JP3345256B2 - Charged particle detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle detector for measuring the energy spectrum of a charged particle by measuring the energy spectrum of the charged particle.

[0002]

2. Description of the Related Art In a charged particle detecting device such as an electron detecting device, charged particles are subjected to energy spectroscopy, the number of the particles is measured, and an energy spectrum as an intensity distribution with respect to the energy of the charged particles is measured. This charged particle detection device includes an energy spectroscopy unit and a particle detection unit. Conventionally, a slit and a photomultiplier tube for increasing the energy resolution have been used as a particle detector, but recently, a multi-channel plate (MCP) and a position-sensitive detector have been used as a particle detector. This method is considered to be a method in which a number of slits and photomultiplier tubes are arranged side by side, and can detect all particles emitted from the energy dispersing unit, so that the detection efficiency can be improved.

FIG. 8 is a schematic diagram showing a conventional electronic detecting device using a multi-channel plate and a position-sensitive detector. As shown in the drawing, the inner hemisphere 4 and the outer hemisphere 5 constitute a hemispherical electron spectrometer 9, an electrostatic lens 10 is provided at the entrance of the hemispherical electron spectrometer 9, and the hemispherical electron spectrometer 9 is provided.
A multi-channel plate 2 and a position-sensitive detector 3 are provided at the outlet of the device.

[0004] In this electron detecting device, by partially changing the electric field of the electrostatic lens 10, a blocking potential is applied to the entrance of the hemispherical electron spectrometer 9, and the blocking potential is set within a set range. , And the electrons are subjected to energy spectroscopy using an electrostatic field by a hemispherical electron spectrometer 9.
The energy spectrum of electrons is measured by the multi-channel plate 2 and the position-sensitive detector 3.

[0005] In such an electron detection device, since the stop potential is scanned, the energy spectrum can be measured to some extent accurately.

[0006]

However, in the conventional electron detecting device, since the blocking potential is scanned, the measuring time is the time required for one step of scanning (gate time), and the scanning voltage is one time per scanning. Is determined by the number of data points constituting the energy spectrum and the energy range of the energy spectrum, the measurement time is inevitably increased to several seconds to several tens of seconds.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a charged particle detection device capable of accurately measuring an energy spectrum and having a short measurement time.

[0008]

In order to achieve this object, the present invention provides a charged particle detector having a spectroscope for performing energy spectroscopy of charged particles using an electrostatic field, a multi-channel plate, and a position sensitive detector. At
An electric field correction electrode having an opening is provided on the front surface of the multi-channel plate, and a linear conductor parallel to a direction in which energy dispersion occurs is provided in the opening.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view showing a part of an electron detection device according to the present invention, and FIG. 2 is a diagram showing a part of the electron detection device shown in FIG. As shown in the figure, an electric field correction electrode 1 having an opening 6 in front of a multi-channel plate 2
The opening 6 is provided with a gold wire 7 parallel to the direction in which the energy spectrum occurs, that is, the radial direction of the inner hemisphere 4 and the outer hemisphere 5.

In the electron detecting device shown in FIGS. 1 and 2, the gold wire 7 corrects the electric field, so that the scanning can be performed at the position calculated from the electric field of the hemispherical electron spectrometer 9 without scanning the stopping potential. Since electrons can be detected, the energy spectrum can be measured accurately, and the measurement time can be shortened to, for example, several hundred milliseconds or less. Therefore, a dynamic system can be measured in a time-resolved manner.

FIG. 3 is a graph showing the measurement results obtained by the electron detection device shown in FIGS. That is, the silver plate is irradiated with Kα characteristic X-rays (1486.6 eV) of aluminum, and the energy of electrons passing through the centers of the inner hemisphere 4 and the outer hemisphere 5 is set to be 33.37 eV.
With the potential applied to the outer hemisphere 5 and the setting of the electrostatic lens 10 fixed, the binding energy is 1321.6 to 131.
It is a graph which shows the result of having detected the range of 8.4 eV.
As is clear from this graph, the energy spectrum has no energy dependence, and an energy spectrum having almost the same intensity is obtained as a whole, indicating that the original energy spectrum can be almost reproduced. Note that the tendency of the graph does not change even if the energy of the electrons detected by the multi-channel plate 2 decreases.

FIG. 5 is a graph showing the measurement results when the electrode shown in FIG. 4, that is, the electrode 1a without the wire is provided in the opening 6, instead of the electric field correction electrode 1 of the electron detection device shown in FIG. . The measurement conditions are the same as in FIG. As is clear from this graph, the width of the energy spectrum is narrower than the case shown in FIG. 3, and there are portions where the photoelectron intensity is large on both sides. This reflects that the aperture 6 itself serves as a lens, preventing electrons from coming to a portion near the aperture 6, and that the electric field is distorted. Therefore, the energy spectrum can be measured more accurately by using the electric field correction electrode 1 than by using the electrode 1a. When the energy of the electrons detected by the multi-channel plate 2 decreases, the region where the photoelectron intensity is large is reduced.

FIG. 7 shows a gold wire 1 parallel to the electrode shown in FIG. 6, that is, the opening 6, which is parallel to the direction in which the energy spectrum occurs, instead of the electric field correction electrode 1 of the electron detector shown in FIG.
7 is a graph showing measurement results when an electrode 1b having a gold wire 12 parallel to a direction perpendicular to a direction 1 and a direction in which energy spectroscopy occurs is provided. The measurement conditions are the same as in FIG. As is clear from this graph, the envelope shows the same tendency as in FIG. 3, but a sawtooth wave is formed. The number of the waves is the same as the number of the gold wire 12, which indicates that the gold wire 12 generates a small electric field gradient and the electric field is locally distorted. Therefore, the energy spectrum can be measured more accurately using the electric field correction electrode 1 than using the electrode 1b. When the energy of the electrons detected by the multi-channel plate 2 decreases, the amplitude of the sawtooth wave increases.

In the above embodiment, the electron detection device for detecting electrons has been described. However, it is apparent that the present invention can be applied to a charged particle detection device for detecting other charged particles such as ions. Further, in the above embodiment, the hemispherical electron spectrometer 9 is used as the spectroscope, but a parallel plate type spectrometer, a cylindrical type spectrometer, or the like can be used. In the above-described embodiment, the gold wire 7 is used as the linear conductor, but a wire made of a conductive material other than gold may be used. In the above-described embodiment, the gold wire 7 is used as the linear conductor. However, a linear conductor may be formed by providing a slit in a conductive plate.

[0015]

As described above, in the charged particle detecting device according to the present invention, since the linear conductor corrects the electric field, the charged particle can be detected at an appropriate position without scanning the stopping potential. Therefore, the energy spectrum can be measured accurately, and the measurement time can be shortened.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a part of an electron detection device according to the present invention.

FIG. 2 is a diagram showing a part of the electronic detection device shown in FIG.

FIG. 3 is a graph showing measurement results obtained by the electron detection device shown in FIGS. 1 and 2;

FIG. 4 is a diagram showing electrodes.

5 is a graph showing measurement results obtained by an electron detection device having the electrodes shown in FIG.

FIG. 6 is a diagram showing another electrode.

FIG. 7 is a graph showing measurement results obtained by an electron detection device having the electrodes shown in FIG.

FIG. 8 is a schematic diagram showing a conventional electron detection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electric field correction electrode 2 ... Multi-channel plate 3 ... Position sensitive type detector 6 ... Aperture 7 ... Gold wire 9 ... Hemispherical electron spectrometer

──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Masami Taguchi 2500 Hagizono, Chigasaki-shi, Kanagawa Prefecture Inside Albuque Phi Corporation (72) Inventor Yoshiteru Kida 2500 Hagizono, Chigasaki-shi, Kanagawa Pref. (56) References JP-A-4-341746 (JP, A) JP-A-59-189548 (JP, A) JP-A-1-175159 (JP, A) Japanese Utility Model Laid-Open No. 61-74951 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01J 49/48

Claims (1)

(57) [Claims] 1. A charged particle detection apparatus having a spectroscope for energy spectroscopy of charged particles using an electrostatic field, a multi-channel plate, and a position-sensitive detector, an electric field correction electrode having an opening in front of the multi-channel plate. And a linear conductor parallel to a direction in which energy splitting occurs is provided in the opening.