JPH0887989A - Dielectric barrier discharge lamp - Google Patents

Abstract

(57) [Summary] [Object] To provide a dielectric barrier discharge lamp that emits vacuum ultraviolet light having a wide half-width of the emission spectrum. [Arrangement] The discharge vessel is filled with a discharge gas that forms excimer molecules by dielectric barrier discharge, and a mixed gas of xenon and krypton is used as the discharge gas, and the atomic ratio of xenon / krypton is 0.01 to 0. Enclose within the range of 1.

Description

Detailed Description of the Invention

[0001]

The present invention relates to, for example, spectroscopic measurement,
The present invention relates to improvement of a dielectric barrier discharge lamp used as a vacuum ultraviolet light source for photochemical reaction.

[0002]

2. Description of the Related Art As a technique related to the present invention, there is, for example, Japanese Patent Laid-Open Publication No. 2-7353, in which a discharge vessel is filled with a discharge gas for forming excimer molecules, and a dielectric barrier. Discharge (also known as ozonizer discharge or silent discharge. Revised new edition "Discharge Handbook" published by the Institute of Electrical Engineers of Japan
This paper describes a radiator, that is, a dielectric barrier discharge lamp that causes excimer molecules to be formed by the issue of Resale 7th Printing, June 1993, see page 263), and the light emitted from the excimer molecules is extracted. The above-mentioned dielectric barrier discharge lamp is useful because it has various features that conventional low-pressure mercury discharge lamps and high-pressure arc discharge lamps do not have. In particular, a dielectric barrier discharge lamp using xenon or krypton as a discharge gas has a feature of efficiently emitting vacuum ultraviolet light. The excimer light of krypton has a wavelength of 146 nm, and the excimer light of xenon has a wavelength of 17 nm.
The full width at half maximum at 2 nm is about 13 nm to 14 nm. These matters are reported in the 41st Joint Lecture on Applied Physics, 30P-ZE-3 (1994). However, it has a drawback that the half width is narrow when it is used as a standard light source for vacuum ultraviolet light, a light source for measuring substance absorption characteristics in the vacuum ultraviolet region, and the like.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned drawbacks, and its purpose is to have radiated light in the vacuum ultraviolet region and to have high efficiency with a wide wavelength width of the radiated light. It is to provide a light source.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to fill a discharge vessel with a discharge gas for forming excimer molecules by dielectric barrier discharge in the lamp, wherein the discharge gas is a mixture of xenon and krypton. It is a gas, and it is achieved by defining the ratio of xenon / krypton in the atomic ratio of 0.01 to 0.1.

[0005]

As a result of intensive studies, it has been found that the wavelength width can be increased by mixing xenon and krypton. At that time, it was discovered that the amount of xenon had to be made smaller than that of krypton to be 0.1 or less. Even if the amount of xenon is small, from excited krypton atoms to xenon atoms, or because energy transition from krypton excimer to xenon atoms occurs, the density of excited xenon atoms increases, the excited xenon atoms are ground state xenon atoms, Alternatively, a triple collision with a krypton atom occurs to generate xenon excimer, and as a result, the intensity of xenon excimer light becomes high. There is no energy transition from the opposite excited xenon atom to the krypton atom. Therefore, even if the mixing ratio of the xenon gas is small, the intensity of the xenon excimer light becomes high. The xenon excimer appears even when xenon / krypton is 0.002, but the wavelength of 147 nm is absorbed by the absorption of the resonance line of the xenon atom, and as a result, the full width at half maximum of the emitted light is not widened. The atomic ratio increases from 0.01 to the half value width. On the contrary, when the atomic ratio exceeds 0.1 and xenon is added, the krypton excimer decreases, and the spectrum approaches that of pure xenon excimer light, so that the full width at half maximum cannot be expected.

[0006]

1 is a schematic explanatory view of a dielectric barrier discharge lamp which is an embodiment of the present invention. The hollow cylindrical discharge vessel 8 is made of synthetic quartz glass having a total length of about 150 mm, an inner tube 9 having an outer diameter of 14 mm and a wall thickness of 1 mm, and an inner tube having a wall thickness of 1 mm of about 2 mm.
The outer tube 10 of 5 mm is coaxially arranged to form a hollow cylindrical discharge space 15. The outer tube 10 and the inner tube 9 also serve as the dielectric of the dielectric barrier discharge. A light extraction window 41 made of a magnesium fluoride disk was provided at one end of the outer tube 10. One end of the inner tube 9 immediately adjacent to the light extraction window 41 was airtightly closed to form a closed portion 16. Reference numerals 11, 12, and 17 denote electrodes, which are made of an aluminum thin film and have a function as a reflecting mirror. Therefore, when turned on by the power source 22, the excimer light emitted from the window 41 becomes a strong beam light. Incidentally, 13 is also a reflection film made of aluminum, and has a role of increasing the intensity of the beam light.

In FIG. 3, 4 krypton are placed in the discharge space 15.
FIG. 6 is an explanatory diagram of data obtained by encapsulating 60 torr and producing a number of lamps with different encapsulation amounts of xenon, and measuring the half-width of the emission spectrum of the lamp. The xenon / krypton atomic ratio widens from 0.01 to 0.5
It becomes the maximum and has the effect of spreading to 0.1. FIG. 2 shows the emission spectrum when the atomic ratio is 0.05.
The spectrum had a center wavelength of 163 nm and a half width of 29 nm, and a half width more than twice that of the single spectrum of xenon and krypton was obtained. When the xenon / krypton atomic ratio was 0.05, the output of the emission spectrum was about 2 W with an electric input of 25 W. Therefore, the wavelength range is wide,
A highly efficient vacuum ultraviolet light source was obtained.

[0008]

As can be understood from the above description, according to the present invention, it is possible to obtain the light source having the radiated light having a wide half width in the vacuum ultraviolet region.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of a dielectric barrier discharge lamp of the present invention.

FIG. 2 is an explanatory diagram of a radiation spectrum.

FIG. 3 is an explanatory diagram of data showing the relationship between the xenon / krypton atomic ratio and the half-value width of the emission spectrum.

[Explanation of Codes] 8 Discharge Vessel 9 Inner Tube 10 Outer Tube 11, 12 Electrode 13 Reflective Film 15 Discharge Space 16 Closed Part 17 Electrode 22 Power Supply 41 Light Extraction Window

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kurosawa 5570-3 Kumano, Miyazaki City, Miyazaki Prefecture (72) Inventor Ryushi Igarashi 1194 Sado, Bessho Town, Himeji City, Hyogo Prefecture Usio Electric Co., Ltd. (72) Inventor Hiromitsu Matsuno 1194 Sado, Bessho Town, Himeji City, Hyogo Prefecture Usio Electric Co., Ltd.

Claims (1)

[Claims] 1. A discharge vessel is filled with a discharge gas that forms excimer molecules by a dielectric barrier discharge, the discharge gas is a mixed gas of xenon and krypton, and the ratio thereof, xenon / krypton is an atomic ratio. A dielectric barrier discharge lamp characterized by being defined in the range of 0.01 to 0.1.