Patent Description:
X-ray is a kind of electromagnetic radiation with a very short wavelength in a range of about <NUM>-<NUM> angstroms, which is between ultraviolet and gamma rays. X-ray represents high penetration capacity and is able to penetrate various materials that are opaque to the visible light. X-rays with shorter wavelengths represent greater energy and are also known as hard X-rays. X-rays with longer wavelengths represent lower energy and are known as soft X-rays. Generally speaking, with a wavelength less than <NUM> angstroms, the X-ray is known as super-hard X-ray, with the wavelength in the range of <NUM>-<NUM> angstroms as hard X-ray, and with the wavelength in the range of <NUM>-<NUM> angstroms as soft X-ray.

In recent years, soft X-rays have been widely used in many scientific fields. Especially in the fields of soft X-ray microscopic imaging and soft X-ray projection lithography technologies, soft X-rays with low debris, high brightness, and high stability are increasingly needed. In addition, in atomic spectroscopies, molecular spectroscopies, plasma physics or other subjects, soft X-ray light sources are typically indispensably required by scientific experiments, therefore, the demands for the applications of soft X-ray light sources have been rapidly increased.

In the early stage, the laser-plasma soft X-ray light source adopts a solid metal target, which will produce a lot of metal debris which may in turn damage the optics adjacent to the light source, such that it is unable to perform normal functions, and the effect is greatly degraded, leading to the incapability of normal operation of the light path in the experiments or the instruments. With the development of the technologies, therefore, liquid microfluidic targets have begun to be widely used. In the prior art, gas liquefaction is mainly realized by contacting a semiconductor refrigeration device with a pipe through which working gas passes. There are two shortcomings in this kind of refrigeration device: First, the refrigeration capacity of the semiconductor refrigeration device cannot reach the level of liquefying some working gases with a low liquefaction point (for example, nitrogen with a liquefaction point - <NUM> under the normal pressure), even under high pressure. Second, the refrigeration device does not represent high efficiency in that the use of contact between a spiral gas pipe and the metal heat conductive plate of the semiconductor refrigeration sheet does not represent a high heat transfer efficiency, which results in an inconsistency between the temperature in the gas pipe and that of the refrigeration sheet. For most working gases with a low liquefaction point, even after successful liquefaction, nitrogen crystallization will occur due to the evaporation and condensation effect, making it difficult to maintain a stable jet of low-temperature liquid flow.

Meanwhile, in the prior art solutions, there is no dedicated collection device for the liquid micro-flow. Instead, only an empty pump pipe is connected to the bottom of the cavity directly below the vertical position of the liquid flow, such that the vacuum degree in the vacuum target chamber cannot be maintained at a high level. Since the soft X-ray is of low-energy X-ray with a long wavelength and strong absorption in the air, the lack of vacuum in the vacuum target chamber will cause the soft X-rays generated by the laser-plasma to be partially absorbed, and thus the light intensity of the light will be weakened.

In addition, in the prior art solutions, the liquid microfluidic target devices of fixed and non-adjustable structure are provided, in which the position of the nozzle is fixed and non-adjustable after installation. However, various applications of soft X-rays, such as soft X-ray microscopes, require a light source of high-degree geometric symmetry. If there is a manufacturing error of the light source device or an offset of the nozzle position due to the aging of the instrument, it will directly affect the application of the instrument with reduced application performance.

In short, the soft X-ray light source of liquid microfluid target laser plasma in the prior art has shortcomings of insufficient refrigeration performance of the liquid microfluid target, poor liquid flow stability, and poor performance in terms of size, spatial stability, and brightness of the laser-plasma or the like, which may not meet the application requirements. <CIT> discloses an apparatus for producing liquid or solid xenon. <CIT> discloses a fluid nozzle system and method in an emitted energy system for photolithography.

The object of the invention is to provide a soft X-ray light source, which is able to solve at least one of the above-mentioned technical problems.

The present invention is defined by independent claim <NUM>; the dependent claims describe embodiments of the present invention. To address the above-mentioned technical issues, in the disclosure a soft X-ray light source is proposed, comprising a vacuum target chamber, a refrigeration cavity, and a nozzle, wherein the refrigeration cavity and the nozzle are received in the vacuum target chamber, and the nozzle is arranged in the refrigeration cavity, wherein the vacuum target chamber comprises a t-branch tube and a multi-channel tube. The t-branch tube has a first outlet and a second outlet opposed to each other as well as a third outlet located between the first outlet and the second outlet, wherein the first outlet is connected to a mounting plate through which a refrigerant inlet pipe, a refrigerant outlet pipe, and a working gas pipe respectively pass and are connected to the refrigeration cavity and wherein the third outlet is connected to a vacuum extraction device. The multi-channel tube comprises a top opening and a bottom opening opposed to each other as well as a plurality of side openings located between the top opening and the bottom opening, wherein the top opening is tightly connected to the second outlet, wherein a vacuum outlet is provided at the bottom opening, wherein the nozzle has a position corresponding to those of the side openings, wherein provided under the nozzle is a groove which is fixed by an adapter arranged at the vacuum outlet, and wherein the groove is in communication with the vacuum outlet.

According to an embodiment of the present application, arranged below the refrigeration cavity is an adapter connected to the nozzle.

According to an embodiment of the present application, a temperature sensor is provided at the nozzle.

According to an embodiment of the present application, the adapter is provided with a heat conduction rod connected to the refrigeration cavity.

According to an embodiment of the present application, the adapter is provided with a heat conduction tube in communication with the refrigeration cavity.

According to an embodiment of the present application, the groove is provided on a top portion of a frustum fixedly connected to the adapter.

According to an embodiment of the present application, a heater, such as a resistance wire, is provided at the periphery of the nozzle.

According to an embodiment of the present application, the soft X-ray light source comprises a mounting plate, a bellows, and a three-dimensional displacement mechanism. The mounting plate is arranged above the vacuum target chamber and is provided with a refrigerant inlet pipe, a refrigerant outlet pipe, and a working gas pipe passing through the mounting plate, wherein the refrigerant inlet pipe and the refrigerant outlet pipes are in communication with the refrigeration cavity, and the working gas pipe passes through the refrigeration cavity and is connected to the nozzle. The bellows is arranged between the mounting plate and the vacuum target chamber, wherein the refrigerant inlet pipe, the refrigerant outlet pipe, and the working gas pipe all pass through the bellows. The three-dimensional displacement mechanism is arranged between the mounting plate and the vacuum target chamber.

According to an embodiment in the disclosure, the three-dimensional displacement mechanism comprises a first displacement adjuster, a second displacement adjuster, and a third displacement adjuster, which are arranged between the mounting plate and the vacuum target chamber and respectively, control the movements of the mounting plate in three mutually perpendicular directions.

According to an embodiment of the present application, the soft X-ray light source further comprises a first mounting plate, a second mounting plate, and a third mounting plate arranged in parallel with each other and sleeved about the bellows, wherein the first mounting plate is movably fastened to the mounting plate by the third displacement adjuster, the second mounting plate is movably fastened to the first mounting plate by the second displacement adjuster and is movably fastened to the third mounting plate by the first displacement adjuster, and third mounting plate fastened to the vacuum target chamber.

According to an embodiment of the present application, the first displacement adjuster comprises a first bracket fastened to the third mounting plate, a first pusher fastened to the first mounting plate and aligned with the second mounting plate, a first rail fastened to the third mounting in a first direction, and a first rail groove fastened to the underside of the second mounting plate and in slidable cooperation with the first rail.

According to an embodiment of the present application, the second displacement adjuster comprises a second bracket fastened to the second mounting plate, a second pusher fastened to the second mounting plate and aligned with the first mounting plate, a second rail fastened to the second mounting in a second direction perpendicular to the first direction, and a second rail groove fastened to the underside of the first mounting plate and in slidable cooperation with the second rail.

According to an embodiment of the present application, the first displacement adjuster comprises a plurality of screws fastened to the first mounting plate and evenly arranged in a third direction perpendicular to the first direction and the second direction, and a plurality of nuts, wherein the mounting plate is fastened to the screws by engagement of the nut and the screws.

According to an embodiment of the present application, the first displacement adjuster may have a plurality of stepping devices arranged in a third direction perpendicular to the first direction and the second direction, wherein the mounting plate is fastened to the first mounting plate by the stepping devices.

According to an embodiment of the present application, the first pusher or the second pusher may have a micrometer head.

According to an embodiment of the present application, the working gas pipe has a section forming a condensing cavity with an enlarged cross-sectional area, wherein the condensing cavity is at least partially located in the refrigeration cavity.

To address the above-mentioned shortcomings, the soft X-ray light source in the disclosure is provided with direct contact between the refrigerant in the refrigeration cavity and the through pipe through which the working gas passes, for the purpose of cooling. The refrigeration effect may be adjusted upon the selection of refrigerants, which for example may reach an extremely low temperature and thus liquefy the working gas having a relatively low liquefaction point, such as liquid nitrogen. The heating is performed at the outlet of the nozzle by means of the resistance wire around the periphery of the nozzle, in order to improve the stability of the liquid flow. Meanwhile, in the disclosure, a multi-channel vacuum system is proposed, in which the metal frustum under the nozzle is cooperation with the vacuum pump pipelines to prevent the low-temperature micro-flow from further vaporizing during the flow process which will otherwise reduce the vacuum degree and cause the consumption of soft X-rays, while a further set of vacuum pumps is arranged above the cavity of the vacuum target chamber for extraction of the gas in the cavity so as to maintain a high-degree vacuum in the cavity. In addition, the device is provided with such a three-dimensional displacement mechanism to adjust the position of the nozzle in the X-axis, Y-axis, and Z-axis directions, thereby realizing the adjustment of the geometric position of the light source.

The accompanying drawings with reference to the embodiments or state of art will be described for the purpose of demonstrating the embodiments in the disclosure and the state of art. It is apparent that the drawings as shown are merely illustrative of some embodiments as recited in the disclosure. It should be understood by those skilled in the art that various alternatives to the drawings as shown may be appreciated, without creative work involved.

In the following, the application will be described further with reference to embodiments. It should be understood that the following embodiments are only for illustrative instead of limited purposes.

Notably, when a component or element is referred to as being "disposed on" another component or element, it can be directly disposed on the other component or element or there may be an intermediate component or element. When a component or element is referred to as being "connected or coupled" to another component or element, it may be directly connected or coupled to the other component or element or there is an intermediate component or element. The term "connection or coupling" used herein may include electrical connection or coupling and/or mechanical or physical connection or coupling. The term "comprise or include" used herein refers to the existence of features, steps, components or elements, but does not exclude the existence or addition of one or more further features, steps, components, or elements. The term "and/or" used herein includes any and all combinations of one or more of the related listed items.

Unless otherwise indicated, all the technical and scientific terms used herein have general meaning as commonly understood by those skilled in the technical field related to the disclosure. The terms used herein are for the purpose of describing specific embodiments, but not intended to limit the invention.

In addition, the terms "first", "second", "third" or the like used herein are only for the purpose of description and to distinguish similar objects from each other, which do not express the sequence thereof, nor can they be understood as an indication or implication of relative importance. In addition, in the description in the disclosure, unless otherwise specified, "a plurality of" means two or more.

<FIG> is a three-dimensional schematic diagram of a soft X-ray light source according to an embodiment of the present application. It can be seen from <FIG> that the soft X-ray light source provided in the present application comprises a three-dimensional displacement mechanism, a vacuum target chamber, a refrigeration mechanism, and a light-generating mechanism, which will be described in detail with reference to the drawings.

In <FIG>, the three-dimensional displacement device comprises a mounting plate <NUM> in a shape of a plate, a bellows <NUM>, a first flange <NUM>, a first displacement adjuster <NUM>, a second displacement adjuster <NUM>, and a third displacement adjuster <NUM>. The bellows <NUM> has a cylindrical shape and is configured to be expandable and collapsible in an axial direction thereof. The bellows <NUM> has a sealed top portion arranged on a lower surface of the mounting plate <NUM>, and a bottom portion tightly connected to the first flange <NUM>, such that the mounting plate <NUM>, the bellows <NUM>, and the first flange <NUM> form a closed, substantially cylindrical space. The cylindrical space has a vertical centerline, which is the direction vertical to the paper showing the figure, defined as the Z-axis direction, and two mutually perpendicular directions in a plane perpendicular to the Z-axis direction defined as the X-axis and Y-axis directions, respectively. The first flange <NUM> is provided with a plurality of first screws <NUM> extending in the Z-axis direction. Arranged on top portions of the first screws is an annular third mounting plate <NUM> which is provided with the first displacement adjuster <NUM>. Provided is a second mounting plate <NUM> having the same shape as and parallel to the third mounting plate <NUM>. The second mounting plate <NUM> is positioned above the third mounting plate <NUM> and is connected to the third mounting plate <NUM> by means of the first displacement adjuster <NUM>. The second mounting plate <NUM> is provided with a second displacement adjuster <NUM>. The first mounting plate <NUM> has the same shape as and is parallel to the second mounting plate <NUM>. The first mounting plate <NUM> is positioned above the second mounting plate <NUM> and is connected to the second mounting plate <NUM> by means of the second displacement adjuster <NUM>. The first mounting plate <NUM>, the second mounting plate <NUM>, and the third mounting plate <NUM> are substantially stacked over each other and have through holes of the same size, respectively, in which the bellows <NUM> is received. The first mounting plate <NUM> is provided a plurality of, such as three (<NUM>), second screws <NUM> extending in the Z-axis direction, to which the mounting plate <NUM> is fastened by means of an adjusting nut <NUM>, as a third displacement adjuster, which is configured to adjust the position of the mounting plate <NUM> in the Z axis direction. The mounting plate <NUM> is also provided with a working gas pipe <NUM>, a refrigerant outlet pipe <NUM>, and a refrigerant inlet pipe <NUM>, which pass through the mounting plate <NUM> from the outside and are inserted into the bellows <NUM>.

Further, in <FIG>, the vacuum target chamber comprises a t-branch tube <NUM> including three outlets, i.e., a top outlet, a bottom outlet, and a side outlet, and a multi-channel tube <NUM>. Provided between the top outlet and the bottom outlet is a cylindrical space extending in the Z-axis direction, with which the side outlet is in communication. Arranged at the top outlet is a second flange <NUM>, arranged at the side outlet is a third flange <NUM>, and arranged at the bottom outlet is a fourth flange <NUM>. The first flange <NUM> and the second flange <NUM> are tightly connected to each other by a gasket and a bolt. The multi-channel tube <NUM> comprises an upper opening, a lower opening, and a plurality of side openings. Provided between the upper opening and the lower opening is a cylindrical space extending in the Z-axis direction, with which the side openings are in communication. Meanwhile, arranged at the upper opening is a fifth flange <NUM>, arranged at the lower opening is a sixth flange <NUM>, and arranged at the side openings are the respective flanges <NUM>, <NUM> or the like. The firth flange <NUM> and the fourth flange <NUM> are tightly connected to each other by a gasket and a bolt. The sixth flange <NUM> is provided with a vacuum exhaust port <NUM> in the central portion thereof. It should be noted by those skilled in the art that where the first flange <NUM> is tightly connected to the second flange <NUM>, the cylindrical space in the bellows <NUM> above the first flange <NUM> is not in communication with the cylindrical space in the t-branch tube <NUM> under the second flange <NUM>. Where the fourth flange <NUM> is tightly connected to the fifth flange <NUM>, the cylindrical space in the t-branch tube <NUM> above the fourth flange <NUM> is in communication with the cylindrical space in the multi-channel tube <NUM> under the fifth flange <NUM>. Arranged at the plurality of side openings on the side face of the multi-channel tube <NUM>, there may be a CCD holder <NUM>, a CCD adapter <NUM>, a laser shield <NUM>, observation windows <NUM>, <NUM>, or the like, which are commonly used by those skilled in the art and will not be elaborated in detail.

Further, <FIG> is a schematically, partially enlarged perspective view of the soft X-ray light source according to <FIG>. As shown in <FIG>, the first flange <NUM> and the second flange <NUM> are provided with evenly distributed bolt holes adjacent to the circumferential edge, through which the fastening bolts are inserted to form a tight connection between the first flange <NUM> and the second flange <NUM>. By means of a plurality of first screws <NUM>, the first flange <NUM> is fixedly connected to the third mounting plate <NUM>, such that the latter two are not moveable relative to each other. The first displacement adjuster <NUM> comprises a first bracket <NUM>, a first pusher <NUM>, a first rail <NUM>, and a first rail groove <NUM> (<FIG>). The first bracket <NUM> is in form of an L shape, with one end fastened to the third mounting plate <NUM>, and the other end protruding upwardly and perpendicular to the plane where the third mounting plate <NUM> is located. The first pusher <NUM> is arranged on the other end of the first bracket <NUM> in the X-axis direction and is aligned with the second mounting plate <NUM>, such that the movement of the first pusher <NUM> will drive the second mounting plate <NUM> to move. There are two (<NUM>) first rails <NUM> arranged on the upper surface of the third mounting plate <NUM> and extending along the X-axis direction, and the two first rails <NUM> are arranged symmetrically with respect to the bellows <NUM> and are parallel to each other. The lower surface of the second mounting plate <NUM> is provided with the first rail grooves <NUM> (<FIG>) configured to cooperate with the first rails <NUM>. The first guide rails <NUM> are received in the first guide grooves <NUM> and are slidable along the first guide grooves <NUM>. When the first pusher <NUM> is moved, the second mounting plate <NUM> slides along the first guide rails <NUM> in the X-axis direction. The second displacement adjuster <NUM> comprises a second bracket <NUM>, a second pusher <NUM>, a second rail <NUM>, and a second rail groove. The second bracket <NUM> is in form of an L shape, with one end fastened to the second mounting plate <NUM>, and the other end protruding upwardly and perpendicular to the plane where the first mounting plate <NUM> is located. The second pusher <NUM> is arranged on the other end of the second bracket <NUM> in the Y-axis direction and is aligned with the first mounting plate <NUM>, such that the movement of the second pusher <NUM> will drive the first mounting plate <NUM> to move. There are two (<NUM>) second rails <NUM> arranged on the upper surface of the second mounting plate <NUM> and extending along the Y-axis direction, and the two (<NUM>) second rails <NUM> are arranged symmetrically with respect to the bellows <NUM> and are parallel to each other. The lower surface of the first mounting plate <NUM> is provided with the second rail grooves configured to cooperate with the second rails <NUM>. The second guide rails <NUM> are received in the second guide grooves and are slidable along the second guide grooves. When the second pusher <NUM> is moved, the first mounting plate <NUM> slides along the second guide rails <NUM> in the Y-axis direction. The bellows <NUM> has a cylindrical shape and is configured to be expandable and collapsible in an axial direction thereof, the sealed top portion of the bellows <NUM> is arranged on the lower surface of the mounting plate <NUM>, and the mounting plate <NUM> is fastened on the second screw <NUM> through the adjusting nut <NUM>, such that when the first pusher <NUM> and the second pusher <NUM> are adjusted respectively, the mounting plate <NUM> will be moved along the X-axis direction and the Y-axis direction accordingly, and when the third displacement adjuster <NUM> is adjusted, the mounting plate <NUM> will be moved along the Z-axis direction accordingly.

Further, <FIG> is a schematically, partially cross-sectional perspective view of the soft X-ray light source according to <FIG>. <FIG> is a schematically cross-sectional view of the soft X-ray light source according to <FIG>. <FIG> is a schematically cross-sectional view of the soft X-ray light source according to <FIG>. Referring to <FIG> and <FIG> in combination with <FIG>, the mounting plate <NUM> is also provided with the working gas pipe <NUM>, the refrigerant outlet pipe <NUM>, and the refrigerant inlet pipe <NUM>, which pass through the mounting plate <NUM> from the outside and are inserted into the bellows <NUM>. The refrigeration mechanism comprises a refrigeration cavity <NUM> which may be in form of a cylindrical shape and is received in the vacuum target chamber, a refrigerant inlet pipe <NUM>, and a refrigerant outlet pipe <NUM>. Specifically, the refrigeration cavity <NUM> extends from the inside of the t-branch tube <NUM> into the inside of the multi-channel tube <NUM>, and the refrigerant inlet pipe <NUM> and the refrigerant outlet pipe <NUM> respectively pass from the top of the mounting plate <NUM> through the inside of the bellows <NUM> and through the first flange <NUM> and the second flange <NUM>, and are in turn in communication with and fastened to the top of the refrigeration cavity <NUM>, such that the refrigerant can be delivered from the refrigerant inlet pipe <NUM> into the refrigeration cavity <NUM> to reduce the temperature in the refrigeration cavity <NUM>, while a gas generated in the refrigeration cavity <NUM> is discharged from the refrigeration cavity <NUM> through the refrigerant outlet pipe <NUM>. The working gas pipe <NUM> passes from the top of the mounting plate through the inside of the bellows <NUM>, the first flange <NUM>, the second flange <NUM>, and the refrigeration cavity <NUM>, and after passing through the refrigeration cavity <NUM>, the working gas pipe <NUM> is then connected to the nozzle. The working gas pipe <NUM> has a middle section forming a condensing cavity <NUM> with an enlarged cross-sectional area at least partially located in the refrigeration cavity <NUM>. It should be noted that the inner portion of the working gas pipe <NUM> is not in communication with the inner portion of the refrigeration cavity <NUM>. The working gas, such as nitrogen is delivered to the nozzle through the working gas pipe <NUM> and is liquefied in the process, such that the working gas has been liquefied when outflowing from the nozzle. The water moisture in the working gas is condensed when passing through the condensing cavity <NUM>, such that purity of the proceeding working gas is maintained to prevent the nozzle from being clogged.

<FIG> is a schematically, partially enlarged perspective view of the soft X-ray light source according to <FIG>. As shown in <FIG> in combination with <FIG>, the light-generating mechanism comprises a nozzle <NUM> arranged under the refrigeration cavity <NUM> and fastened thereto by an adapter <NUM>. The nozzle <NUM> is in communication with the working gas pipe <NUM>, such that the working gas that has been condensed into liquid flows out of the nozzle <NUM>. The adapter <NUM> generally is in form of a metal adapter for a rapid and accurate temperature transfer. Arranged at the periphery of the adapter <NUM> is a temperature sensor <NUM> for monitoring the temperature variation surround the nozzle <NUM> in real time, which temperature sensor is connected to an external device by means of one of the plugs <NUM> provided on the top of the mounting plate <NUM>. Arranged below the refrigeration cavity <NUM> is connection piece <NUM> provided with a resistance wire holder <NUM> on which a resistance wire <NUM> is arranged, with a portion of the resistance wire in a form of a spiral surrounding the side face of the nozzle <NUM>. The resistance wire <NUM> is connected to another plug <NUM> provided on the top of the mounting plate <NUM> by means of a conductive wire, to facilitate power supply to the resistance wire. The heating of the resistance wire <NUM> can compensate the temperature drop caused by the evaporation and condensation of the refrigerant liquid, but will not destroy the high-degree vacuum of the surrounding environment of the cryogenic liquid, such that the stability of the micro-liquid flow is further improved, and at the same time, when the nozzle <NUM> is blocked by condensation, the heating of the resistance wire <NUM> will facilitate declogging. Provided below the nozzle, substantially at a distance of <NUM>, is a metal frustum <NUM> which at its top has a groove in communication with a hollowed internal portion of the metal frustum <NUM>, for receiving the residual liquid outflowing from the nozzle <NUM>. The metal frustum <NUM> is designed to timely evacuate the residual liquid that has a great influence on the vacuum degree due to evaporation thereof, so as to reduce the consumption of soft X-rays. The lower part of the metal frustum <NUM> is further connected to the vacuum exhaust port <NUM> by means of a metal adapter <NUM> and a metal connector <NUM>, such that the above-mentioned residual liquid may be drawn out through the vacuum exhaust port <NUM>. It should be noted that the metal adapter <NUM> is also provided with a heat conduction rod <NUM> extending in the Z-axis direction and connected to the refrigeration cavity <NUM> to equilibrate the temperatures of the metal adapter <NUM>, the metal frustum <NUM> and the nozzle <NUM> by means of heat transfer, such that it is assured the residual liquid will not change its state due to temperature variation, which will otherwise reduce the vacuum degree in the vacuum target chamber and affects the brightness of the soft X-rays. Or, the metal adapter <NUM> is provided with a heat conduction tube <NUM> extending in the Z-axis direction and connected to the refrigeration cavity <NUM>, such that the refrigerant in the refrigeration cavity <NUM> can be delivered to the metal adapter <NUM> and the metal frustum <NUM> to equilibrate their temperatures and that in the refrigeration cavity <NUM>, in order to prevent the cryogenic liquid micro-stream from further vaporizing during the flow process, which will otherwise reduce the vacuum degree in the vacuum target chamber and lead to consumption of the soft X-rays.

Since the nozzle <NUM> is fastened to the refrigeration cavity <NUM> which is in turn fastened to the mounting plate <NUM> by the refrigerant inlet pipe <NUM>, the refrigerant outlet pipe <NUM>, and the working gas pipe <NUM>, the multi-axis adjustment of the geometric position of the nozzle <NUM> may be realized by the first displacement adjuster <NUM>, the second displacement adjuster <NUM> and the third displacement adjuster <NUM>, such that the nozzle in the vacuum target chamber may be adjusted in the X-, Y-, and Z-axis directions during the operation of the light source, such that the position of the liquid micro-flow may be controlled and ultimately, the purpose of adjusting the position of the soft X-ray light source may be realized.

<FIG> is a schematic figure of the external device connected to the soft X-ray light source according to <FIG>. As shown in <FIG>, the soft X-ray light source also comprises a refrigerant reservoir <NUM> connected to a refrigerant inlet pipe <NUM> through a delivery pipe <NUM> which is provided with a low-temperature solenoid valve <NUM> for automatically controlling the input of refrigerant and maintain the stable pressure in the refrigeration cavity. The soft X-ray light source further comprises a molecular vacuum pump <NUM> connected to the refrigerant outlet pipe <NUM> through a vacuum delivery tube <NUM> which is provided with a high-temperature buffer cavity <NUM> with a heater <NUM>. Arranged between the high-temperature buffer cavity <NUM> and the molecular vacuum pump <NUM> is a vacuum solenoid valve <NUM>. By heating the extracted low-temperature refrigerant by means of the high-temperature buffer cavity <NUM> and the heater <NUM>, the refrigerant of excessively low temperature is prevented from damaging the vacuum solenoid valve <NUM> and the molecular vacuum pump <NUM>. The vacuum solenoid valve <NUM> may be configured to set a vacuum threshold, so as to be closed when the pressure in the refrigeration cavity is too low and to be opened when the pressure in the refrigeration cavity is too high, such that the control of the temperature in the refrigeration cavity may be realized. The refrigerant within the refrigeration cavity <NUM> may be circulated and replaced by means of the molecular vacuum pump <NUM>, such that a relatively low refrigeration temperature may be realized at the nozzle and can be precisely adjusted with a higher refrigeration efficiency, such that certain gases with an extremely low liquefaction point, such as nitrogen may be liquefied, and a more stable spray with a longer spray distance may be achieved, such that the soft X-ray light source is more stable and is applicable to various types of gas targets. The multi-channel tube <NUM> is also provided with a vacuum gauge interface <NUM> on the side face thereof, and a vacuum gauge is connected to the multi-channel tube <NUM> through the vacuum gauge interface <NUM> to measure the vacuum degree within the multi-channel tube <NUM>. The light-generating mechanism also comprises a high-energy laser pulse generator with an entrance arranged at one of the exits on the side face of the multi-channel tube <NUM>. Arranged over the exit is a laser focusing lens <NUM> for allowing the high-energy laser pulses <NUM> to be focused at the nozzle <NUM> within the multi-channel tube <NUM> and impact on the liquid micro-flow, such that the liquid micro-flow is plasmonized and soft X-rays are generated. In order to maintain the vacuum degree in the multi-channel tube <NUM> and the t-branch tube <NUM>, the third flange <NUM> on the t-branch tube <NUM> and the vacuum exhaust port <NUM> at the bottom of the multi-channel tube <NUM> are connected to a vacuum extraction device. Considering that the vacuum extraction outlets are respectively located at the upper and lower ends of the vacuum target chamber, such that the vacuum degree in the vacuum target chamber can be maintained at a high level.

It should be noted by those skilled in the art that the first displacement adjuster and the second displacement adjuster mentioned in the technical solutions in the present application may be micrometer heads, and the third displacement adjuster may be replaced by other stepping devices, that is, any adjustment devices capable of manual or automatic adjustment of linear displacement with micron accuracy, such as an electric displacement table, which fall within the scope of the invention. It should be noted by those skilled in the art that the nozzle may be made of low-temperature resistant glass nozzles, and the adapter components, the adapters, and the metal frustum may be made of low-temperature resistant metal materials. The high-energy laser pulse may be generated by a high-energy nanosecond pulse laser device or may be generated by other high-energy short-pulse laser light sources, such as a femtosecond pulse laser device or the like, which will not be elaborated here. The vacuum pump in the disclosure may be selected from any of the ion pump, the roots pump, and the like, so as to achieve high-degree vacuum in the vacuum target chamber. The working gas is preferably nitrogen. However, nitrogen is only one of the target substances for generating laser plasma. Any other substance, including gas or liquid, which is able to generate laser plasma that radiates soft X-rays of a certain intensity, such as alcohol, xenon, and other substances, will fall within the scope of the invention.

Claim 1:
A soft X-ray light source, comprising a vacuum target chamber, a refrigeration cavity (<NUM>), and a nozzle (<NUM>), wherein the refrigeration cavity (<NUM>) and the nozzle (<NUM>)are received in the vacuum target chamber, and the nozzle (<NUM>) is fastened to the refrigeration cavity (<NUM>), characterized in that the vacuum target chamber comprises:
a t-branch tube (<NUM>), having a first outlet and a second outlet opposed to each other as well as a third outlet located between the first outlet and the second outlet, wherein the first outlet is connected to a mounting plate (<NUM>) through which a refrigerant inlet pipe (<NUM>), a refrigerant outlet pipe (<NUM>), and a working gas pipe (<NUM>) respectively pass and are connected to the refrigeration cavity (<NUM>), and wherein the third outlet is connected to a vacuum extraction device; and
a multi-channel tube (<NUM>), comprising a top opening and a bottom opening opposed to each other as well as a plurality of side openings located between the top opening and the bottom opening, wherein the top opening is tightly connected to the second outlet, wherein a vacuum outlet is provided at the bottom opening, wherein the nozzle (<NUM>) has a position corresponding to positions of the side openings such as to allow a high-energy laser to be focused at the nozzle, wherein provided under the nozzle (<NUM>) is a groove of a groove member which is fixed by a first adapter (<NUM>) arranged at the vacuum outlet, and wherein the groove is for receiving a liquid outflowing from the nozzle and is in communication with the vacuum outlet.