeter Waves》1983,4(3):361-374
Stability properties of the free streaming mode in an electron beam propagating through a cylindrical waveguide loaded with a tape helix are investigated, including influence of high space harmonic perturbations. Closed algebraic dispersion relation of the free streaming mode are obtained. Properties of the high space harmonic perturbations are numerically investigated in connection with application on a high frequency microwave amplifier. One of the most important features in this analysis is that instability of high harmonic perturbations occurs at a very large value of microwave frequency. In this regard, millimeter microwave can be easily attainable by reducing the helix radius to a subcentimeter. 相似文献
8.
《Journal of Electrostatics》2014,72(6):457-461
At present, there is no appropriate measurement techniques for space charge. In this paper, a U-shaped cavity device is developed as the space charge measurement device, which can be applied to transmission lines. Its design principle and calculation techniques of design parameter are also introduced. To test the space charge measurement accuracy of the U-shaped cavity device, a space charge generator is developed specifically for this experiment. The test results are excellent and show that the U-shaped cavity device can meet the design requirements. This technique is suitable for space charge measurement under transmission line normally charged work condition. 相似文献
9.
J.Frederick Koch 《Surface science》1976,58(1):104-127
Spectroscopic studies of the semiconductor surface space charge layer system complement and enlarge on the information derived from dc transport experiments. The paper fkst gives an account of far-infrared cyclotron resonance and dynamical conductivity studies in the surface layer. Such work explores the carrier motion in the plane of the space charge layer. A later section discusses intersubband spectroscopy, experiments in which the quantized motion in bound levels normal to the surface is probed. 相似文献
10.
11.
Gartstein YN Ramesh PS 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》1999,60(1):1069-1072
In kinetic simulations of a flow of charged particles between two parallel plate electrodes, it is found that chaotic responses in space charge limited currents can be induced by a periodically varying applied voltage. 相似文献
12.
M.P. Petrov V.V. Bryksin S. Wevering E. Krätzig 《Applied physics. B, Lasers and optics》2001,73(7):699-703
For the first time the effects of overall doubling, spatial doubling, and overall rectification of space charge waves in a
photorefractive crystal (Bi12GeO20, BGO) have been detected and theoretically studied. The effects of overall doubling and overall rectification resemble second-harmonic
generation and rectification of light in nonlinear optics. A good agreement between theory and experiment is found for the
effect of spatial doubling, while for overall doubling and overall rectification effects only a qualitative agreement between
theory and experiment has been established until now.
Received: 13 July 2001 / Published online: 10 October 2001 相似文献
13.
14.
The macroscopic quantum entanglement in capacitively
coupled SQUID (superconducting quantum interference device)-based
charge qubits is
investigated theoretically. The entanglement characteristic is discussed by
employing the quantum Rabi oscillations and the concurrence. An
interesting conclusion is obtained, i.e., the magnetic fluxes
Фx1 and Фx2 through the superconducting
loops can adjust the entanglement degree between the qubits. 相似文献
15.
Macroscopic space charge field in disturbed quasineutral plasma 总被引:1,自引:0,他引:1
16.
M.E. Van Hulle 《Surface science》1975,52(3):513-520
An analysis is made of the surface space charge layer in thin silver halides. The proposed model takes into account that the surface sites have a binding energy different from the normal lattice sites. A well defined number of surface sites is introduced in the thin film space charge potential calculations. Numerical computations have been performed for pure films and films doped with divalent ions which are homogeneous distributed on normal lattice sites. 相似文献
17.
The betatron matching of a rotationally asymmetric beam in space charge dominated low-energy beam transports (LEBTs) where solenoids are used for the transverse matching has been studied.For better understanding, the coupling elements of a beam matrix are interpreted in special forms that are products of a term defined by the Larmor rotation angle and another by the difference between the beam matrix elements in the two transverse planes.The coupling form originally derived from the rotationally symmetric field in solenoids still holds when taking into account the rotationally asymmetric space charge forces that are due to the unequal emittance in the two transverse planes.It is shown in this paper that when an LEBT mainly comprising solenoids transports a beam having unequal emittance in the two transverse planes and the linear space charge force is taken into account, the initial Twiss parameters can be modified to obtain the minimum and equal emittance at the LEBT exit.The TRACE3D calculations also prove the principle.However, when quadrupoles that are also rotationally asymmetric are involved in between solenoids, the coupling between the two transverse planes becomes more complicated and the emittance increase is usually unavoidable.A matching example using the CSNS (China Spallation Neutron Source) LEBT conditions is also presented. 相似文献
18.
A method of calculation of the electric field intensity in a quasineutral plasma homogeneity of which is disturbed is found for the case when the problem can be formulated as one-dimensional. The general formula (19) comprising the Ohm's law, ambipolar approximation and higher approximations of the space charge electric field intensity, expressed in terms of deviationn
+ in ion density and its derivatives, is found and the values of the errors of these approximations are derived. Numerical calculations for the sinusoidal as well as for the Gaussian form of the perturbation in the ion concentration are carried out. 相似文献
19.
The betatron matching of a rotationally asymmetric beam in space charge dominated low-energy beam transports (LEBTs) where solenoids are used for the transverse matching has been studied. For better understanding, the coupling elements of a beam matrix are interpreted in special forms that are products of a term defined by the Larmor rotation angle and another by the difference between the beam matrix elements in the two transverse planes. The coupling form originally derived from the rotationally symmetric field in solenoids still holds when taking into account the rotationally asymmetric space charge forces that are due to the unequal emittance in the two transverse planes. It is shown in this paper that when an LEBT mainly comprising solenoids transports a beam having unequal emittance in the two transverse planes and the linear space charge force is taken into account, the initial Twiss parameters can be modified to obtain the minimum and equal emittance at the LEBT exit. The TRACE3D calculations also prove the principle. However, when quadrupoles that are also rotationally asymmetric are involved in between solenoids, the coupling between the two transverse planes becomes more complicated and the emittance increase is usually unavoidable. A matching example using the CSNS (China Spallation Neutron Source) LEBT conditions is also presented. 相似文献
20.
The temperature dependence of the electrical conductivity of a charge-ordered crystal is studied with electron-phonon scattering processes taken into account. It is shown that the transition of the electronic subsystem of the crystal into the charge-ordered state results in an anomalous temperature dependence of the conductivity.DeceasedTranslated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 78–82, April, 1988. 相似文献