TW201515057A - Excimer lamp and method for producing same - Google Patents

Abstract

Provided is an excimer lamp that prevents damage to an inner tube caused by the difference in thermal expansion coefficient between an inner electrode and the inner tube. The excimer lamp is equipped with: a luminescent tube which has a bottomed cylindrical inner tube, and an outer tube forming a sealed discharge space together with the inner tube, and comprises a dielectric with a discharge gas enclosed in the discharge space; an outer electrode which is disposed on the outer peripheral surface side of the outer tube of the luminescent tube; and an inner electrode which is inserted into the inner tube. With the excimer lamp, stress exerted on the inner tube by the inner electrode when the inner electrode thermally expands due to dielectric barrier discharge between the inner peripheral surface of the inner tube and the outer peripheral surface of the inner electrode is suppressed, and a buffer space having a cross-sectional area which ensures dielectric barrier discharge in the discharge space is formed taking into consideration the size of the discharge space and the size of the discharge voltage.

Description

Excimer lamp and manufacturing method thereof

The present invention relates to an excimer lamp that uses a dielectric barrier discharge or a capacity-coupled high-frequency discharge to discharge light and a method of manufacturing the same.

The excimer lamp is a light-emitting tube having a sealed discharge space formed of a dielectric material such as quartz or ceramic that allows excimer light to pass through, and a rare gas such as xenon or a rare gas or a halogen gas is mixed. The resulting mixed gas is sealed in the discharge space as a discharge gas. When a high voltage of several kV is applied between the internal electrode and the external electrode disposed inside and outside the discharge space, a dielectric barrier discharge or a capacity-coupled high-frequency discharge is generated in the discharge space (hereinafter referred to as a dielectric barrier discharge) The excimer light is emitted to the outside of the arc tube (for example, refer to Patent Document 1).

Large excimer lamps have considerable degrees of freedom in the shape or configuration of their tubes or electrodes. On the other hand, the small excimer lamp developed by the applicant of the present invention has a diameter of 8 to 20 (mm), and a sealed discharge space is formed between the inner tube having a bottomed cylindrical shape and the inner tube. The outer tube constitutes an arc tube, and the discharge gas is sealed in the discharge space. Further, a high voltage (hereinafter referred to as an applied voltage) is applied between the outer electrode disposed on the outer peripheral surface side of the outer tube of the arc tube and the inner electrode disposed in the inner tube, thereby generating a dielectric in the discharge space. The electrical barrier discharges. An excimer lamp of such a configuration, the light-emitting tube of which is composed of an outer tube and a bottomed tube Since the inner tube is formed, it has an advantage that the arc tube is easy to manufacture, and since the inner electrode is rod-shaped (columnar) inserted into the inner tube, there is an advantage that the electrode fabrication and the fixing of the electrode and the lamp are easy.

[Advanced technical literature]

Patent Document 1: Japanese Patent Laid-Open No. Hei 6-275242

Patent Document 2: Japanese Laid-Open Patent Publication No. 2013-69533

However, in an excimer lamp, an applied voltage is applied between the electrodes, and when a dielectric barrier discharge is generated in the discharge space (the excimer lamp is lit), the electrode is heated (or overheated). In particular, when the inner electrode is in the form of a rod (for example, a columnar shape) as described above, a radial stress is applied to the inner tube due to thermal expansion of the heated inner electrode, which may be caused by the influence of the stress. The tube is distorted and the inner tube is damaged. With regard to Patent Document 2 of the applicant's application, it is taught to ensure a space between the inner electrode and the inner tube so that a corona discharge is generated between the inner electrode and the inner tube, but the contact between the two is not recognized at all. The problem caused.

The present invention is based on the above-described problem of the excimer lamp (especially a small excimer lamp), and aims to provide a small excimer lamp and a method of manufacturing the same, which is not caused by the difference in thermal expansion coefficients of the inner electrode and the inner tube. The inner tube is broken and the ultraviolet rays can be efficiently emitted.

The excimer lamp of the present invention is characterized by comprising: an arc tube having a bottomed cylindrical inner tube and a sealed discharge space formed between the inner tube and the inner tube The outer tube is composed of a dielectric material that encloses the discharge gas in the discharge space; the outer electrode is disposed on the outer peripheral surface side of the outer tube of the arc tube; and the inner electrode is inserted into the inner tube; Applying a discharge voltage between the outer electrode and the inner electrode to cause a dielectric barrier discharge or a capacity-coupled high-frequency discharge excimer lamp in the discharge space, wherein the inner circumference of the inner tube Between the outer peripheral surface of the surface and the inner electrode, when the dielectric barrier discharge or the capacity-coupled high-frequency discharge causes the inner electrode to thermally expand, the inner electrode is restrained from stressing the inner tube, and the size of the discharge space is considered and The magnitude of the discharge voltage forms a buffer space that ensures a cross-sectional area of dielectric barrier discharge or capacity-coupled high-frequency discharge in the discharge space.

In a preferred embodiment of the excimer lamp of the present invention, the end portion on the opposite side of the bottom portion of the inner tube and the gap interposed between the inner electrode of the inner tube are sealed by the holding portion, and the inner tube is A shaft end space communicating with the buffer space is formed between the bottom inner surface and the front end portion of the inner electrode.

The cross-sectional area of the buffer space perpendicular to the axis of the arc tube is the range of the following formula: 0.05 × G ≦ H ≦ 0.1932 × V × J; the above H represents the sectional area (mm ² ) of the buffer space, and G represents the section of the inner electrode Area (mm ² ), V represents an applied voltage (kV), and J represents a sectional area (mm ² ) of the discharge space.

The bottom and outer tubes of the inner tube can be brought into contact with each other.

Specifically, the excimer lamp of the present invention is suitable for an excimer lamp having an outer diameter of 8 to 20 mm and an applied voltage between the outer electrode and the inner electrode of 2 to 8 kV.

The aspect of the method for producing an excimer lamp of the present invention is characterized by comprising: preparing a tubular outer tube composed of a dielectric having at least one end open a step of preparing a bottomed cylindrical inner tube material composed of a dielectric material; and a step of inserting the inner tube material from the one end opening portion of the outer tube material with the bottom of the inner tube material as a front side; Forming a discharge space between the outer tube material and the inner tube material, sealing a discharge gas into the discharge space, and sealing the discharge space; and forming a buffer space between the inner peripheral surface and the inner tube material The inner electrode of the outer diameter is inserted into the inner tube material, and the outer electrode is placed on the outer peripheral surface of the outer tube material.

In a preferred aspect of the manufacturing method, the method further includes the step of sealing the gap between the end portion on the opposite side of the bottom of the inner tube material and the inner electrode.

According to the present invention, in the small excimer lamp, the arc tube is not damaged by the thermal expansion of the inner electrode, and the generation of the dielectric barrier discharge in the discharge space can be ensured, and the ultraviolet ray can be efficiently emitted.

10‧‧‧Small excimer lamp

20‧‧‧Light tube

30‧‧‧Outer electrode

31‧‧‧Inside electrode

32‧‧‧The inner surface of the inner electrode

40‧‧‧External management

40X‧‧‧External material

42‧‧‧Bottom of the outer tube

43‧‧‧Exhaust pipe

44‧‧‧End of the outer tube

50‧‧‧Inside

50X‧‧‧Inner material

51‧‧‧ inner tube inner circumference

52‧‧‧ bottom of the inner tube

53‧‧‧Contact portion of the inner circumferential surface of the inner tube and the outer peripheral surface of the inner electrode

60‧‧‧discharge space

70‧‧‧ buffer space

71‧‧‧Axis end space (buffer space)

80‧‧‧ Holding Department

81‧‧‧AC power supply department

Fig. 1 is a cross-sectional view showing the first embodiment of the excimer lamp of the present invention, which is an axis passing through an excimer lamp.

Fig. 2 is a cross-sectional view taken along line II-II of Fig. 1.

Fig. 3 is an enlarged sectional view showing a portion III of Fig. 1.

Fig. 4 is a cross-sectional view corresponding to Fig. 1 showing a second embodiment of the excimer lamp of the present invention.

Fig. 5 is a cross-sectional view taken along line V-V of Fig. 4.

Fig. 6 (A) to (D) are cross-sectional views showing an embodiment of a method for producing an excimer lamp of the present invention.

Fig. 7 is a graph showing experimental results showing the relationship between the sectional area of the buffer space of the excimer lamp of the present invention, the sectional area of the discharge space, the applied voltage, and the amount of ultraviolet radiation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The excimer lamp described in Patent Document 2 is a lamp for generating ozone, which introduces the atmosphere around the inner electrode and generates a corona discharge between the inner electrode and the arc tube. However, in this embodiment, ultraviolet radiation is suppressed. The damaged device of the lamp does not generate ozone, but only effectively uses ultraviolet rays discharged by the dielectric barrier.

Fig. 1 to Fig. 3 show a first embodiment of the small excimer lamp 10 of the present invention.

The small excimer lamp 10 is a discharge lamp including an arc tube 20 made of a translucent dielectric such as quartz glass or ceramics, an outer electrode 30, and a columnar inner electrode 31 which is provided for ultraviolet rays. A device such as irradiation. The diameter of the arc tube 20 (outer tube 40) of the present embodiment is 8 to 20 (mm).

In the arc tube 20, a sealed space (hereinafter referred to as a discharge space) 60 is provided between the outer tube 40 and the inner tube 50 disposed in the outer tube 40. In this embodiment, the outer tube 40 and the inner tube 50 are both in the shape of a bottomed cylindrical tube (slightly U-shaped in cross section), and one end (the right end of the first drawing) has a closed bottom portion 42 and a bottom portion 52. The bottom 52 is in contact with each other. The other end portion 41 of the outer tube 40 and the outer peripheral portion of the inner tube 50 are integrally coupled (melted and integrated), and a doughnut-shaped discharge space is formed between the outer tube 40 and the outer tube 50. 60. A rare gas such as Xe or a mixed gas of a rare gas and a halogen gas is sealed in the discharge space 60 as a discharge gas. In addition, the bottom 52 of the inner tube 50 and the bottom 42 of the outer tube 40 They can also be out of contact with each other.

In the illustrated example, the outer tube 40 and the inner tube 50 have a concentric shape as shown in Fig. 2, but may have a non-circular cross section such as a circular shape, as long as it can form a seal between the two. The shape of the discharge space 60 is sufficient.

The outer electrode 30 is disposed along the outer peripheral surface of the outer tube 40, and is, for example, a strip shape, a film shape, or a line shape, so that excimer light emitted from the discharge space is transmitted or reflected to the outside. Further, the side electrode 30 may be in close contact with the outer peripheral surface of the outer tube 40 or may be separated by a predetermined distance. Further, the outer electrode 30 may be provided on at least a portion of the outer peripheral surface of the outer tube 40.

The inner electrode 31 is, for example, a columnar shape having a diameter in the range of 0.7 to 4.0 (mm).

On the other hand, as shown in FIG. 3, the inner electrode 31 is disposed inside the inner tube 50 coaxially inside the bottom portion 52 of the inner tube 50. In the illustrated embodiment, a tapered surface 50T whose diameter gradually decreases toward the distal end is formed in the inner tube 50, and the distal end outer circumference 31R of the cylindrical inner electrode 31 abuts against the tapered surface 50T, whereby the inner electrode 31 is coaxial It is disposed in the inner tube 50 in a shape. The end portion on the opposite side of the bottom portion 52 of the inner tube 50 and the inner electrode 31 are integrally held by the retaining portion 80 of the annular space interposed therebetween, on the outer peripheral surface 32 of the inner electrode 31 and the inner tube 50. A buffer space 70 concentric with the inner tube 50 is formed between the inner peripheral faces 51. Further, between the tip end portion of the inner electrode 31 and the bottom portion 52 of the inner tube 50, a shaft end space 71 communicating with the buffer space 70 is formed. The holding portion 80 may be composed of an adhesive or a shrink tube. In addition, the inner electrode 31 and the inner tube 50 may be disposed coaxially by the holding portion 80 without the contact relationship between the distal end outer edge 31R of the inner electrode 31 and the tapered surface 50T.

The outer electrode 30 and the inner electrode 31 are connected to the alternating current power supply unit 81. When a high-frequency high voltage of several kV is applied as an applied voltage through the AC power supply unit 81 to be applied between the outer electrode 30 and the inner electrode 31, a dielectric barrier is generated between the outer tube 40 as the dielectric and the inner tube 50. Discharge. Since a rare gas or a mixed gas of a rare gas and a halogen is sealed in the discharge space 60 as a discharge gas, ultraviolet light is generated in the discharge space 60 by dielectric barrier discharge, that is, corresponding to the wavelengths of the rare gas and the halogen. Light. As a result, ultraviolet light is emitted from the arc tube. Further, in the present embodiment, the generation of ozone and the accompanying release of ozone are not required. Therefore, the buffer space 70 can be sealed by, for example, the holding portion 80 to prevent the ozone generated in the buffer space 70 from being released. Further, for example, an inert gas or the like may be enclosed so that oxygen is not contained in the sealed buffer space 70 to prevent the occurrence of ozone.

The size (sectional area) of the buffer space 70 is determined in the manner described below.

First, when the size of the buffer space 70 is 0 (that is, the inner electrode 31 and the inner peripheral surface 51 of the inner tube 50 are in close contact with each other), the inner tube 50 (i.e., the arc tube 20) is damaged. When the excimer lamp is turned on, the temperature of the inner electrode 31 sometimes rises to several hundred degrees, and the outer diameter of the inner electrode 31 and the inner diameter of the inner tube 50 are almost the same, and the outer peripheral surface 32 of the inner electrode 31 and the inner tube 50 are When the inner peripheral surface 51 is in close contact, the inner tube 50 is subjected to a radial stress due to thermal expansion of the inner electrode 31. This stress concentrates, for example, on the bottom 52 of the inner tube 50, which may be one of the causes of damage to the excimer lamp. For example, when the inner electrode 31 is made of a columnar metal and the arc tube 20 is made of quartz glass, the linear expansion coefficient of both is larger by the inner electrode 31.

In the present embodiment, the minimum cross-sectional area (buffer space sectional area lower limit value Hmin) of the buffer space 70 is set such that the thermal expansion of the inner electrode 31 as described above does not occur in the inner tube 50. Stress concentration. this The inventors have learned from experience that the relationship between the sectional area H of the buffer space 70 and the sectional area G of the inner electrode 31 in the cross section of the lamp diameter direction can be determined in the range of the applied voltage of 2 to 8 (kV). The lower limit of the sectional area of the buffer space in which the inner tube 50 is broken is generated. Specifically, it can be known that when the applied voltage is 2 to 8 (kV), the buffer space sectional area lower limit value (Hmin) can be obtained by the following formula (1).

(1)Hmin=0.05×G

Here, Hmin represents the lower limit value (mm ² ) of the sectional area of the buffer space, and G represents the sectional area (mm ² ) of the inner electrode.

On the other hand, the maximum cross-sectional area (buffer space sectional area upper limit value Hmax) of the buffer space 70 is between the outer electrode 30 and the inner electrode 31 in accordance with the sectional area of the inner electrode 31, the sectional area of the discharge space 60, and The applied voltage ensures the cross-sectional area of the dielectric barrier discharge in the discharge space 60. In other words, this maximum sectional area is a sectional area of the dielectric barrier discharge in the discharge space 60 (the accompanying decrease in the amount of ultraviolet radiation) caused by the presence of the suppression buffer space 70. In the excimer lamp, if the outer peripheral surface 32 of the inner electrode 31 does not contact the inner peripheral surface 51 of the inner tube 50, the electrostatic capacitance in the radial direction becomes small and the electric field also becomes weak. When the electric field becomes weak, the dielectric barrier discharge is reduced, and the amount of ultraviolet radiation is also reduced. Further, when an applied voltage is applied, a significant unequal electric field is sometimes generated between the inner electrode 31 and the inner tube 50, and a flow photo-wave discharge is generated in the buffer space 70. When the flow photo-foam discharge occurs, the dielectric barrier discharge in the discharge space 60 is hindered, so that the amount of ultraviolet radiation is reduced.

The inventors of the present invention have learned from experience that the amount of reduction in the amount of ultraviolet radiation varies depending on the size of the discharge space in which the dielectric barrier discharge occurs, the size of the buffer space that hinders the discharge of the dielectric barrier, and the magnitude of the applied voltage. ; And, when the applied voltage V is 2 to 8 (kV), the maximum value of the sectional area of the buffer space 70 (the buffer space sectional upper limit Hmax) which deliberately prevents the dielectric barrier discharge in the discharge space 60 from being reduced is It is obtained by the following formula (2).

(2) Hmax = 0.1932 × V × J

Here, Hmax represents the upper limit value (mm ² ) of the sectional area of the buffer space, J represents the sectional area (mm ² ) of the discharge space, and V represents the applied voltage (kV).

Further, in the embodiment of Figs. 1 to 3, an end space 71 is formed between the tip end portion of the inner electrode 31 and the bottom portion 52 of the inner tube 50. When the end space 71 is formed in this manner, it is possible to suppress the axial stress caused by the thermal expansion of the inner electrode 31 received by the inner tube bottom portion 52. Further, by providing the end space 71 with the inner tube bottom portion 52 which tends to concentrate the stress in the direction of the lamp diameter, it is possible to withstand the stress in the lamp diameter direction, and furthermore, the buffer space 70 can be further prevented. Damage to the inner tube. Further, in a state in which the end space 71 is omitted (the inner electrode 31 and the inner tube bottom 52 are in close contact with each other), or vice versa, the front end portion of the inner electrode 31 and the bottom portion 52 of the inner tube 50 may be completely separated.

Fig. 4 and Fig. 5 show a second embodiment of the compact excimer lamp 10 of the present invention.

In this embodiment, the axis of the inner tube 50 does not coincide with the axis of the columnar inner electrode 31, and the inner electrode 31 is disposed to be biased toward the inner diameter of the inner tube 50. That is, the outer peripheral surface 32 of the inner electrode 31 is in contact with a portion 53 of the inner peripheral surface 51 of the inner tube 50, and the buffer space 70 between the inner peripheral surface 51 of the inner tube 50 and the outer peripheral surface 32 of the inner electrode 31 is not in contact with The tube 50 (inner electrode 31) is coaxial. Further, the tip end portion of the inner electrode 31 and the bottom portion 52 of the inner tube 50 are not in contact.

When the small excimer lamp 10 of the second embodiment is turned on, The inner surface 53 where the side electrode 31 is in contact is affected by the thermal expansion stress of the inner electrode 31, but the inner electrode 31 moves in the direction of the buffer space 70 due to thermal expansion. The cushioning (elasticity) holding portion 80 makes it possible to move the inner electrode 31. Therefore, even if the inner electrode 31 and the inner surface 53 are in contact, there is no problem as long as there is a buffer space having a predetermined sectional area. Further, in the embodiments of FIGS. 4 and 5, the axis of the inner electrode 31 and the axis of the inner tube 50 are parallel, but they may not be parallel, and a buffer space 70 may be formed therebetween.

As described above, even if the axis of the inner electrode 31 does not coincide with the axis of the inner tube 50, there is no substantial adverse effect on the discharge luminescence. That is, when the axis of the inner electrode 31 and the axis of the inner tube 50 do not coincide, the distance between the inner electrode 31 and the outer electrode 30 is not uniform in the lamp circumferential direction, and the radial capacitance is also uneven along the circumferential direction. Case. In a portion where the electrostatic capacity is relatively large, the electric field is usually relatively strong, thereby generating a dielectric barrier discharge. Therefore, the electric charge accumulated in the other electrode portion having a relatively small electrostatic capacitance moves toward the inter-electrode portion where the dielectric barrier discharge is generated. As a result, a dielectric barrier discharge is generated in a specific spatial domain within the discharge space 60. The ultraviolet radiation emits light around the discharge generation position, and the electric charge accumulated between the entire electrodes by the application of the applied voltage is directly and effectively utilized for the dielectric barrier discharge, so that ultraviolet light having a light intensity can be obtained. Such an excimer lamp can emit light with sufficient intensity by defining its radiation direction when the supplied electric power is small.

Fig. 6 is a view showing an embodiment of a method for producing an excimer lamp of the present invention.

As shown in Fig. 6(A), the inner tube material 50X made of a dielectric material is a bottomed cylindrical material closed by the tip end bottom 52, and an outer tube which is also composed of a dielectric material. The material 40X is a cylindrical material in which the one end opening portion 44 is open and the other end portion has a small diameter exhaust portion 43. The inner tube material 50X is inserted into the outer tube material 40X from the one end opening portion 44 with the tip end bottom portion 52 as the front side, and the bottom portion 52 is located in the vicinity of the exhaust portion 43.

In this state, the one end opening portion 44 of the outer tube material 40X is heated and melted so as to be welded to the outer circumference of the inner tube material 50X, and is configured to be connected to the one end connecting portion 41 of the outer tube 40 (Fig. (B)). Then, the air (gas) which is the space of the discharge space 60 is exhausted from the exhaust portion 43, and the discharge gas is sealed in the discharge space 60 (after replacing the air in the discharge space 60 with the discharge gas), The exhaust portion 43 is softened and melted (fused) to form the bottom portion 52. The bottom portion 52 is in contact with the bottom portion 42 of the inner tube material 50X (the inner tube 50) (Fig. (C)).

Then, the rod-shaped inner electrode 31 is inserted into the inner tube material 50X, and the tip end portion thereof is brought into contact with the bottom portion 42, and the inner tube material 50X and the inner side of the end portion on the opposite side of the bottom portion 42 are held by the sealing member (holding material) 80. An annular gap between the electrodes 31. Alternatively, the buffer space 70 may be sealed (the same figure (D)). The outer diameter of the inner electrode 31 is an outer diameter of the buffer space 70 having the above-described size (sectional area) formed between the inner tube surface 51 and the inner circumferential surface 51 of the inner tube material 50X. Further, the outer electrode 30 is disposed outside the outer tube 40 (the same figure (D)).

The exhaust portion 43 of the outer tube material 40X may be formed as a hole instead of being formed in a coaxial cylindrical shape.

In the present excimer lamp 10, the emission wavelength can be changed by selecting the gas enclosed in the discharge space 60. For example, a mixed gas of argon and fluorine may be enclosed to emit light having a wavelength of 193 nm. In addition, the embrittlement protection of the glass of the outer tube material 40X and the inner tube material 50X, and the prevention of the glass and the enclosed gas are reversed. A protective film such as an aluminum oxide film, a titanium oxide film, or a magnesium oxide film can be formed on the outer tube and the inner tube. When the enclosed gas contains a halogen, a magnesium fluoride film can be formed.

[Examples]

The discharge excimer lamp 10 satisfying the above formula (1) will be described below using an embodiment.

In the experiment, the cross-sectional area of the buffer space 70 in the axial cross section of the excimer lamp 10 was changed with respect to the sectional area of the inner electrode 31, and the inner tube 50 was measured for damage by lighting. A specific example of the experiment will be described.

The cross-sectional area of the inner electrode 31 is 3.14 (mm ² ) (radius 1 mm, constant), and the excimer lamp of the arc tube 20 having the cross-sectional area of the buffer space 70 varying from 0.04 to 0.21 (mm ² ) is taken as the sample group 1 ~6, apply a voltage of 2~8 (kV) to make it light, and observe whether the inner tube 50 is damaged. Table 1 below is the result.

Table 1 based on the cross-sectional area (mm ²⁾ of the buffer space 70 is a cross-sectional area of the inner electrode 31 (mm ²⁾ of samples 1 to about 4%, we found damaged tube 50, whereas the same cross-sectional area ratio exceeds 5 The inner tube 50 of % of samples 2 to 6 was not damaged. That is, it can be known that the correlation between the sectional area (mm ² ) of the buffer space 70 in which the inner tube 50 is not damaged and the sectional area (mm ² ) of the inner electrode 31 is the sectional area of the buffer space 70 (mm ^{2 ).} The cross-sectional area (mm ² ) of the inner electrode 31 is 5% or more. Further, when the cross-sectional area of the inner electrode 70 is between 0.38 and 12.5 (mm ² ), the correlation between the cross-sectional area (mm ² ) of the buffer space 70 and the cross-sectional area (mm ² ) of the inner electrode 31 is also derived. result.

Next, a discharge excimer lamp satisfying the above formula (2) will be described using an embodiment.

When the discharge space 60 becomes large, the size of the cross-sectional area H of the buffer space 70 that ensures the emission of ultraviolet rays in the discharge space 60 is also relatively large. In addition, since the amount of ultraviolet radiation is also increased when the applied voltage is increased, it can be inferred that the cross-sectional area H of the buffer space 70 is relatively large. Here, an experiment for measuring the amount of decrease in the amount of ultraviolet radiation in the case where the applied voltage V (kV), the sectional area H (mm ² ) of the buffer space 70, and the sectional area J (mm ² ) of the discharge space 60 are respectively changed is performed.

An excimer lamp was prepared as an experimental sample (experimental excimer lamp), which made the cross-sectional area G of the inner electrode 31 constant, and changed the sectional area H (mm ² ) of the buffer space 70, the applied voltage V (kV), And the sectional area J (mm ² ) of the discharge space 60, and the amount of ultraviolet radiation of each excimer lamp was measured. Further, a comparison of the excimer lamp was made as a comparison of the ultraviolet radiation amount of each of the above experimental excimer lamps, and the sectional area J of the applied voltage V and the discharge space 60 was the same as that of each of the experimental excimer lamps, and only the buffer space 70 was made. The sectional area H is the lower limit of the sectional area of the buffer space, and the amount of ultraviolet radiation is measured, and the ultraviolet radiation amount of each experimental excimer lamp and the ultraviolet radiation amount of the comparative excimer lamp are respectively compared. The experimental results when the cross-sectional area G of the inner electrode 31 is 12.57 (mm2) are shown in Fig. 7 as a specific example.

As can be seen from Fig. 7, the maximum value (the buffer space sectional area upper limit value; Hmax) of the sectional area H of the buffer space 60 capable of suppressing the decrease in the amount of ultraviolet radiation can be obtained by the equation (2). Further, when the cross-sectional area G of the inner electrode 31 is 0.3 to 13 (mm ² ), the applied voltage V is 2 to 8 (kV), and the sectional area J of the discharge space 60 is in the range of 8.5 to 300.5 (mm ² ), The correlation between the buffer space sectional upper limit value Hmax, the sectional area G of the inner electrode 31, the applied voltage V, and the sectional area J of the discharge space 60 is also derived almost identically.

10‧‧‧Small excimer lamp

20‧‧‧Light tube

30‧‧‧Outer electrode

31‧‧‧Inside electrode

32‧‧‧The inner surface of the inner electrode

40‧‧‧External management

42‧‧‧Bottom of the outer tube

43‧‧‧Exhaust pipe

44‧‧‧End of the outer tube

50‧‧‧Inside

51‧‧‧ inner tube inner circumference

52‧‧‧ bottom of the inner tube

60‧‧‧discharge space

70‧‧‧ buffer space

71‧‧‧Axis end space (buffer space)

80‧‧‧ Holding Department

81‧‧‧AC power supply department

Claims (7)

An excimer lamp comprising: an arc tube having a bottomed cylindrical inner tube; and a tube forming a sealed discharge space between the inner tube and the inner tube, the discharge gas being enclosed in the discharge space a dielectric material; an outer electrode disposed on an outer peripheral surface side of the outer tube of the arc tube; and an inner electrode interposed in the inner tube; and applying a discharge voltage between the outer electrode and the inner electrode Thereby, an excimer lamp for causing a dielectric barrier discharge or a capacity-coupled high-frequency discharge in the discharge space, wherein between the inner peripheral surface of the inner tube and the outer peripheral surface of the inner electrode, When the electric barrier discharge or the capacity-coupled high-frequency discharge causes the inner electrode to thermally expand, the inner electrode is restrained from applying stress to the inner tube, and the size of the discharge space and the magnitude of the discharge voltage are determined to be ensured in the discharge space. The buffer space of the cross-sectional area of the dielectric barrier discharge or the capacity combined high-frequency discharge. The excimer lamp of claim 1, wherein the end portion of the opposite side of the bottom portion of the inner tube and the gap between the inner electrode of the inner tube are sealed by the holding portion, A shaft end space communicating with the buffer space is formed between the inner surface of the bottom of the tube and the tip end portion of the inner electrode. The excimer lamp according to claim 1 or 2, wherein: the cross-sectional area of the buffer space perpendicular to the axis of the arc tube is a range of the following formula: 0.05 × G ≦ H ≦ 0.1932 × V × J; H represents a sectional area (mm ² ) of the buffer space, G represents a sectional area (mm ² ) of the inner electrode, V represents an applied voltage (kV), and J represents a sectional area (mm ² ) of the discharge space. The excimer lamp of any one of claims 1 to 3, wherein the bottom of the inner tube and the outer tube are in contact with each other. The excimer lamp according to any one of claims 1 to 4, wherein the outer tube has an outer diameter of 8 to 20 mm, and an applied voltage between the outer electrode and the inner electrode is 2 to 8 kV. A method for producing an excimer lamp, comprising: preparing a tubular outer tube material having at least one end open dielectric material; and preparing a bottomed cylindrical inner tube material having a dielectric material; a step of inserting the inner tube material from the one end opening portion of the outer tube material with the bottom of the inner tube material as a front portion; forming a discharge space between the outer tube material and the inner tube material to seal the discharge gas into the discharge a step of sealing the discharge space in the space; and inserting an inner electrode having an outer diameter forming a buffer space with an inner circumferential surface of the inner tube material in the inner tube material, and disposing the outer electrode in the space The step of the outer peripheral surface of the outer tube material. The method for producing an excimer lamp according to claim 6, further comprising the step of sealing a gap between the end portion on the opposite side of the inner tube material and the inner electrode.