KR20160062978A - Apparatus and method for analysis of time dependant and spatially distributional characteristics of ion energy from laser-generated plasma - Google Patents

Abstract

The present invention relates to an apparatus and a method for analyzing the efficiency delivery of laser beam energy and the accompanying heating effect of a plasma by temporally and spatially measuring the energy features of high energy ions accelerated from a high energy density plasma generated in gas or gas cluster by virtue of the connected pulse laser beam. The apparatus is arranged in a straight line in the vertical direction around the axis of a plasma plume, which is the subject for measurement, and through a pair of vertical slits installed to move parallel to the axial (or laser incidence) direction of the plasma plume, ions are arranged to have directional nature. Ions passing through the pair of vertical slits are limited to those generated in a specific narrow spatial region of the plasma plume by vertical slits so as to have a spatial resolution. This is settled as a method for detecting flight time and lets it have a time resolution so as to collect temporal and spatial information of ion energy.

Description

Technical Field [0001] The present invention relates to an apparatus and method for analyzing the spatio-temporal characteristics of ion energy emitted from a laser induced plasma,

The present invention relates to an apparatus and method for analyzing the spatio-temporal characteristics of ion energy emitted from a laser induced plasma, and more particularly, to an apparatus and method for analyzing the spatio-temporal characteristics of ion energy emitted from a laser induced plasma, The present invention relates to an apparatus and a method for efficiently transferring laser beam energy and measuring a heating effect of a plasma according to the energy characteristics of the plasma.

Conventional methods for measuring ion energy include measuring the energy distribution of ions according to the arrival time of ions by measuring the flight time using a Faraday cup (refer to Korean Patent Laid-Open No. 10-2001-0051579) And the degree of bending of the ions was measured according to kinetic energy to measure the energy distribution of the ions (refer to Korean Patent Laid-Open No. 10-2010-0057419).

The Faraday cup used in the former method is generally mounted in an ion implantation apparatus in an ion implantation process. The Faraday cup has a graphite cup located in the path of the ion beam, And the energy in the ion beam injected through the portion is measured.

The Thompson parabolic ion analyzer is a type of analyzer that applies an electric field and a magnetic field parallel to each other. The ion is incident perpendicularly to the electric field and the magnetic field. The detector is located at a certain distance from the electric field and the magnetic field. As shown in FIG. At this time, the ions are deflected in a direction parallel to the electric field and simultaneously deflected in a direction perpendicular to the magnetic field. Since the distance the ion is deflected is smaller the higher the energy of the ion, the energy of the ion can be measured using the deflected distance.

However, information obtained through this can only obtain information on the energy distribution corresponding to the average value of the generated total ions, and information on the spatial ion energy can not be obtained. Therefore, it is necessary to study the spatio-temporal characterization of new effective ion energy in order to obtain the spatial distribution of the ion energy of plasma simultaneously with the information about the temporal distribution.

Korean Patent Publication No. 10-2007-0019297

It is an object of the present invention, which is devised to solve the above-described problems, to provide a new effective space-time space time measuring apparatus and method for simultaneously obtaining spatial distribution of ion energy of plasma with information on temporal distribution.

According to an aspect of the present invention, there is provided a spraying apparatus including: a spray nozzle for spraying a gas or gas cluster; A laser beam supply unit for forming a plasma plume for supplying a laser beam to the gas or gas cluster injected by the injection nozzle; A pair of vertical slits movable in parallel with a longitudinal direction of the plasma plume formed in the incident direction of the laser beam and perpendicular to the longitudinal direction of the plasma plume; And a plurality of vertical slits disposed at a rear end of the pair of vertical slits, wherein the ions are transmitted through the pair of vertical slits in a direction perpendicular to the longitudinal direction of the plasma plume, A horizontal slit formed parallel to the longitudinal direction of the substrate; Amplifying means provided at a rear end of the horizontal slit for inducing electron amplification with respect to a flow of ions; An ion detector disposed downstream of the amplifying means for detecting a current emitted by the amplifying means; And a signal processor for processing and storing the signal detected by the ion detector. The apparatus for analyzing the spatio-temporal characteristics of ion energy emitted from a laser induced plasma.

As a result, the ions are aligned in a direction through a pair of vertical slits so that the ions passing through the double slit are limited to those generated in a specific narrow space region of the plasma plasma, Resolution.

More specifically, the slit holes formed in the pair of vertical slits are parallel to each other, and the axes and the planes thereof are vertically arranged at a constant distance from each other on the same axis, so that a pair of narrow band- Due to the viewing angle along the holes, spatial resolution is obtained with respect to the vertical direction of the narrow band. The flow of the ions discharged through the two slit holes in a narrow band shape is a horizontal slit in which the slit holes are arranged in the vertical direction of the band, that is, perpendicular to the two slit holes, So that the cross-sectional area of the ion flow is reduced.

As a result, the cross-sectional area of the ion flow reaching the amplification means is appropriately reduced so that the flow of ions of the same area is always sufficiently contained in the incident surface of the amplification means, so that two vertically- (Or laser incidence) direction of the optical axis. Such a pair of vertical slits move finely a certain distance after the pulsed laser beam is irradiated each time, and the electric ion signal generated by the ion detector is synchronized with the time when the laser beam is irradiated and stored in the signal processor, Therefore, it is possible to obtain the temporal information of the ions with respect to the traveling direction of the plasma plasma.

The laser beam supply unit includes a laser irradiator for irradiating a laser beam and a non-shrinkable lens for condensing the laser beam and supplying the laser beam to a gas or gas cluster injected by the injection nozzle.

Further, the amplifying means is a microchannel plate.

The ion detector is a Feather Ray cup.

The pair of vertical slits move in a direction parallel to the longitudinal direction of the plasma plume, with the slit width of the vertical slit being a moving distance.

In another aspect of the present invention, there is provided a method for analyzing the spatio-temporal characteristics of ion energy emitted from a laser induced plasma using the spatiotemporal characterization apparatus, comprising the steps of: a) supplying a laser beam to a gas or gas cluster; b) blocking the flow of ions in a direction parallel to the longitudinal direction of the plasma plume formed in the direction of incidence of the laser beam so as to have directionality; c) blocking the ions having the directionality and transmitted therethrough in a direction perpendicular to the longitudinal direction of the plasma plume to restrict ions into a flow having a constant area; d) inducing electron amplification for the flow of ions confined to the flow having the constant area; e) detecting a current emitted to the electron amplification; And f) processing and storing the signal detected by the ion detector, wherein in a step b), moving the region blocking the flow of ions in a direction parallel to the longitudinal direction of the plasma plume, Wherein the ion energy is generated by a laser induced plasma.

As described above, according to the embodiment of the present invention, it is possible to obtain information on the amount of generated ions and the energy distribution characteristics that vary along the longitudinal axis of the plasma plasma. Accordingly, it is possible to optimize the characteristics of the laser beam and the spatial distribution characteristics of the gas or cluster so that the energy of the laser beam is spatially absorbed within the plasma and the amount and energy of the generated ions are increased.

The result is a tool for studying new methods of laser energy transfer and plasma heating, which are ultimately necessary for the development of laser fusion neutron sources using Coulomb explosions as a result of the interaction of laser beams with gas or gas clusters containing deuterium. can do.

FIG. 1 is a schematic diagram of an analyzing apparatus for obtaining time-space characteristic information of ion energy emitted from a laser induced plasma according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components, and the same reference numerals will be used to designate the same or similar components. Detailed descriptions of known functions and configurations are omitted.

In FIG. 1, reference numeral 100 denotes a spatiotemporal characteristic analyzer 100 according to the present invention. The spatiotemporal characteristic analyzer 100 mainly includes a plume forming unit for forming a plasma plume, an ion implanting unit for limiting the directionality of ions emitted from the plasma plume formed in the plume forming unit, And an analyzing unit for obtaining signal information from the ions supplied from the injecting unit.

The plume forming section comprises an injection nozzle 104 for injecting a gas or gas cluster 4 and a laser beam 2 focused on a gas or gas cluster 4 injected by the injection nozzle 104 And a laser beam supply unit for forming a plasma plume (5).

The gas or gas cluster 4 may be an inert gas such as argon. The laser beam supply unit includes a laser irradiating device (not shown) for irradiating the laser beam 1 and a gas or gas cluster 4 which is focused by the jetting nozzle 104 to focus the laser beam 1 And a non-axial port 102 for supplying the laser beam 2 focused on the non-axial port. As the laser beam 1, a pulsed laser can be used. As a result, the plasma plume 5 is formed in a substantially bar shape in the incident direction of the focused laser beam 2.

The ion implantation unit may include a pair of vertical slits 106 and 108 that are movable in parallel with the longitudinal direction of the plasma plume 5 and are formed perpendicular to the longitudinal direction of the plasma plume and a pair of vertical slits 106 and 108 And a plurality of vertical slits (106, 108) disposed at a rear end of the plasma plume (5), the plasma plume (5) having a directional characteristic and shielding ions transmitted therethrough in a direction perpendicular to the longitudinal direction of the plasma plume And a horizontal slit 110 formed parallel to the longitudinal direction of the substrate 5.

In addition, the pair of vertical slits 106 and 108 are arranged in a line spaced apart from each other along a virtual reference line 3 as shown in Fig. 1, and this reference line 3 can be interpreted as a moving direction of ions . The pair of vertical slits 106 and 108 are simultaneously moved in parallel with the longitudinal direction of the plasma plume 5. In other words, it can be understood that the reference line 3 moves.

The horizontal slit 110 is formed to have a slit hole parallel to the longitudinal direction of the plasma plume 5 at a distance longer than the distance that the pair of vertical slits 106 and 108 move in the longitudinal direction of the plasma plume 5.

When the pair of vertical slits 106 and 108 move in a direction parallel to the longitudinal direction of the plasma plume 5, the slit widths of the slit holes formed in the vertical slits 106 and 108 may be shifted with a movement interval. As a result, the signal information can be continuously obtained without overlapping in the longitudinal direction of the plasma plume 5.

The ions are aligned in a direction by the pair of vertical slits 106 and 108 so that the ions passing through the double slit are limited to those generated in a specific narrow space region of the plasma plasma to have a spatial resolution, Ions passing through the ion implantation unit can be supplied to the analyzer having a constant area due to the combination of the horizontal slits (106, 108) and the horizontal slit (110).

In more detail, the slit holes formed in the pair of vertical slits 106 and 108 are parallel to each other, and the axes and the planes thereof are vertically arranged at a constant distance from each other on the same axis, whereby a pair of narrow bands The viewing angle along the slit hole has a spatial resolution with respect to the vertical direction of the narrow band. The flow of ions emitted through the two vertical slits 106 and 108 in a narrow band shape is a horizontal slit 110 in which two slit holes and vertical slit holes are arranged, The cross-sectional area is reduced.

As a result, the cross-sectional area of the ion flow reaching the amplification means is appropriately reduced so that the flow of ions of the same area at all times is sufficiently contained in the incident surface of the amplification means, so that the two vertical slits 106, 108 Is parallel to the longitudinal axis (or laser incidence) of the plasma plume 5, it provides effective comparison information.

The analyzer comprises amplifying means provided at a rear end of the horizontal slit 110 to induce electron amplification with respect to a flow of ions, an ion detector provided at a downstream end of the amplifying means and detecting a current emitted by the amplifying means, And a signal processor 116 for processing and storing the signal detected by the ion detector.

The amplification means may be a microchannel plate 112, and ions passing through the ion implantation unit may pass through the microchannel plate 112 to emit amplified current.

As the ion detector, a Faraday cup 114 can be used. In the Faraday cup 114, the amplified current can be detected while passing through the microchannel plate 112, and the detected current is converted into a signal to the signal processor 116 and stored.

The above operation is continued while the pair of vertical slits 106 and 108 move in the direction of the arrow shown in Fig. 1 (direction parallel to the longitudinal direction of the plasma plume 5) It is possible to store the obtained signal with respect to the whole.

The spatiotemporal characteristic analyzer 100 according to the embodiment of the present invention is basically configured as described above. Hereinafter, a method for analyzing the spatiotemporal characteristic using the spatiotemporal characteristic analyzer 100 will be described.

First, when the laser beam 1 is irradiated onto the non-shrink bottle 102 by the laser irradiation device (not shown), the non-shrink bottle 102 converges the laser beam 1 and is ejected from the injection nozzle 104 To the gas or gas cluster (4). As a result, a plasma having a high energy density is generated to form the plasma plume 5. At this time, when the excited electrons in the plasma plume 5 absorb the energy of the laser beam and are separated, the remaining ions are emitted to the four directions without energy due to the Coulomb explosion.

A pair of vertical slits 106 and 108 disposed in the reference line 3 and facing the plasma plume 5 cuts off the flow of ions in the longitudinal direction of the plasma plume 5 to form a pair of vertical slits 106 and 108 ) Of the thin ions having the directivity of only the ions passing through the slit grooves of the thin film. The flow planes of these ions are composed only of ions emitted from a localized region spatially limited with respect to the longitudinal direction of the plasma plume 5, and have a unique partial characteristic of the plasma plume 5 corresponding to the space. The horizontal slit 110 blocks the flow surface of the ions upward and downward to restrict the flow of ions having a constant area. As a result, all of the ions emitted through the slits enter the effective area of the front surface of the microchannel plate 112.

The flow of ions in the microchannel plate 112 induces electron amplification and the amplified current is emitted through the rear surface of the microchannel plate 112 and is detected by the Faraday cup 114.

The signal processor 116 electrically connected to the Faraday cup 114 processes and stores the signal.

The position of the plasma plume is determined by moving the pair of vertical slits 106 and 108 in accordance with the view that is changed when the horizontal slit 106 or 108 is moved in the direction of the arrow shown in Fig. 1, that is, the longitudinal direction of the plasma plume 5, 106 and 108 are continuously scanned while continuously storing the ion signal, plasma information analyzed spatially with respect to the entire plasma plasma 5 is obtained.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. In addition, the present invention is not limited to the above-described embodiments, and various modifications and changes may be made thereto by those skilled in the art to which the present invention belongs. Therefore, the spirit of the present invention should not be construed to be limited to the above-described embodiments, and all of the equivalents or equivalents of the claims, as well as the claims of the following claims belong to the scope of the present invention.

1: laser beam
2: focused laser beam
3: Reference axis
4: Gas or gas cluster
5: Plasma Plume
100: Spatio-temporal characterization device
102:
104: injection nozzle
106, 108: vertical slit
110: Horizontal slit
112: Microchannel plate
114: Faraday cup
116: Signal processor

Claims (6)

A jet nozzle for jetting a gas or gas cluster;
A laser beam supply unit for forming a plasma plume for supplying a laser beam to the gas or gas cluster injected by the injection nozzle;
A pair of vertical slits movable in parallel with a longitudinal direction of the plasma plume formed in the incident direction of the laser beam and perpendicular to the longitudinal direction of the plasma plume;
And a plurality of vertical slits disposed at a rear end of the pair of vertical slits, wherein the ions are transmitted through the pair of vertical slits in a direction perpendicular to the longitudinal direction of the plasma plume, A horizontal slit formed parallel to the longitudinal direction of the substrate;
Amplifying means provided at a rear end of the horizontal slit for inducing electron amplification with respect to a flow of ions;
An ion detector disposed downstream of the amplifying means for detecting a current emitted by the amplifying means; And
And a signal processor for processing and storing the signal detected by the ion detector.
The apparatus according to claim 1, wherein the laser beam supply unit includes a laser irradiator for irradiating a laser beam, and a non-shrinkable lens for condensing the laser beam and supplying the laser beam to a gas or gas cluster injected by the injection nozzle An apparatus for analyzing the spatio - temporal characteristics of ion energy emitted from a laser induced plasma.
The apparatus of claim 1, wherein the amplifying means is a microchannel plate.
The apparatus of claim 1, wherein the ion detector is a fader ray cup.
2. The plasma display apparatus according to claim 1, wherein the pair of vertical slits are moved in a direction parallel to the longitudinal direction of the plasma plume, with the slit width of the vertical slit being a moving distance. Device.
A method for analyzing the spatio-temporal characteristics of ion energy emitted from a laser induced plasma using the spatiotemporal characteristic analyzer according to any one of claims 1 to 5,
a) supplying a laser beam to a gas or gas cluster;
b) blocking the flow of ions in a direction parallel to the longitudinal direction of the plasma plume formed in the direction of incidence of the laser beam so as to have directionality;
c) blocking the ions having the directionality and transmitted therethrough in a direction perpendicular to the longitudinal direction of the plasma plume to restrict ions into a flow having a constant area;
d) inducing electron amplification for the flow of ions confined to the flow having the constant area;
e) detecting a current emitted to the electron amplification; And
f) processing and storing the signal detected by said ion detector,
and the step c) is repeatedly carried out while the region blocking the flow of the ions is moved in the direction parallel to the longitudinal direction of the plasma plume in the step b), and the time-space characteristic analysis of the ion energy emitted from the laser induced plasma Way.

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