JPH02274193A - Monitoring device for microbeam image - Google Patents

Abstract

PURPOSE:To miniaturize a vacuum drum and to easily adjust a focal point by observing an image on a fluorescent plate by arranging a long range micro scope outside the vacuum drum in which the fluorescent plate irradiated with a microbeam is housed. CONSTITUTION:The long range microscope 9 is arranged outside the vacuum drum 6, and the image focused on the image on the fluorescent plate 2 via an observation window 8 provided at the vacuum drum 6 and observed by the long range microscope 9 is image-picked up by a television camera 4. In other words, the television camera 4 can be arranged outside the vacuum drum 6 together with the long range microscope 9 since the image on the fluorescent plate 2 in the vacuum drum 6 can be observed from the outside of the vacuum drum 6 by using the long range microscope 9. Therefore, the focal point can be adjusted without breaking the vacuum of the vacuum drum 6, and also, a miniaturized vacuum drum 6 can be used since it is not required to house a television camera system.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a microbeam image monitoring device.

(Prior Art) In a microbeam device that focuses an ion beam to a diameter on the order of several microns, the beam is focused while monitoring the beam image. Use a TV camera for that monitor.

The beam image thus photographed is viewed on a television monitor.

Figure 2 shows a conventional microbeam image monitor device, with 1
is a microbeam from a microbeam generator, which hits a fluorescent screen 2 and is converted into a light image.The image is photographed by a television camera 4 equipped with a close-up lens 3.

These are installed in a vacuum chamber 6, and a television camera 4
The video signal is sent via a line that passes through the hermetic seal 5 to a television monitor (CRT) outside the vacuum chamber 6.
7, where it is projected as a visible image.

(Problem to be Solved by the Invention) According to this configuration, since the television camera 4 equipped with the close-up lens 3 is installed in the vacuum chamber 6, its focus is adjusted to the fluorescent screen 2 before installation. It is necessary to keep it.

Once the vacuum chamber 6 is sealed and installed, the focus cannot be adjusted unless the vacuum chamber 6 is opened. Therefore, adjusting the focus was extremely troublesome.

Furthermore, as mentioned above, it is necessary to install the television camera 4 in the vacuum chamber 6, so the vacuum chamber 6 needs to be large enough to accommodate them, and a large one is inevitably used. There was an inconvenience that had to be done.

The object of the present invention is to facilitate the adjustment of the focus when monitoring a microbeam image on a television monitor, and to downsize the vacuum chamber.

(Means for Solving the Problems) This invention uses a long-distance microscope, which is installed outside a vacuum chamber in which a fluorescent screen is housed, and whose focus is directed onto the fluorescent screen through an observation window of the vacuum chamber. The image of the microbeam on the fluorescent screen is observed by capturing the image observed by the long-distance microscope with a television camera and projecting the image on a television monitor. Features.

(Function) By using a long-distance microscope, it becomes possible to view the image on the fluorescent screen inside the vacuum chamber from outside the vacuum chamber. This makes it possible to place a television camera and a long-range microscope outside the vacuum chamber.

This makes it possible to adjust the focus without breaking the vacuum in the vacuum chamber, and since the vacuum chamber does not need to house the television camera system, a smaller vacuum chamber can be used.

(Example) An embodiment of the invention will be explained with reference to FIG.

Note that parts given the same reference numerals as in FIG. 2 indicate the same or corresponding parts. According to this invention, a long-distance microscope @9
is used. In this case, the distance between the focal position and the objective lens is, for example, about 500III11.

A long-range microscope 9 is installed outside the vacuum chamber 6.

and through an observation window 8 provided in the vacuum chamber 6.

The image on the fluorescent screen 2 is focused.

As the fluorescent screen 2, for example, an inorganic crystal scintillator for radiation measurement, such as C5I (TQ), Zn
It is preferable to use S(Ag) or the like.

According to this, it has been commonly used.

It has better luminous efficiency than fluorescent screens made of crystal plates.

While the detection limit for a quartz plate was a beam current of about 50 pA, it has been confirmed that if an inorganic crystal scintillator is used as described above, it is possible to detect a beam current of 1 ρA or less.

The image observed by the long-distance microscope 9 is captured by the television camera 4. In this case, instead of directly capturing an image, the image intensifier 10 may be used to amplify the light intensity of the image taken by the long-distance microscope 9, and the image may be captured by the television camera 4.

When such an image intensifier 10 is used, the light sensitivity of the device system can be improved to approximately 30 μlux when the amplification degree is approximately 5.5×10′.

The image captured by the television camera 4 is displayed on a television monitor 7, where the image of the microbeam on the fluorescent screen 2 is observed. This is the same configuration as shown in FIG.

(Effects of the Invention) As detailed above, according to the present invention, a long-distance microscope is used, and this is installed outside a vacuum chamber that houses a fluorescent screen that is irradiated with a microbeam. 111! As a result, there is no need to install a TV camera system inside the vacuum chamber as in the past.
Therefore, it is possible to downsize the vacuum chamber, and the focus can be adjusted without breaking the vacuum of the vacuum chamber as in the past.

This has the effect of making the adjustment extremely easy.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional example. 1... Microbeam, 2... Fluorescent screen, 4... Television camera, 6... Vacuum chamber, 7... Television monitor,
8... Observation window, 9... Distance microscope,

Claims (1)

[Claims] A long-distance microscope is installed outside a vacuum chamber housing a fluorescent screen to which the microbeam is irradiated, and the focus of the long-distance microscope is set on the image on the fluorescent screen through an observation window of the vacuum chamber. A microbeam image monitoring device further comprising: a television camera for capturing an image on the fluorescent screen observed by the long-distance microscope; and a television monitor for displaying the image captured by the television camera.