JPS5853147A - Charged-particle mass energy analyzer - Google Patents

Abstract

PURPOSE:To increase the resolution of a charged-particle mass energy analyzer, and simplify the designing and the manufacturing of the analyzer by making a deflection angle of 180 degrees to be achieved with a magnetic field, and performing mass discriminations by making ions to pass through the area of an electric field after they are deflected with the magnetic field. CONSTITUTION:The space between magnetic poles is narrowed by installing an electrode plate outside magnetic plates 3, so that the magnet is made smaller and the magnetic-field disturbance area is reduced. In addition, by making a magnetic-field deflection angle as large as 180 degrees, the influence of field disturbances, which develop at the ends of the magnetic poles, upon the particle- beam orbit can be reduced. As for the synergistic effect of the fringe fields of the electric field and the magnetic field, the influence of the superposed fringe field upon the ion orbit is reduced by separating the areas of the electric field and the magnetic field by decreasing the space between the magnetic poles. Besides, since the electric and the magetic fields are separated, assembly of the analyzer is facilitated, and a degree of freedom can be given to the deflection method which is carried out with the electric field.

Description

[Detailed description of the invention] The present invention relates to a charged particle mass energy analyzer.

#Analysis of the mass and energy of storm particles 1Usually, an electric field,
When particles are injected into a1, the rate of uneven thickness is /Ji
Different things are done using t- depending on Lt and energy.

The #I1 diagram, the JI2 diagram, and the JIa diagram are examples of conventionally used dividers that have been proposed.

In FIGS. 1 and 2, the 180 degree deflection type analyzer C1 electromagnetic field is applied to the analyzer area C1-1J.

The figure typically shows the case where two types of particle beams, such as H+ and D+, having the same charge number and different mass numbers are incident. A deflection plate 2 housed in a vacuum container 1 provides weight resistance, and an electromagnet 3 generates a magnetic field. In the figure, the directions are the same. Furthermore, the same figure shows a Ja container in which the X-nitrogen container itself also serves as a yoke of 11a stone. The electromagnetic field exists in a region 4 defined by the area of the magnetic pole plate and the area of the m pole plate. H incident on this area
The mixed beam 5 of + and D+ is the difference in Ranu radius! A# Momentum is only analyzed in the direction perpendicular to the electromagnetic field, and due to the difference in deflection caused by electromagnetism, the analysis of through current is performed in the direction of the electromagnetic field.

Now, in such a configuration, since the JJIL amount discrimination is also to be performed between the other boards, the inevitable
It becomes necessary to take a large distance between B1m. Therefore, electromagnets are required to have a large magnetomotive force, and electromagnets are required to have a large magnetomotive force. In addition, by expanding the contact between the polar plates, reef plates such as fringe areas can be formed. ! Telephone number B at the department
The effect of field disturbance increases. This effect is large, and the IA proposed SC makes the analysis of charged particle trajectories am am and dramatically improves the design of the analyzer.

- 10,000, $I The example in Figure 3 is a method that is considered to be suitable for reducing the size of the magnet. That is, the aim is to reduce the size of the magnet by narrowing the magnetic field by taking it out from between the electric mV and the magnetic field, and by reducing the deflection angle of the beam due to the magnetic field. This method is, in principle, a superior method. That is, in addition to the above-mentioned effects, if a particle detector is placed at the focal point of the beam by utilizing the lens effect of the electromagnet, the momentum ml@ can also be improved. However, this method is not practical when considering actual design and manufacturing. The reason for this is that if the magnetic field changes discontinuously at the edge of the IIm plate, field disturbance will always exist near the edge if L<. On the other hand, the Iris 3wg method attempts to analyze using this highly disordered region, and it is extremely difficult to understand the behavior of charged particles in a focused manner. An attempt to raise the rudder by τ using the point (there are many circuits for this).

The present invention has been made in view of these points, and involves selecting an internal field angle of 180 degrees and performing 'X violet discrimination by passing through an electric field region after being deflected by the magnetic field. #
! Figure 4 shows its configuration. The figure shows an example of analysis of two types of beams, H+ and D+. This method can be said to be a combination of the methods shown in Figures 1 and 2, and the 3 worst methods.

In other words, by extending the electrode plate outside the magnetic plate, the gap between the magnetic poles is narrowed, thereby making the magnet smaller and reducing the field disturbance area. join and set the tiiJa deflection angle to 1
By setting the angle to be as large as 80 degrees, the influence of field disturbance at the magnetic pole tip on the particle beam trajectory can be reduced.

In addition, regarding the synergistic effect of the fringe fields of electric and magnetic fields,
Between magnetic poles I! By reducing s4 and making the electromagnetic field regions separate, the shadow # on the ion trajectory caused by the size of the fringe field as shown in Fig. 41.2 is reduced.

Although the above is an attempt to compensate for another drawback of FIG. 1.2.3, the advantages of each method are preserved even with this method. For example, in both figures j11 and 4, the magnetic field deflection angle is 1801[, and the magnetic field enters and exits the magnetic field perpendicularly. This is work, assembly...! IV Make it easy.

First, separating the electromagnetic fields can be summarized as 3. As shown in Figure 4, not only can the scallops be easily fogged, but also the degree of freedom can be added to the deflection method using an electric field. For example, like No. 411I.

By making the electron 1klIIL a suitable shape, it is possible to select the first distance of the particles in the direction of the electromagnetic field, and it is possible to arrange the particle detection ## on the -ii [edge, etc.

As mentioned above, in the present invention, by separating the electromagnetic field region and setting the magnetic field deflection angle to 180 degrees, it is possible to simplify the design and manufacture while taking advantage of the advantages of the value analysis method.

In the above-mentioned 'AIIIA example, there are two types of particles of class 1a, but they are not limited to class 2a1, and they meet in a wide range of moderate chains. In order to make the analyzer more compact, the electromagnet and the vacuum container were integrated into one, but in this case, the two were also separated.
It goes without saying that 4 can be used as a treatment form as shown in Figure g5.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the soil floor of the conventional method in which electromagnetic fields are superimposed, Figure @2 is the view facing @FiJ#, and Figure 3 is the method in which the a-field interior angle is made smaller and the electric a-field is separated by one. The vertical sectional view shown in FIG. 4 shows an embodiment of the present invention;
Figure 5 shows another embodiment of the present invention at a top cross section IillIg, which is a cross section of the bottom surface of FIG. l...smell 11! (Slips the electromagnetic yoke.) 2...
・Question - Facing plate, 3...Electromagnet #1 reef plate, 4...
Electric field chain acid, 5...#11Ea beam, 6...
・Collimator, 7...Emission point, 8...Particle detector, 9...Coil, 10...Value field area,
11...Vacuum container, ν...Electromagnet.

Claims (1)

[Claims] In systems where charged particles are introduced into an electromagnetic field and the mass and energy of the particles are analyzed by the deflection action of the electromagnetic field, after the particles are deflected 180 degrees by the magnetic field, an electric field that is in the same direction as the magnetic field or in the opposite direction. A charged particle mass energy analyzer that has the special feature of being able to analyze the 51L weight and energy of charged particles by allowing the 51L to elapse.