JPH0583380U - Titanium sublimation pump - Google Patents

Abstract

(57) [Abstract] [Purpose] To effectively prevent titanium vapor from entering the vacuum chamber and increase the conductance to increase the exhaust speed. [Structure] Plural stages of orifices 44 and 46 are alternately arranged near the outlet of the titanium sublimation pump 14 so that the vacuum chamber internal space 24 is shaded when viewed from the titanium filament 26. With this, titanium vapor 3
4 is prevented from entering the space 24 inside the vacuum chamber and scattering. Further, since the openings 50, 52, 56 can have a large area for each of the orifices 44, 46, the conductance is increased and the exhaust speed is increased.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a titanium sublimation pump that adsorbs and exhausts gas in a vacuum chamber, and aims to improve the exhaust speed while preventing titanium vapor from entering the vacuum chamber.

[0002]

[Prior Art]

 The titanium sublimation pump vaporizes titanium by energizing the titanium filament, deposits the vapor on the wall surface in the vacuum chamber to form an active titanium film, and the titanium film floats in the vacuum chamber. The inside of the vacuum chamber is brought to an ultrahigh vacuum state by adsorbing and exhausting the existing gas.

A conventional titanium sublimation pump is shown in FIG. A circular opening 12 for mounting a titanium sublimation pump 14 is formed in a vacuum chamber 10 such as a particle accelerator, and a cylindrical container 16 of the titanium sublimation pump 14 has a flange 18 fastened with a bolt 20 to fix outside air to the cylindrical container 16. It is installed in a state where it is shut off.

A space 22 inside the titanium sublimation pump 14 communicates with a space 24 inside the vacuum chamber 10. In the space 22 inside the titanium sublimation pump 14, a titanium filament 26 is disposed with its upper and lower ends supported by electrodes and support rods 28 and 30. The electrode rods 28 and 30 are drawn out to the outside through a current introduction terminal 32.

By energizing the titanium filament 26 from an external power source through the terminals 28a and 30a of the electrode rod, titanium is sublimated, and titanium vapor 34 adheres to the inner wall surface of the container 16 to form an active titanium film 36. The gas molecules formed and floating in the vacuum chamber 10 are adsorbed and exhausted.

A titanium sublimation pump that evacuates a vacuum chamber such as a storage ring of an SOR (synchrotron radiation) device prevents the titanium vapor 34 from entering the vacuum chamber 10 and scattering. An orifice 40 is often provided at the outlet.

[0007]

[Problems to be solved by the device]

 According to the conventional titanium sublimation pump, the gas molecules floating in the vacuum chamber 10 can enter only through the small opening 42 of the orifice 40, so that the conductance (the ease of gas flow) is small and the exhaust gas is exhausted. It had the drawback of being slow.

The present invention solves the above problems in the prior art, and effectively prevents titanium vapor from entering the vacuum chamber while increasing the conductance and increasing the exhaust speed of titanium sublimation. It is intended to provide a pump.

[0009]

[Means for Solving the Problems]

 This invention is directed to a container communicating with a vacuum chamber, a titanium filament contained in the container, a titanium filament current supply path for supplying an electric current to the titanium filament from outside the container, and the titanium filament from the container to In the space leading to the vacuum chamber, the plurality of orifices are arranged alternately in the direction toward the vacuum chamber and form a shade in the vacuum chamber direction with respect to the titanium filament.

[0010]

[Action]

 Since the titanium vapor sublimated from the titanium filament has the property of traveling straight, by arranging multiple stages of orifices in a staggered manner and forming a shadow in the vacuum chamber direction when viewed from the titanium filament, the titanium vapor is introduced into the vacuum chamber. It can be prevented from invading and scattering. Moreover, since the shadows are formed by alternately arranging a plurality of stages of orifices, each orifice can have a large opening area, which increases the conductance and increases the exhaust speed.

[0011]

【Example】

 (Embodiment 1) FIG. 1 shows an embodiment of the present invention. A circular opening 12 for mounting the titanium sublimation pump 14 is formed in the vacuum chamber 10 such as the storage ring of the SOR device, and the cylindrical container 16 of the titanium sublimation pump 14 bolts the flange 18 thereto. It is installed in a state where it is stopped at 20 and the outside air is shut off.

A space 22 inside the titanium sublimation pump 14 communicates with a space 24 inside the vacuum chamber 10. In the space 22 inside the titanium sublimation pump 14, a titanium filament 26 is disposed with its upper and lower ends supported by electrodes and support rods 28 and 30. The electrode rods 28 and 30 are drawn out to the outside through a current introduction terminal 32.

A plurality of stages of orifices 44, 46 are arranged in the space 22 in the container 16 on the way from the titanium filament 26 to the space 24 in the vacuum chamber. The inner orifice 44 is formed in a ring shape having a diameter smaller than that of the outer orifice 46, and is fixed by welding to three rods 48 fixed to the inner peripheral surface of the container 16 by welding. It is held on the central axis. The outer orifice 46 is formed in a large-diameter ring shape and is fixed to the inner peripheral surface of the container 46 by welding.

As a result, the orifices 44 and 46 are alternately arranged in the space 22 that extends from the titanium filament 26 to the vacuum chamber internal space 24, and the vacuum chamber internal space 24 is viewed substantially from the titanium filament 26. It is behind the orifices 44 and 46. The inner peripheral surface of the container 16 and the inner surfaces of the orifices 44 and 46 are smoothly polished by, for example, electrolytic polishing so that titanium vapor is easily attached.

According to the above configuration, titanium is sublimated by energizing the titanium filament 26 from the external power source through the terminals 28a and 30a of the electrode rod, and the titanium vapor 34 becomes the inner wall surface of the container 15 and the orifice 44. , 46 to form an active titanium film 36 on the inner surface thereof, and gas molecules floating in the vacuum chamber 10 are adsorbed and exhausted.

In this case, since the titanium vapor 34 sublimated from the vapor titanium filament 26 goes straight, it is prevented that the titanium vapor 34 is shielded by the orifices 44, 46 and enters the vacuum chamber internal space 24 to be scattered.

Further, the orifice 44 can secure a wide opening area by the opening 50 at the central portion and the opening 52 at the outer periphery (scattering through the opening 50 prevents the support plate at the upper end portion of the titanium filament 26 from being scattered. 54 itself serves as a shield and is prevented.) Since the orifice 46 can form a large opening 56 in the central portion because the orifice 44 is shielded, a wide opening area can be secured. it can. Therefore, the conductance becomes large as compared with the conventional one using the single orifice 40 shown in FIG. 2, and the gas molecules floating in the vacuum chamber 10 easily enter the space 22 in the container 16. , The pumping speed is increased.

Now, the results of simulating the exhaust velocity of the conventional apparatus of FIG. 2 and the apparatus of the present invention of FIG. 1 will be described.

First, in the case of the conventional apparatus of FIG. 2, when the inner diameter B of the opening 42 was 3.6 cm, the exhaust speed was 118 liters / second.

On the other hand, in the device of the present invention shown in FIG. 1, the inner diameter of the container 16 is A, the inner diameter B of the opening 50 is 3.6 cm, the inner diameter of the opening 56 is x, and the outer diameter of the orifice 44 is the opening. Assuming that the inner diameter x of the portion 56 is equal and the distance between the orifices 44 and 46 is sufficiently wide, the pumping speed changes depending on the relationship between A and x. That is, when A = 14.7 cm, x = 10 to 11 cm is preferable, and at this time, an evacuation speed of about 700 liters / second is obtained, and x = 10. A maximum pumping speed of 709 l / sec is obtained at 7 cm. When A = 9.6 cm, x = 6.5 to 8 cm is preferable, and at this time, an evacuation speed of about 330 liters / second is obtained, and when x = 7.2 cm, the maximum evacuation speed is about 334 liters / second. Seconds are obtained.

As described above, according to the device of the present invention shown in FIG. 1, the exhaust speed is significantly improved as compared with the conventional device shown in FIG.

(Second Embodiment) FIG. 3 shows another embodiment of the present invention. This is a three-tiered orientation. The orifices 62, 64, 66 of each stage are formed in a ring shape having a small diameter, a medium diameter and a large diameter, respectively. The orifices 62 and 64 are attached to about three rods 68 and 70, respectively, and are held on the central axis of the container 16. The outer periphery of the orifice 66 is attached to the inner peripheral surface of the container 16 by welding. In this way, the orifices 62, 64, 66 are arranged in a staggered manner to form a shadow in the direction of the vacuum chamber internal space 24 with respect to the titanium filament 26. Therefore, it is possible to prevent titanium vapor from entering the space 24 in the vacuum chamber and scattering. Further, since the orifices 62, 64, 66 can have a large opening area (larger than the two-stage one shown in FIG. 1), the conductance is large and the exhaust speed can be increased.

[0023]

[Example of change]

 In the above-mentioned embodiment, the case where the orifices are arranged in two or three stages has been described, but it is also possible to arrange in multiple stages.

Further, in the above-described embodiment, the orifice is formed in a ring shape, and the inside has a small diameter and the outside has a large diameter. It can be formed in various shapes.

Further, the present invention can be applied to exhaust of various vacuum chambers other than the SOR device.

[0026]

[Effect of the device]

 As described above, according to the present invention, by utilizing the property that the titanium vapor sublimated from the titanium filament travels straight, a plurality of orifices are staggered to form a shadow in the vacuum chamber direction when viewed from the titanium filament. Since the titanium vapor is formed, it is possible to prevent titanium vapor from entering the vacuum chamber and scattering. Moreover, since a plurality of orifices are alternately arranged to form a shadow, each orifice can have a large opening area, which can increase the conductance and increase the exhaust speed.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view and an AA arrow cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional side view showing a conventional device.

FIG. 3 is a sectional side view showing another embodiment of the present invention.

[Explanation of symbols]

10 Vacuum Chamber 14 Titanium Sublimation Pump 16 Container 22 Space 26 Titanium Filament 32 Current Introducing Terminal (Titanium Filament Current Supply Path) 40, 42, 62, 64, 66 Orifice

Claims (1)

[Scope of utility model registration request] 1. A container communicating with a vacuum chamber, a titanium filament contained in the container, a titanium filament current supply path for supplying an electric current to the titanium filament from the outside of the container, and the vacuum from the container. A titanium sublimation pump, comprising: a plurality of orifices arranged alternately in a direction toward the vacuum chamber in a space leading to the chamber and forming a shade in the vacuum chamber direction with respect to the titanium filament.