JPS6353850A - Multi-channel analyzer for atom-like particle - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for analyzing the energy spectrum of neutral particles emitted from a plasma, and in particular for the analysis of the energy spectrum of neutral particles emitted from plasmas, in particular for the analysis of conducted energy spectra associated with, for example, controlled thermonuclear fusion. This invention relates to a multichannel analyzer for atomic particles, of the type used in research equipment.

BACKGROUND OF THE INVENTION Analysis of the energy spectrum of neutral atoms emitted by thermonuclear plasmas is the primary method for studying the A parameters of plasma ions.

A single channel atomic analyzer is known as a device for this purpose (V, V, Afroalmov, 1.
P.

Gladkovsky, Yu, S., Gordeyet.
et al., Zhurnal Technichha
skoi Flzikllof Tschni cal
Physics Journal e) OOCt 19
60*p-1456].

The analyzer consists of an ionization (or stripping) chamber that strips the atoms with a gas (valence stripping), a deflector (condenser or electromagnet) that deflects the ions from their initial orbit at an angle corresponding to the ion's energy, and a detection When a predetermined voltage is applied to the capacitor (or a predetermined current is passed through the electromagnet), ions with a predetermined energy are sent toward the detector. In order to record all the different particles, the voltage or current must be varied accordingly. The energy level to be measured can be defined in any way depending on the requirements of the measurement. However, the above Using an analyzer for measuring energy spectra eliminates the need for long-term measurements.

To solve this problem, it is necessary to develop a multichannel analyzer for atomic particles.

Furthermore, multi-channel analyzers for atomic particles are known (see Federal Inventor's Certificate No. 427,275 International Patent Classification GO1n 27/62, published March 26, 1975). The housing has a housing made of a conductive material, and a chamber for total ionization of atoms having an inlet and an outlet is housed within the housing (this chamber is made of a conductive material). ions of various energy levels) with a disperser adjusted to deflect the ions in the beam from their initial direction of motion at an angle that depends on the energy of the ions. A detection device is arranged successively along the beam path.

In the latter multichannel analyzer, the energy level range of the measured atomic spectrum, ie the energy resolution, is fixed and limited by the relative placement of the detectors within the detection device. That is, a multichannel analyzer built to solve one specific delta experimental theme can be used to solve problems of another theme that require more dense (or coarser) level placement across the energy sheath to be measured. Not suitable for solution. Furthermore, the energy range of this analyzer is limited by the maximum voltage or current applied to the disperser.

All known multichannel analyzers that perform dispersion in electric or magnetic fields are limited in this way.

Problems to be Solved by the Invention The purpose of the present invention is to create a multi-channel analyzer for atomic particles in which the energy resolution can be adjusted and the energy range expanded by means of a device for accelerating or trapping ions. That's true.

Means for Solving the Problem The above object is to provide an atomic particle ionization chamber (ionization chamber) made of a conductive material, arranged to form a beam of ions and having an inlet and an outlet. a disperser and a beam arranged to deflect the ions in the beam from the initial direction of operation at an angle corresponding to the energy of the beam; a multichannel analyzer for atomic particles having a device for detecting ions disposed successively along the path of the beam, the ionization chamber comprising: a device for detecting ions; A multi-channel atomic particle analyzer characterized in that it comprises an electrical lead and an electrical insulator that insulates the entire ionization chamber from the housing when a voltage is applied to the ionization chamber. .

The multi-channel analyzer for atomic particles further comprises a device for modifying the '1 field that occurs when a voltage is applied to the ionization chamber and reduces the overall focusing of the ions in the beam; Further, it is preferable that the device is disposed between the ionization chamber and the disperser.

The multi-channel analyzer for atomic particles has a series of electric field modifying devices arranged successively along the beam path such that the aperture belongs to an axis passing through the centers of the inlet and outlet of the ionization chamber. a voltage divider having the same number of links as the number of throttles and connected to the ionization chamber and the housing, each link being connected to each of the throttles; It is more preferable that

In the multichannel analyzer for atomic particles of the present invention, the energy resolution can be adjusted by applying an adjustable voltage to the ionization chamber, which is electrically isolated from the analyzer's nozzling. , the energy range is expanded.

By incorporating means to modify the electric field that occurs when voltage is applied to the ionization chamber and reduces the degree of ion focusing, the response of the analyzer can be preserved over a wide tuning range of energy resolution. can.

EXAMPLES Hereinafter, the present invention will be explained in more detail by way of preferred embodiments of the present invention with reference to the drawings.

In Figure 1, the multichannel atomic particle analyzer is
It comprises a housing 1 made of electrically conductive material with an inlet 2 for the flux of atoms to be analyzed. The housing 1 houses a screening capacitor 3 for deflecting charged particles from the flux of atomic particles entering the analyzer. Behind the selection capacitor 3 along the path of the flux is an ionization or stripping chamber 4 made of electrically conductive material having an inlet 5 and an outlet 6.

This ionization chamber is arranged to form a beam of ions by ionizing the incoming atoms in a gas, for example nitrogen or helium, supplied by a gas source 7. The ionization chamber 4 has an adjustable voltage source 9
The ionization chamber 4 is provided with an electrical lead 8 for connection to the housing 1, and an electrical insulator 10 for insulating the ionization chamber 4 from the housing 1 when a voltage is applied to the ionization chamber.

Inside the housing 1, behind the ionization chamber 4, there is a disperser 1.
1 and a detection device 12 are connected to each other and are arranged to deflect the ions in the beam from the initial traveling direction of the ions at an angle α depending on the energy of the ions.

The detection device 12 is installed to detect all ions with extremely high energy, and may be a row of detectors as shown in FIG.
oordlr,ate-responsiveplat
e, not shown].

The capacitor 3, the disperser 11, and the detection device 12 are
Individual power supplies 13, 14 . and 15.

In a preferred embodiment of the multi-channel atomic particle analyzer, means or devices 16 are provided for modifying the electric field that occurs when a voltage is applied to the ionization chamber 4 and tends to reduce the degree of focusing of the ions in the beam. is arranged between the ionization chamber 4 and the disperser 11. electric field correction device fi1
6 comprises a series of apertures 17 arranged successively along the path of the beam such that the aperture belongs to an axis 18 passing through the center of the inlet 5 and outlet 6 of the ionization chamber 4; a voltage divider 19 connected to the ionization chamber 4 and the housing 1, each link having the same number of links as the number of throttles 17;

Figures 2a and 2b are diagrams for explaining the operation of the multichannel I particle analyzer of the present invention, in which the full voltage is not applied to the ionization chamber, and when a voltage is applied to the ionization chamber and the UT channel for the case where /E, = 0.8 (Et is the energy recorded in channel I of the analyzer)! .

11 shows a chart of the distribution of ion energies recorded at I[I, II/, and V. The Y-axis represents the energy E of the particle on an arbitrary scale, and the Y-axis represents the passage coefficient N of the particle passing through the analyzer. FIG. 3 represents the dependence of the passage coefficient N (Y-axis) of particles passing through the analyzer on UT/E (ratio of voltage U7 applied to the ionization chamber to ion energy, X-axis).

Operation of the multichannel analyzer for atomic particles of the present invention *t-
This will be explained below.

In FIG. 1, a flux of atomic particles to be analyzed enters housing 1 through inlet 2. In FIG. The charged particle portion necessarily present in this flux is deflected by the capacitor 3, so that a flux consisting only of neutral particles is admitted into the ionization chamber 4. While moving through the ionization chamber 4, the particles collide with gas molecules and are stripped (deprived of valence electrons) and become ions.When the voltage applied to the ionization chamber is zero, the ionization chamber The ions formed by the ion advance toward the disperser 11.At this time, the ions have the energy of the atoms before being stripped.The disperser 11 moves the ions into an initial orbit at an angle corresponding to the energy of the ions. , each detector of detection device 12 records ions at a corresponding energy level.

The ratio of the energy recorded by the first detector (at the top level) and the energy recorded by the last detector (at the lowest level) and the distribution of energy points or energy levels within this range are analyzed. It is constant for each analyzer depending on the shape of the instrument and the position of the detector. Furthermore, the maximum energy recorded by the analyzer depends on the highest voltage (or maximum current) that can be supplied to the disperser 11. When the ionization v4 is loaded with a trapping potential (i.e., a negative potential in the case of positively charged ions) from the power supply 9, the ions flowing out from the ionization chamber 4 have an energy E-IJa (here U, <E) e The action of the analyzer after this is the same as the action described above.In the end, the maximum energy recorded in the analyzer is increased by U.Furthermore, at the same time, the maximum energy recorded in the analyzer is increased by U. If no potential is applied to the ionization chamber, this range is D'
=E0/E', i.e. the maximum value of the analyzer
mtn is the ratio of the energy recorded by the bell channel to the energy recorded by the lowest level channel. The value of Do is determined in advance by the shape of the analyzer,
D'=10-30 depending on the difference in the shape of the analyzer. The range D' when the trap potential Lia is applied to the ionization chamber 4 is substantially reduced compared to Do. In this case, the highest level channel and the lowest level channel are the energy of the particle at the ionization chamber inlet, E' = m
&x ”max +UT and E'-,, = E'm, n+ U,
' to be recorded. Here, the capture coefficient 't K = (J,
When expressed as /EE'□1□, "min =E'm1n/
("-K) Therefore,""'max/E'min=
(E'5tlax "Ut) /"'min
=E'moc""min+="'zhx ('-
K) ""@B = D'(1-K)+.

Therefore, D'=D:(1-K)+.

From this relationship, when D'=10 and K=0.8, D
' = 2.8.

When D'=30 and K=0.8, D'=6.8
That is, it can be seen that when the capture coefficient K is 0.8, the simultaneously recorded energy range is reduced to about 1/4.

It is easy to see that the energy resolution S' of the analyzer when the trapping potential is applied is s' = S',/(1-K). where SO is the energy level of the analyzer when no voltage is applied to the ionization chamber.

That is, when K=0.8, the resolution increases five times.

This can be seen from the charts in Figures 2a and b.

By varying the voltage t applied to the ionization chamber 4, ie by varying the value of K, the resolution in terms of energy can be controlled and varied over the energy range of the analyzer.

When a voltage is applied to the ionization chamber 4, the beam of ions exiting the ionization chamber becomes somewhat less focused, so that some of the particles do not reach the respective detectors of the detection device 12, which results in the analysis. affects the response of the instrument. The reason for this is that when a potential is applied to the ionization chamber 4, an electric field having a component entirely perpendicular to the axis of the ion beam is generated at the outlet of the ionization chamber. This component deflects the ions exiting the ionization chamber 4 from their initial trajectory. In order to eliminate this effect, it is necessary to reduce the electric field component perpendicular to the ion beam trajectory. Therefore, the analyzer according to the preferred embodiment of the present invention is equipped with a means or device for modifying the electric field (electric field modifying device) 16. In the electric field modifying device 16, the voltage applied to the ionization chamber 4 is It is gradually reduced to zero in the region where ion beam 17 is provided.By doing so, the electric field component that reduces the focusing degree of the ion beam is reduced the most.

The electric field modification device 16 having the aperture groups 17 evenly spaced at intervals of 3+0 has a trapping voltage of 1. Keep the response sound of the analyzer constant within the range of /E = 0.8 or less (see Figure 3).

Effects of the Invention The present invention substantially increases the overall capabilities of a multichannel analyzer of atomic particles. The present invention makes it possible to use the same spec analyzer in multiple installations with a large variety of plasmas, 41 ramets, and where the detailed study of certain regions of the atomic energy spectrum is particularly important. In certain cases, it makes it possible to solve various specific problems, namely problems in the research of techniques for additional heating of plasmas. The analyzer of the present invention allows the degree of dispersion to be controlled, so that during a single discharge in a plasma facility,
Varying the potential supplied to the ionization chamber is extremely useful for examining spectra of atoms in various details.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view of the multichannel analyzer for atomic particles of the present invention, and FIG. 2a is a diagram showing a chart recording the ion energy distribution when no full voltage is applied to the ionization chamber. FIG. 2b shows a chart recording the ion energy distribution when a voltage is applied to the ionization chamber according to the present invention, and FIG. Loaded voltage lJ
This is a diagram showing the dependence on the ratio of T and ion energy. 1...Housing, 2...Housing inlet, 3.
...Selection condenser, 4...Ionization chamber, 5...
Ionization chamber inlet, 6...Ionization chamber outlet, 7...
- Gas supply source, 8... Electrical lead part, 9... Voltage adjustable power source, 10... Electrical insulator, 11... Distributor, 12... Detection device, 13, 14, 15... Power supply, 16... Electric field correction device for correcting the electric field that reduces the degree of focusing of the ion beam, 17... Aperture of the electric field correction device, 18... Inlet and outlet of the ionization chamber axis, 19...voltage divider of the electric field modification device, I
, II, Tll. 1111, V...Each channel of the analyzer, α...Angle of deflection of ions in the beam. Below is kinpaku

Claims (1)

[Claims] 1. An atomic particle ionization chamber (4) made of a conductive material, arranged to form a beam of ions and having an inlet (5) and an outlet (6); a disperser (11) comprising a housing (1) made of an electrically conductive material and arranged to deflect the ions in the beam from the initial operating direction at an angle depending on the energy of the ions; a device (12) for detecting ions with an energy level of Voltage adjustable power supply (9
) and an electrical lead for connecting to the ionization chamber (
4) when a voltage is applied to the ionization chamber (4);
an electrical insulator (10) insulating the housing (1) from the housing (1);
A multichannel analyzer for atomic particles, comprising: 2. further comprising an electric field modification device (16) for modifying an electric field that occurs when a voltage is applied to the ionization chamber (4) and reduces the degree of focusing of ions in the beam; The electric field modification device (16) is connected to the ionization chamber (4).
) and the disperser (11). 3. The electric field modification device (16)
) a series of a plurality of apertures (17) arranged successively along the path of the beam such that the aperture belongs to an axis passing through the center of each of the inlet (5) and the outlet (6); a voltage divider (1) having as many links as said throttles (17) and connected to said ionization chamber (4) and said housing (1), each said link being connected to a respective said throttle (17); 19) The multi-channel analyzer according to claim 2, characterized in that it comprises: