JPS5868857A - Ion source - Google Patents

Abstract

PURPOSE:To obtain an ion source with high ionized efficiency by arranging an electric field ionized means in close vicinity to a target. CONSTITUTION:The argon ions generated from an ion gun 1 and accelerated by it are incident on a bombardment chamber 3 that is filled with argon gas. A part of them collides with argon gas, is deprived of charge, changes into a high speed neutral particle, is introduced in an ionized box 5, and is incident on a target 6. The surface of the target 6 is coated with a sample in which an ionized material is mixed. The sample is bombarded by a neutral argon atmic beam, is beaten and driven out from above the target, and is ionized, but part of it is not ionized but is floated. Positive high voltage is applied to a linear member 7 and negative high voltage is applied to an electrode 9. Since an electric field is concentrated in the vicinity of the linear member 7, a suspended particle is ionized by this intense electric field.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ion source suitable for use in an I4 mass spectrometer, and particularly to an ion source that bombards a sample with high-speed neutral particles to ionize the sample.

In recent years, a mixed sample of, for example, glycerin and a substance to be ionized is coated on a conductive target, the sample is bombarded with high-speed neutral particles, and the substance to be ionized is struck by the energy of the neutral particles. However, an ion source with further ionization has been introduced.

This ion source is used as an ion source for mass spectrometers, and has many advantages such as a high rate of ion generation, and because it bombards the sample with neutral particles, there is no charge-up and even insulating samples can be easily ionized. It has excellent characteristics. However, in this ion source, a part of the ionized material (J
Ionization does not reach 0 or 0, and it floats as a neutral particle...
T, and apply a layer to any member A in the ionization chamber.

An object of the present invention is to provide an ion source with high ionization efficiency.

In the present invention, an electric field ionization means is placed close to the ion source, which ionizes the C1 fractured ionized substance held in the C target by bombarding it with high-velocity neutral particles. It has all the features. The ionizing means includes, for example, a thin wire member disposed close to the target and having approximately the same potential as the target;
Particles of the ionized substance that are placed close to the linear member and are ejected from the target but not ionized due to the application of a high voltage between the linear member and the nuclear cell. The particles concentrated in the linear member are ionized by the ions, thus increasing the ionization efficiency of the ion source.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to all the accompanying drawings.

In the figure, 1 is an argon ion gun, and the argon ions generated in the ion gun are accelerated by an acceleration chamber (2). They enter the collision chamber 6, and a part of them collides with the argon gas and is deprived of electric charge, becoming high-speed neutral particles.An electrostatic deflection plate 4 is arranged at the bottom of the collision chamber 6. The argon ions 1 that have passed through the collision chamber 3 are deflected and removed by the deflection plate 4, and a target 6 made of copper, for example, is placed in the electrical ionization box 5, and a target 6 made of copper, for example, is placed in the ionization box 5. A conductive wire member 7 is placed close to the elbow ionization box 5, target 6, and wire member 7, and a voltage of 3 KV, for example, is applied from a power source 8.In addition, a U wire KB material is applied to the elbow ionization box 5, target 6, and wire member 7. 7 In the configuration shown above, a considerable portion of the argon ions generated and accelerated from the ion gun 1 mainly collide with argon atoms in the collision chamber 6 and lose charge.
A mixed beam of high-speed argon atoms and argon ions that did not lose their charge in the collision chamber was released from I() to 0. However,
The argon ions IJljl) are f[
; As a result, only the neutral argon atomic beam is incident on the target 6. 11 on the surface of the target
For example, a sample containing a complete mixture of substances to be ionized in glycerin is applied, and the sample is bombarded with a beam of neutral argon atoms. Objects on the sample surface that have received the impact are ejected from the target and further ionized by the energy 1 of the neutral argon atomic beam. The ionized T-particles are extracted by the electrode 9, further accelerated, and guided to the mass spectrometer. By the way, a part of the ionized substance ejected from the carbon target does not reach the stage of ionization and remains floating. Here, a positive high voltage of 1 is applied to the wire member 7, and 1! Since a negative high voltage is applied to the electrode 9, an electric field is concentrated in the vicinity of the wire member 7, and the floating particles 1 are ionized by the strong electric field 1 and immediately accelerated by the electrode 9. In this way, in the present invention, material particles that are not ionized even by the impact of high-velocity neutral particles can be ionized by tW, so the ionization efficiency can be increased. . Therefore, sufficient mass spectrometry can be performed even when the amount of sample is small, and even substances that are difficult to ionize due to the impact of high-speed primary particles can be ionized with the aid of an electric field.

Although the present invention has been fully described in detail above, the present invention is not limited to the embodiments described above and can be modified in many ways. For example, instead of the linear member 7, a grid-like or mesh-like linear member may be arranged, or a linear member having a large number of needle-like members used in a conventional field desorption ion source. You can also use sound.

[Brief explanation of drawings]

The accompanying drawings show a single foam example of the present invention [4]. 1: Argon ion gun, 2: Additive electrode, 3: Collision chamber, 4
: Electrostatic deflection plate, 5: Ionization box, 6: Target, 7:
Linear member, 8: power source, 9: electrode, 10: 'α source. Patent Applicant Japan Electronics Co., Ltd. Representative Tadashi Kasei
No. 89, 2 shots ty] Name of ion source 3 Patent for the person making the correction Issue + m Address 1418 Nakagami-cho, Akishima City, Tokyo (Location 042)
5 (43) 1111) Name (427) JEOL Co., Ltd. 4 Amendment Subject Specification 1 Page 6, between lines 8 and 9, insert one or less sentences. In addition, in the above-mentioned embodiment, the turret belt was fixed, but for example, a movable belt was used as the turret, and this belt was used to develop and hold the effluent from the liquid chromatograph. By continuously feeding one sample into the ionization box 5 and irradiating it with neutral particles, it becomes possible to sequentially ionize the sample containing one sample of the effluent and conduct an analysis.''

Claims (1)

[Claims]L: Bombarding the C1-depleted ionized substance held on the target with high-velocity neutral particles. Ion source with all ionization means arranged. 2. The field ionizing means includes a linear member disposed close to the target and having substantially the same potential as the target, and an IM 0. claim 1, wherein a high voltage is applied between the linear member and the electrode.
Ion source as described in section.