ELECTROSTATIC LENS, AND PARALLEL BEAM GENERATION DEVICE AND PARALLEL BEAM CONVERGENCE DEVICE WHICH USE ELECTROSTATIC LENS AND COLLIMATOR
|Posted date||Mar 29, 2017|
|International application number||2016JP070744|
|International publication number||WO 2017010529|
|Date of international filing||Jul 13, 2016|
|Date of international publication||Jan 19, 2017|
|Title||ELECTROSTATIC LENS, AND PARALLEL BEAM GENERATION DEVICE AND PARALLEL BEAM CONVERGENCE DEVICE WHICH USE ELECTROSTATIC LENS AND COLLIMATOR|
|Abstract||Provided is a compact device which captures, over a wide solid angle range, electrically charged particles emitted from a point source and parallelizes the trajectories of said charged particles. The present invention is configured from: an electrostatic lens comprising a plurality of axisymmetric electrodes (10-14) and an axisymmetric aspherical mesh (2) which has a surface that is concave away from the point source; and a flat collimator plate (3) positioned coaxially with the electrostatic lens. The acceptance angle for the electrically charged particles generated from a point source (7) is ±30º or greater. The shape of the aspherical mesh (2), and the potentials and the positions of a ground electrode (10) and application electrodes (11-15) are adjusted so that the trajectories of the electrically charged particles are substantially parallelized by the electrostatic lens. The electrostatic lens and the flat collimator plate are positioned on a common axis so that after the trajectories of the electrically charged particles have been substantially parallelized with respect to the axis, the charged particles enter the flat collimator plate (3) at an angle of incidence substantially perpendicular thereto.|
|Outline of related art and contending technology||
A plurality of conventional concentric spherical grid of a combination of the phosphor screen of a blocking potential-type energy analyzer is, the low-speed electron beam diffraction observation and measurement of Auger electron spectroscopy is widely used. However, using the concentric spherical grid to be projected onto the spherical surface for the charged particles from, the plane of the microchannel plate cannot be used to amplify the signal a problem. In addition, the blocking potential-type energy analyzer is not, the action of a high-pass filter, signal-to-background ratio is poor, such as electron diffraction light 2 is not suited for three-dimensional angular distribution for the measurement was a problem. Thus, the axially symmetrical electrodes are used, three-dimensional angular distribution 2 the blocking potential-type energy analyzer projected onto a plane has been developed (Patent Document 1, reference 2) is, from the point source of charged particles generated by the acceptance angle is ±10° and was limited thereto. In addition, the blocking potential-type energy analyzer, an electron diffraction light becomes an obstacle when used to measure the fluorescence of the X line. X cannot be removed in the blocking potential lines, the higher the acceptance angle of the charged particles increases the amount of X-ray fluorescence, a problem occurs in the background.
On the other hand, in an electron spectrometer, an incident portion of the energy analyzer is often used for the electrostatic lens, the electrostatic lens, electrons emitted from the sample are captured as much as possible, and reduces the electron is incident from the analyzer, the energy resolution can be improved. An electron spectrometer is not limited to, solid-state properties such as biological analysis and the surface of the material in the basic research, the electron emitted from the crystal surface and the electron spectroscopy, electron diffraction, such as the emerging ion angular distribution is measured, how much of the open angle of the charged particles depends on the sensitivity or is taken, to increase the acceptance angle of the charged particles, can be measured over a wide solid angle range is demanded in the art. In addition, the acceptance angle of the charged particles is less than ±30 °, such as electron holography or electron diffraction light of the light is difficult to analyze the atomic arrangement structure, a solid angle of acceptance angle is equal to or greater than ±30° can be measured and the atomic arrangement analysis is achieved.
Conventional electrostatic lens, by the spherical aberration, a large opening angle of the beam focused to one point is difficult, the capture angle is limited to about ±20° was, by using the spherical mesh and thereby increase the sensitivity, the capture angle is improved to about ±30 ° (see Patent Document 3). In addition, non-spherical mesh of the negative spherical aberration by applying a corrective action, a plurality of electrodes to create an electric field to the optimum, a spherical mesh is wider than the capture angle of the spherical aberration correction electrostatic lens can be realized has been known (see Patent Document 4).
However, as shown in Fig. 21, disclosed in Patent Document 4 the spherical aberration correction electrostatic lens is 100, an enlarged virtual image having a negative spherical aberration is arranged so as to form, the sample plate 110 has a concave shape symmetrical with respect to the optical axis of the ellipsoidal surface and the non-spherical mesh 106 and, on the image plane side thereof and arranged coaxially to the optical axis, form a real image of the enlarged virtual image to produce a positive spherical aberration of a converging electric field in the plurality of electrodes (101-105) plane in a concentric configuration with, and the scale of the lens itself, the sample plate 110 to exit from the distance 107 (about L=0. 5m), the sample plate 110 and spherical aberration correction electrostatic lens 100 to store an entire magnetic shielding (not shown) ultra-high vacuum in the vacuum chamber has been increased. In addition, positive spherical aberration of the converged beam by the electric field results in a narrow solid angle of the beam and the point source, light emitted from the exit port 107 for, for example, the energy analysis of the projection for the case of the phosphor screen, electrons emitted from the exit 107 of the deflecting electric field (not shown) to prevent potential or analyzed, the phosphor screen (not shown) when the angle of the projection distribution, once, since it is necessary to converge to the exit slit, the size of the entire device is difficult.
|IPC(International Patent Classification)||
National States: AE AG AL AM AO AT AU AZ BA BB BG BH BN BR BW BY BZ CA CH CL CN CO CR CU CZ DE DK DM DO DZ EC EE EG ES FI GB GD GE GH GM GT HN HR HU ID IL IN IR IS JP KE KG KN KP KR KZ LA LC LK LR LS LU LY MA MD ME MG MK MN MW MX MY MZ NA NG NI NO NZ OM PA PE PG PH PL PT QA RO RS RU RW SA SC SD SE SG SK SL SM ST SV SY TH TJ TM TN TR TT TZ UA UG US UZ VC VN ZA ZM ZW
ARIPO: BW GH GM KE LR LS MW MZ NA RW SD SL SZ TZ UG ZM ZW
EAPO: AM AZ BY KG KZ RU TJ TM
EPO: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
OAPI: BF BJ CF CG CI CM GA GN GQ GW KM ML MR NE SN ST TD TG
Contact Information for " ELECTROSTATIC LENS, AND PARALLEL BEAM GENERATION DEVICE AND PARALLEL BEAM CONVERGENCE DEVICE WHICH USE ELECTROSTATIC LENS AND COLLIMATOR "
- Nara Institute Science and Technology Cooperative Research Division
- URL: http://www.naist.jp/sankan/index_en.html
- Address: 8916-5,Takayama-cho,Ikoma-shi,Nara , 630-0192
- Fax: 81-743-72-5194