JPS6037638A - Method of generating multicharge ions and ion source operating under pulse condition for enabling exeuction of same method - Google Patents

Abstract

(57) [Summary] 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 a method for producing multiply charged ions and to a source of multiply charged ions operating under pulsed conditions making it possible to carry out the method. The method of the invention therefore has many applications for particle accelerators in the biomedical and physical fields.

2. Description of the Related Art Conventionally, multiply charged ions have been produced using electronic resonance ion sources, such as micromafios (micromaf).
In an ion source, the enclosure of the ion source (cnclos old)
) is produced by introducing only a gas in which (j. is the 11th article I'IB = 2πf for the electronic zaik I cotron
- (where f is the frequency of the electromagnetic field, fTl is the mass of the electron,
e is the electric charge of an electron) and is ionized in a hypercrystalline cavity excited by a high-frequency electromagnetic field on which a magnetic field is superimposed.

Micromassios-type ion source, 9.1 details of ``This is an introduction to the generation method of multi-electron ions,'' are provided by Komisozariata Renergie Atomik ConaaI'E.
nergie Atomique) February 1, 1980
No. 2,475,798, filed in ``No. 31''.

Such an ion source may require pulses of ion flow lasting several tens of microseconds, with an interval of about 1 second, or for equipping certain particle accelerators, such as the IU-Lon type accelerator. , can be used under short pulse type action conditions.

Unfortunately, the current gain 43 and charge state gain obtained when using a micromaphios type ion source under pulsed conditions, ie, the degree of ionization 4j human body 246, is limited. However, the intensity of the multi-charged ion streams that can be extracted from these ion sources is insufficient for certain applications, particularly in the biomedical field and for particle acceleration BB.

Problems to be Solved by the Invention and Means for Solving the Problems The present invention aims to eliminate these drawbacks. For this purpose, it is proposed to use a clearly defined gas mixture which is introduced into the -1-yavity of the unexploded l9011, f-on mountain.

In particular, the present invention is comprised of elements selected from the group comprising carbon, nitrogen, oxygen, neon, argon, cryopreion, which are introduced into the enclosure of the ion source operating under pulsed conditions. A method for producing multi-charged ions by ionizing a first gas, the method comprising ionizing 11:J+l / in carbon (C02 to i:I) or nitrogen or oxygen or neon into the ion source enclosure. The present invention relates to a production method in which a neutral atom of argon or krypton, which is useful when necessary, is ionized with a second gas, which is nitrogen or oxygen, when desired.

The addition of a second gas in the gun to be ionized can increase the intensity of the produced I'7615 by a factor of about 10 compared to the use of only the gas to be ionized.

According to one preferred embodiment 1 of the method of the invention, the first gas is composed of 4'R carbon or nitrogen or neon or argon neutral atoms, and the second gas number 1 is of the gas mixture. m people are introduced into the enclosure at a rate varying between 45 and 55% in partial pressure. Preferably, the ratio is about 50%.

According to another preferred embodiment of the present invention, the first gas is krypton and the second gas is oxygen,
A gas mixture containing 94.5-95.5% oxygen in partial pressure is used.

The present invention is an input source that operates under pulsed conditions and makes it possible to carry out a method for generating multiple electrical ions, comprising:
One side is the inlet for the first gas [-1, and the other side is the exclusive inlet for the second gas, which is used for measuring the pressure inside the enclosure by a control loop incorporating a pressure indicator and a signal amplifier. It also relates to an ion source comprising an enclosure connected to a gas evaporator 11.

According to one preferred embodiment, the electronic ion source is a multi-electronic 1!θ ion source, and ionization occurs within an ultra-high frequency cavity.

DRAWINGS AND DESCRIPTION OF PREFERRED EMBODIMENTS The features and advantages of the invention are illustrated in the following non-limiting description of embodiments with reference to the accompanying drawings, which schematically illustrate the implementation of an enclosure for a multi-charged ion source according to the invention. It should be understood from this.

Electronic cycle tron and 1! (C's experience with multi-charged ion sources of the 1 mic and 1 mafiosic type has shown that the ion source is used under short pulsed conditions (-2Ti seconds approximately 50 microseconds) and neutralization of carbon or oxygen or nitrogen or neon. Heliu J for ionization of atoms and nitrogen or oxygen for ionization of 1″1° atoms in argon or krypton. When entering, the state of charge and ion flow performance (c
urrcnL performance) and the molecule rr
++I found out what I can do.

For the ionization of atoms of carbon or nitrogen; It is advantageous to use mixtures. Same + Xt C,:
, for the ionization of neutral atoms of argon, the partial pressure is 4
It is advantageous to use gas mixtures containing 5 to 55% oxygen or nitrogen, preferably 50% oxygen or nitrogen.

The ion flow dynamics of carbon, nitrogen, oxygen, neon, and argon are shown in tabular form below, where a gas mixture in a ratio of 50:50 in partial pressures is injected and withdrawn from an ion source.

For ionization of krypton atoms, the partial pressure is 94.5 to 95
．． Preference is given to using a gas mixture containing 5% oxygen. For example, with a gas mixture containing 5% krypton and 95% oxygen, a HrIl+ current of 20 II A and 1114 flows of 1 μA can be obtained.

Such a j+% increase in the extracted ion flow strength is
The i'J fit: allows applications that could not be planned with the low ion flow produced by prior art ion sources.

Thus, for example, a 1 pA N'' flow is required for biomedical applications such as cancer treatment, whereas a 3 μA Ar++2 flow after 1r) 1 charge ionization is capable of the same biomedical applications. 0.6 current levels to 100μ are widely required for some thousand nuclear physics accelerators.

The accompanying drawing shows an ion source enclosure (1) in which the ultra-high frequency power pulses are introduced by an ion shefter 2. The enclosure is connected to two gases - 19 Ll:3.4; ] Huh?j The first gas of the
One is an indication of the pressure inside the enclosure n-t G, 11;
), 2. The valve 5 used to measure the pressure inside the enclosure 1 is #i
& is getting.

The valve 5 maintains the ratio of the components of the dregs/fX compound introduced into the enclosure. 'i? Although the very high frequency -1-yavity of a single leakage IJ tron and 1r5 ion source is shown, the ion source may be of other types.

The method of generating a plasma in the cavity is based on the introduction of a gas mixture, an increase in the ion flow of the ions, and an increase in the ion flow of the ions (lj; .

If it is compatible with the action of the ion source, the enclosure may have a sinister shape, and the gas cylinders may be located, for example, at either end of the cavity or on the walls of the cavity.

When the second gas has a partial pressure of 50%, a cryogenic pump of approximately 2 [101 (41, k) is required to increase the indicating performance. In degrees, the cylinder bombing speed is zero.

[Brief explanation of the drawing]

The drawing shows an electron cyclotron resonance multi-E i according to the present invention.
17M columns of two implementations of a power ion source are shown. Explanation of drawing numbers 1...Ion, primary color enclosure, 2...Injector,
; U...Gas population, 4...Gas inlet, 5...
Valve, 6... Indicator.

Claims (6)

[Claims] (1) By ionization of a first gas composed of elements including carbon, nitrogen, oxygen, neon, argon, and krypton, which are introduced into the envelope of the ion source operating under pulsed conditions. A multi-charged ion generation method in which carbon or nitrogen gas is introduced into the ion source enclosure.
, : ionizes a neutral atom of oxygen or neon, which is helium when you want it, and also a second gas that is nitrogen or oxygen when you want to ionize a neutral atom of argon or chlorine), +7 How to generate people. (2) The first gas is composed of -C by neutral atoms of carbon, nitrogen, oxygen, neon, or argon, and the second gas is
A method according to claim 1+, wherein the gas is introduced into the enclosure in a proportion of 45 to 55% of the gas mixture. (3) The method according to the claims, wherein the ratio is about 50%. (4) The method according to claim 0, wherein the first gas is krypton, the second gas is oxygen, and a gas mixture containing 94.5 to 95.5% oxygen in partial pressure is used. . (5) Claim No. 1 (a multi-line ion source operating under pulsed conditions to enable the implementation of the method according to claim 11); On the other hand, a pressure indicator and a signal amplifier are connected to the two gas inlets, which are the inlet ports for the second gas provided for controlling the pressure inside the enclosure by the control loop containing the SJt. Multi-voltage ion source with connected enclosures. (6) Multi-Rj ion source is electronic zaik rr l-1:
In both 1! (The multi-charged ion source according to claim (5), which is a single ion source and ionization occurs within an ultra-high frequency cavity.