JPS62234860A - Multi-slit type mass spectrometer - Google Patents

Abstract

PURPOSE:To miniaturize a detector together with its original device by leading the light emitted from an electron-light coversion face to a one-dimensional light detector via an optical fiber'. CONSTITUTION:Those ions passing through a multi-slit plate 3 are incident on a multi-channel plate 4 located further behind therefrom, and converted to secondary electrons before being amplified. A phosphor film 5a is applied to the upper face of a fixed plate 5 located further behind the plate 4. And the secondary electrons emitted from the plate 4 are incident on the phosphor film 5a to be converted to the light. the euds on one side of many streaks of optical fiber 6 are disposed at the interval of slits on the lower face of the phosphor film 5a and the ends on the other side of the fibers 6 are formed together in an optical plate 7. And, since the width of a linear sensor 9 acting as a one-dimensional detector is smaller than the width of the plate 7, any shrunk image is further reduced in its size by using a lens 8 to be formed in an image on the detecting surface of the sensor 9. Thus, the detector can be minaturized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multi-slit type analysis device in which a multi-slit plate having a plurality of slits is arranged on the ion focusing and development surface by a magnetic field. .

[Prior Art] An example of a multi-slit mass spectrometer is described in, for example, Japanese Patent Laid-Open No. 57-23457.

This mass spectrometer analyzer uses a magnetic field to converge and deploy sample ions on a focusing surface according to the quality ffi charge ratio, and a large number of micro ion detectors arranged along the ion deployment direction behind the focusing surface. and a multi-slit plate having a plurality of slits arranged on the convergence surface between the magnetic field and the ion detector array and arranged in the ion deployment direction. The ion detector is composed of a channel plate and a group of micro collector electrodes arranged behind the channel plate.

[J? [Problems that Akira is trying to solve] However, in such a multi-slit mass spectrometer, a microscopic collector electrode must be arranged to cover the entire width of the channel plate, which increases the size of the detector. was unavoidable. Furthermore, the detector must be housed in a vacuum chamber, which inevitably increases the size of the entire device.

The present invention has been made in view of this point, and it is an object of the present invention to provide a multi-slit mass spectrometer that allows the detector to be made smaller and the device to be made smaller as well.

[Means for Solving the Problem] In order to achieve this objective, the multi-slit mass spectrometer according to the present invention uses a magnetic field to converge and expand sample ions onto a convergence surface according to the mass h1 charge ratio. a multi-slit plate having a plurality of slits arranged along the convergence plane and arranged in the direction of ion expansion on the convergence plane; A multi-channel plate on which ions are incident on different positions; an electron-light conversion surface disposed on the output side of the channel plate on which secondary electrons from the channel plate are incident on different positions; and the electron-light conversion surface. and a one-dimensional photodetector for detecting the light generated by the electron-light conversion surface, and the light from the electron-light conversion surface is guided to the one-dimensional photodetector via the first lateral fiber. It is said that

Hereinafter, one embodiment of the present invention will be explained in detail using the drawings.

[Example] The drawing is a schematic diagram of a multi-slit mass spectrometer showing an example of the present invention. In the figure, 1 is a uniform magnetic field that constitutes the quality m analysis system, and the incident sample ions 2 are dispersed in this magnetic field according to the mass-to-charge ratio, are emitted in parallel from the la field, and then are developed as a spectrum on the convergent plane. be done. A multi-slit plate 3 is arranged on this converging surface.

, the above multi-slit plate 3 contains inorganic elements L1 to U299.
A large number of slits are provided at positions corresponding to the mass numbers so that ions in the range of can be detected. For example, the distance Qi from the point of incidence P of ions into the magnetic field to the slit of mass number mi is Q i -k 8 "G-
It is set. Therefore, if the interval between the slits is Δ2, Δinc is expressed as Δinc−k(r]−F plane bottom). Although the width of the slit may be variable, it may be set to about 100 μm in order to obtain a resolution of about 1000.

The ions that have passed through this multi-slit plate 3 are incident on a multi-channel plate 4 located further behind, where they are converted into secondary electrons and amplified.

Reference numeral 5 denotes a fixed plate placed further behind the multi-channel plate, the upper surface of which is coated with fluorescent light 115a.
Secondary electrons emitted from the multichannel plate 4 enter this fluorescent film and are converted into light. Note that in order to increase sensitivity, a voltage is applied to this fluorescent film to accelerate secondary electrons. Further, on the lower surface of the fluorescent film 5a, one end of a large number of optical fibers 6 is arranged with a slit interval Δ2, and is fixed by a fixing plate 5.

If the size of the ion beam that has passed through the slit is, for example, height 211 x width Q, 3mo+, and the fluorescent film 5a into which this ion beam enters also produces a light emitting spot of approximately the same size, the cross-sectional size of the optical fiber 6 will also be the same. They are set approximately equal. The other ends of the optical fibers, one end of which is disposed on the lower surface of the fluorescent film 5a at a distance of Δ, are arranged in an orderly manner without gaps and are fused to form the optical plate 7. This optical plate 7 also serves as a partition plate for keeping the magnetic field 1 side in a vacuum.

Therefore, from the bottom surface of the optical plate 7 to the atmosphere,
A reduced image of the spectrum developed over the entire surface of the fluorescence IEi5a can be taken out. Reference numeral 9 denotes an optical linear sensor for detecting this reduced image, which is a one-dimensional detector in which minute light detection elements are arranged in a line. The reduced image can be detected even if this linear sensor is applied directly to the lower surface of the plate 7, but in this embodiment, since the width of the linear sensor is smaller than the width of the plate 7, the reduced image is detected using the lens 8. The image is further reduced in size and formed on the detection surface of the linear sensor 9. Examples of this linear sensor include EG&
It is possible to use a product sold by G RETICON under the trade name RETICON.

In the above-described configuration, the ions are developed as a spectrum on the converging surface according to the mass ratio, and the ions taken out through the multi-slit are multiplied by the multi-channel plate 4, and then converted into light by the fluorescent film 5a. converted. Therefore, a spectrum image is formed on the fluorescent light ll5a, and this spectrum is transmitted through the optical fiber 6.
is guided to the lower surface of the optical plate 7 as a reduced image, and detected by the linear sensor 9.

In the above embodiment, the ion beam passing through the multi-slit plate 3 spreads somewhat before reaching the multi-channel plate 4, but in terms of resolution, it is already separated from the nine adjacent ion beams by the slit. This won't hurt you.

Furthermore, in order to prevent adjacent optical fibers from interfering with each other in the optical plate 7, it is preferable to arrange a black stripe between them to separate them.

Also, instead of the lens 8, an optical fiber is used,
Moreover, these optical fibers may be divided into a plurality of channels and made to enter a plurality of linear sensors provided corresponding to each channel.

[Effects of the Invention] As detailed above, in the present invention, ions grMed as a spectrum on a converging surface are amplified by a multichannel plate, and then converted into light by an electron-light conversion means, and the obtained spectrum is Since the fiber is reduced by an optical fiber and guided to the near sensor, it is possible to downsize the detector.

Furthermore, since the detector can be placed outside the vacuum, it is also possible to downsize the device.

[Brief explanation of drawings]

The accompanying drawing is a schematic diagram showing an example of a multi-slit mass spectrometer according to the present invention. 1 Uniform magnetic field 3: Multi-slit plate 4: Multi-channel plate 5: Fixed plate 6: Optical fiber 7: Optical plate

Claims (1)

[Claims] a multi-slit plate having a magnetic field for focusing and developing sample ions on a focusing surface according to their mass-to-charge ratio, and a plurality of slits arranged along the focusing surface and arranged in the direction of ion development on the focusing surface; , a multi-channel plate placed behind the multi-slit plate, through which ions passing through the multi-slit plate are incident on different positions; and a multi-channel plate placed on the output side of the channel plate, through which secondary electrons from the channel plate are placed. It is equipped with an electron-light conversion surface incident on different positions and a one-dimensional photodetector for detecting the light generated on the electron-light conversion surface, and the light from the electron-light conversion surface is transmitted through an optical fiber. 1. A multi-slit mass spectrometer, characterized in that the light is guided to the one-dimensional photodetector through the one-dimensional photodetector.