Vacuum target chamber structure capable of preventing scattered light

Abstract

The utility model discloses a vacuum target chamber structure capable of preventing scattered light, which comprises a vacuum target chamber and an optical fiber head, a target material beam inlet is arranged at the upper end of the vacuum target chamber, and a plurality of windows are arranged on the side wall of the vacuum target chamber. All the windows are positioned on the same horizontal plane, three of the windows are respectively a laser entrance, a laser exit and a detection port, and the laser entrance and the laser exit are arranged oppositely; high lenses are arranged at the laser entrance and the laser exit; the optical fiber head is arranged on the flange plate, the front end of the optical fiber head is located on the inner side of the flange plate, and the rear end of the optical fiber head is located on the outer side of the flange plate. And meanwhile, a concave reflector is arranged on the inner wall of the vacuum target chamber opposite to the detection port, so that LIF spectrums reflected and scattered in the vacuum target chamber can be conveniently focused to the optical fiber head. The device effectively reduces the influence of stray light on a target spectrum, reduces the background noise, improves the signal-to-noise ratio of the spectrum, and improves the measurement precision.

Description

Technical Field

[0001] The utility model belongs to the technical field of detection, relates to a vacuum target chamber, and particularly relates to an ionization structure of a vacuum target chamber for preventing scattered light. Background Art

[0002] Before detecting a target material, a pulsed laser is often used to irradiate a target material particle beam in a vacuum target chamber to extract corresponding LIF spectral information. The vacuum target chamber is vertically arranged, and three windows are provided on the side wall of the vacuum target chamber. High lenses are provided on all three windows. The three windows are located on the same horizontal plane and are respectively a laser inlet, a laser outlet, and a detection port. The laser inlet and the laser outlet are arranged opposite to each other. A vacuum pump is provided at the lower end of the vacuum target chamber to ensure a vacuum environment. The laser generated by a laser generator enters the vacuum target chamber from the laser inlet to ionize the target material and then exits from the laser outlet. At the same time, an optical fiber head is arranged outside the detection port, and the optical fiber head is connected to a spectrometer through an optical fiber. The ions ionized in the vacuum target chamber enter the optical fiber head and then enter the spectrometer for analysis and detection.

[0003] However, in this way, the high lens at the detection port will reflect photons, resulting in spectral attenuation. At the same time, the stray light in the vacuum target chamber will affect the target spectrum, resulting in a large background noise, a low spectral signal-to-noise ratio, and affecting the measurement accuracy. Summary of the Invention

[0004] Aiming at the above deficiencies existing in the prior art, the purpose of the utility model is to provide a vacuum target chamber structure for preventing scattered light. The utility model effectively reduces the influence of stray light on the target spectrum, reduces the background noise, improves the spectral signal-to-noise ratio, and improves the measurement accuracy.

[0005] The technical solution of the utility model is realized as follows:

[0006] A vacuum target chamber structure for preventing scattered light includes a vacuum target chamber and an optical fiber head. A target material beam inlet is provided at the upper end of the vacuum target chamber, a vacuum pump is provided at the lower end of the vacuum target chamber, and a plurality of windows are provided on the side wall of the vacuum target chamber. All the windows are located on the same horizontal plane, and three of the windows are respectively a laser inlet, a laser outlet, and a detection port. The laser inlet and the laser outlet are arranged opposite to each other.

[0007] High lenses are provided at the laser inlet and the laser outlet; a flange is provided at the detection port to seal the detection port. The optical fiber head is arranged on the flange, the front end of the optical fiber head is located inside the flange, and the rear end of the optical fiber head is located outside the flange; at the same time, a concave mirror is provided on the inner wall of the vacuum target chamber opposite to the detection port to facilitate focusing the reflected and scattered LIF spectra in the vacuum target chamber onto the optical fiber head.

[0008] Further, a high reflector is provided between the fiber optic head and the concave mirror. The high reflector is close to the fiber optic head, and a film with the same wavelength as the incident laser is coated on the high reflector for reflecting the incident laser.

[0009] Further, the inner wall of the vacuum target chamber is coated with a reflective material.

[0010] Compared with the prior art, the utility model has the following beneficial effects:

[0011] 1. In the utility model, a concave mirror is arranged on the inner wall of the vacuum target chamber opposite to the detection port. The concave mirror can reflect and focus the scattered LIF spectra in the vacuum target chamber onto the fiber optic head as much as possible, reducing the background noise, improving the spectral signal-to-noise ratio, and enhancing the measurement accuracy. At the same time, the fiber optic head in the utility model is arranged on the flange and located inside the flange. Compared with the prior art that uses a high lens to close the detection port and arranges the fiber optic head outside the high lens of the detection port, it can effectively reduce the reflection of photons by the high lens, reduce the attenuation of photons, further improve the spectral signal-to-noise ratio, and enhance the measurement accuracy.

[0012] 2. In the utility model, a high reflector is arranged between the detection port and the concave mirror. The high reflector can reflect the incident laser, and the characteristic spectral fluorescence can all pass through the high reflector and be collected by the fiber optic head, thereby improving the spectral signal-to-noise ratio and enhancing the measurement accuracy.

[0013] 3. By coating the inner wall of the vacuum target chamber with a reflective material in the utility model, the reflectivity of the laser in the vacuum target chamber can be effectively improved, thereby improving the spectral signal-to-noise ratio and further enhancing the spectral resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 - Structural schematic diagram of the utility model.

[0015] Wherein: 1 - vacuum target chamber; 11 - laser inlet; 12 - laser outlet; 13 - detection port; 2 - fiber optic head; 3 - high reflector; 4 - concave mirror. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The following further describes the utility model in detail with reference to the drawings and specific embodiments.

[0017] Refer to Figure 1 , a vacuum target chamber structure for preventing scattered light, including a vacuum target chamber 1 and a fiber optic head 2. The upper end of the vacuum target chamber 1 is provided with a target beam inlet, the lower end of the vacuum target chamber 1 is provided with a vacuum pump, and the side wall of the vacuum target chamber 1 is provided with a plurality of windows. All the windows are located on the same horizontal plane, and three of the windows are respectively a laser inlet 11, a laser outlet 12, and a detection port 13. The laser inlet 11 and the laser outlet 12 are arranged opposite to each other.

[0018] A high lens is provided at the laser entrance 11 and the laser exit 12 to seal the laser entrance and the laser exit; a flange is provided at the detection port 13 to seal the detection port 13. The optical fiber head 2 is disposed on the flange, with the front end of the optical fiber head located inside the flange and the rear end of the optical fiber head located outside the flange. At the same time, a large-diameter concave mirror 4 is provided on the inner wall of the vacuum target chamber opposite to the detection port, facilitating focusing the LIF spectra reflected and scattered in the vacuum target chamber 1 onto the optical fiber head 2.

[0019] In this way, the concave mirror can reflect and focus the LIF spectra reflected and scattered in the vacuum target chamber onto the optical fiber head as much as possible, reducing the background noise, improving the spectral signal-to-noise ratio, and improving the measurement accuracy. At the same time, the detection port here is sealed with a flange made of stainless steel. The optical fiber head is disposed on the flange and located inside the flange. Compared with the prior art where a high lens is used to seal the detection port and the optical fiber head is disposed outside the high lens of the detection port, it can effectively reduce the reflection of photons by the high lens, reduce the attenuation of photons, and further improve the spectral signal-to-noise ratio and the measurement accuracy.

[0020] In this embodiment, the detection port is orthogonal to the straight line where the laser entrance and the laser exit are located. In practical applications, there can be multiple groups of laser entrances and laser exits, but the laser entrances and the laser exits are arranged in a one-to-one facing manner. At the same time, the detection port is not necessarily orthogonal to the straight line where the laser entrances and the laser exits are located.

[0021] During specific implementation, a high-reflection mirror 3 is provided between the optical fiber head 2 and the concave mirror 4. The high-reflection mirror 3 is close to the optical fiber head 2, and a film with the same wavelength as the incident laser is coated on the high-reflection mirror 3 for reflecting the incident laser.

[0022] The wavelength of the film coated on the high-reflection mirror here is the same as the wavelength of the incident laser, so that the incident laser can be reflected, and the characteristic spectral fluorescence can all pass through the high-reflection mirror and be collected by the optical fiber head, thereby improving the spectral signal-to-noise ratio and the measurement accuracy.

[0023] During specific implementation, the inner wall of the vacuum target chamber 1 is coated with a reflective material (not shown in the figure). In this way, the reflectivity of the laser in the vacuum target chamber can be improved, enabling the characteristic spectral fluorescence to be reflected to the detection port, thereby improving the spectral signal-to-noise ratio, the spectral resolution, and the measurement accuracy.

[0024] Finally, it should be noted that the above embodiments of the present invention are merely examples for explaining the present invention and are not limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes and modifications can be made based on the above description. It is impossible to list all the implementation manners here. Any obvious changes or modifications derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. A vacuum chamber structure for preventing scattered light, comprising a vacuum chamber and an optical fiber head. The upper end of the vacuum chamber is provided with a target material beam inlet, the lower end of the vacuum chamber is provided with a vacuum pump, and several windows are provided on the side wall of the vacuum chamber. All the windows are located on the same horizontal plane, and three of the windows are respectively a laser inlet, a laser outlet and a detection port. The laser inlet and the laser outlet are arranged opposite to each other; It is characterized in that: High lenses are provided at the laser inlet and the laser outlet; A flange is provided at the detection port to seal the detection port. The optical fiber head is arranged on the flange, the front end of the optical fiber head is located inside the flange, and the rear end of the optical fiber head is located outside the flange; At the same time, a concave mirror is provided on the inner wall of the vacuum chamber opposite to the detection port, which is convenient for focusing the LIF spectra reflected and scattered in the vacuum chamber onto the optical fiber head.

2. The vacuum target chamber structure for preventing scattered light according to claim 1, characterized in that, A high reflector is provided between the optical fiber head and the concave mirror. The high reflector is close to the optical fiber head, and a film with the same wavelength as the incident laser is coated on the high reflector for reflecting the incident laser.

3. The vacuum target chamber structure for preventing scattered light according to claim 1 or 2, characterized in that The inner wall of the vacuum chamber is coated with a reflective material.

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