JP6143149B2 - Liquid metal target forming apparatus and neutron generator - Google Patents

Description

  The present invention relates to a liquid metal target forming apparatus and a neutron generating apparatus that form a target that irradiates a proton beam by ejecting a liquid metal.

  FIG. 8 is a block diagram showing a conventional liquid metal loop. The liquid metal loop 900 includes a target forming unit 901 for irradiating a proton beam to obtain neutrons, a quench tank 902 disposed downstream of the target forming unit 901, and a circulation pump 903 connected to the quench tank 902. And a heat exchanger 904 disposed downstream of the circulation pump 903. These are connected by a pipe 906 to form a loop as a whole. The target 901 is of a type in which liquid lithium is pressed against the curved back plate 905 by centrifugal force to form a liquid lithium film flow on the back plate 905. As a conventional liquid metal loop 900, the one described in Patent Document 1 is known.

JP 2001-33600 A

  When the operation of the liquid metal loop 900 is started, liquid lithium flows on the back plate 905, and a liquid lithium film flow is formed. The liquid lithium has a problem that it spills or scatters around the target forming portion 901 because centrifugal force does not work when it is jetted. The present invention has been made to solve such problems.

  A liquid metal target forming apparatus according to a first aspect of the present invention includes a nozzle that ejects liquid metal and a receiving portion that receives the liquid metal ejected from the nozzle, and a proton beam irradiation space between the nozzle and the receiving portion. A target forming portion for forming a liquid metal target, and the nozzle and the receiving portion so that the nozzle and the receiving portion are moved relative to each other in a liquid metal ejection direction from the target forming position to the receiving portion. The first movement support means for supporting one or both of the above and the expansion / contraction cylinder body provided on the nozzle side or the receiving portion side and capable of expanding and contracting in the liquid metal ejection direction.

  In the present invention, when the target forming apparatus is started or stopped, the nozzle and the receiving part are relatively moved by the first moving support means so that the nozzle tip reaches the receiving part. The relative movement between the nozzle and the receiving part is absorbed by the telescopic cylinder. Thereby, the liquid metal ejected from the nozzle is directly ejected to the receiving part. At the time of activation, the nozzle tip is kept close to the receiving part, and when the liquid metal ejection moment is stabilized, the nozzle is moved from the receiving part to the target forming position by the first movement support means. When stopping, the nozzle is moved close to the receiving portion by the moving support means and then stopped. In this way, the liquid metal does not spill or scatter.

  A liquid metal target forming apparatus according to a second invention includes a nozzle for ejecting liquid metal and a receiving portion for receiving the liquid metal ejected from the nozzle, and a proton beam irradiation space between the nozzle and the receiving portion. A target forming portion for forming a liquid metal target, and a tray disposed below the nozzle and the receiving portion, and having a width longer than the interval between the nozzle and the receiving portion and wider than the width of the target, Retracting means for retracting the tray from below between the nozzle and the receiving portion is provided.

  In the present invention, when the target forming apparatus is activated or stopped, the liquid metal ejected from the nozzle is received by the tray even if it spills between the nozzle and the receiving portion. When the proton beam is irradiated, the tray is retracted from below between the nozzle and the receiving portion by the retracting means. In this way, the liquid metal does not spill or scatter.

  A liquid metal target forming apparatus according to a third aspect of the present invention includes a nozzle that ejects liquid metal and a receiving portion that receives the liquid metal ejected from the nozzle, and a proton beam irradiation space between the nozzle and the receiving portion. A target forming part for forming a liquid metal target, a telescopic cylinder provided on the receiving part side and capable of expanding and contracting in the liquid metal ejection direction, and extending the tip of the telescopic cylinder from the target forming position to the nozzle tip And a second movement support means for movably supporting.

  In the present invention, when the target forming apparatus is activated or stopped, the tip of the telescopic cylinder is moved to the tip of the nozzle by the second movement support means. The telescopic cylinder is extended by the movement of the tip, and the receiving portion and the nozzle tip are connected by the telescopic cylinder. For this reason, even if the liquid metal ejected from the nozzle spills between the nozzle and the receiving portion, it is received by the telescopic cylinder. When the momentum of liquid metal injection is stabilized, the tip of the telescopic cylinder is moved away from the nozzle to the target formation position by the second movement support means. At the time of stopping, the moving support means brings the tip of the telescopic cylinder close to the tip of the nozzle and then stops. In this way, the liquid metal does not spill or scatter. The telescopic cylinder is, for example, a bellows or a telescopic cylinder.

  A liquid metal target forming apparatus according to a fourth aspect of the present invention includes a nozzle for ejecting liquid metal and a receiving portion for receiving the liquid metal ejected from the nozzle, and a proton beam irradiation space between the nozzle and the receiving portion. And a third moving support means for moving the nozzle and the receiving portion to a posture in which the jet direction of the liquid metal is a vertical direction.

  In the present invention, when the apparatus for forming a target is started or stopped, the third moving support means moves the nozzle and the receiving portion to a posture in which the liquid metal ejection direction is a vertical direction. By ejecting the liquid metal in this state, the liquid metal falls vertically to the receiving portion, so that the liquid metal does not spill. When the liquid metal injection momentum is stabilized, the third moving support means moves the nozzle and the receiving portion to a predetermined position (horizontal direction or the like). At the time of stop, the third movement support means moves the liquid metal to the above-mentioned posture while ejecting the liquid metal so that the liquid metal falls vertically to the receiving portion. Even if the ejection of the liquid metal is stopped in this state, the liquid metal spilling from the nozzle tip falls to the receiving portion. According to such a configuration, the liquid metal is not spilled or scattered.

  A neutron generator according to a fifth aspect of the present invention includes the liquid metal target forming apparatus according to any one of the above.

It is a block diagram which shows the liquid metal loop concerning Embodiment 1 of this invention. It is a block diagram which shows another example of the liquid metal loop shown in FIG. It is a block diagram which shows the liquid metal loop which concerns on Embodiment 2 of this invention. It is a top view which shows the target formation part vicinity of the liquid metal loop shown in FIG. It is a block diagram which shows the liquid metal loop which concerns on Embodiment 3 of this invention. It is a block diagram which shows another example of the liquid metal loop shown in FIG. It is a block diagram which shows the liquid metal loop which concerns on Embodiment 4 of this invention. It is a block diagram which shows the conventional liquid metal loop.

(Embodiment 1)
1A and 1B are configuration diagrams showing a liquid metal loop according to a first embodiment of the present invention, where FIG. 1A shows a state during startup and stop, and FIG. 1B shows a state during operation. The liquid metal loop 100 includes a target forming unit 1 that forms a liquid lithium target T, a quench tank 2 connected to the target forming unit 1, and a circulation pump 3 connected to a pipe 4 extending from the quench tank 2. The piping 4 extending from the circulation pump 3 is connected to the target forming unit 1 again.

  The target forming unit 1 includes a nozzle 11 that ejects liquid lithium in a plane so as to cross the irradiation region of the proton beam B, and a receiving unit 12 that receives the ejected liquid lithium. The nozzle 11 has, for example, a strip-shaped or rectangular discharge port with straight or smooth sides (not shown) at the tip. The liquid lithium ejected from the discharge port at a high pressure becomes a film-like jet and is received while being buffered by the receiving portion 12.

  The receiving part 12 is connected to the upper side surface of the quench tank 2 in a substantially horizontal direction. In addition, the receiving part 12 may be connected to the quench tank 2 via piping. In addition, the opening of the receiving portion 12 has a shape and size that allows the tip of the nozzle 11 to be inserted. The nozzle 11 is supported by a moving support portion 13 that moves in the liquid lithium ejection direction. This movement support part 13 is the structure which supports the said nozzle 11 with the block 15 of the linear guide 14 by which the rail is arrange | positioned in the ejection direction of liquid lithium. In addition, a slide type linear motion guide may be adopted. The movement of the nozzle 11 is performed by a linear motion actuator comprising a combination of a hydraulic cylinder or a ball screw and a servo motor (not shown). The linear actuator is controlled by the controller 16.

  The nozzle 11 is provided with an expandable / contractible bellows 17 in the liquid lithium ejection direction. The expandable span of the bellows 17 is substantially equal to the target length when the target is formed with liquid lithium. The bellows 17 is composed of a plurality of ring-shaped members, and has a structure capable of expanding and contracting by welding the outer peripheries or the inner peripheries of adjacent ring-shaped members.

  Next, the operation of the liquid metal loop 100 will be described. Before starting or not during operation, the bellows 17 is extended and the tip of the nozzle 11 is inserted into the receiving portion 12 as shown in FIG. By operating the circulating pump 3 in this state and supplying liquid lithium to the nozzle 11 of the target forming unit 1, liquid lithium is ejected from the nozzle 11. At the time of start-up, the liquid lithium is directly jetted from the discharge port of the nozzle 11 to the receiving part 12. Then, after the start of injection, the controller 16 moves the linear actuator to contract the bellows 17 and gradually separate the nozzle 11 from the receiving portion 12. Since liquid lithium is ejected from the discharge port of the nozzle 11 at a predetermined flow rate, liquid lithium does not spill between the nozzle 11 and the receiving portion 12 even if the nozzle 11 is separated from the receiving portion 12.

  The nozzle 11 moves to a predetermined position (target formation position) for forming the target T and stops. In this state, a target T having a predetermined length is formed between the nozzle 11 and the receiving portion 12 using film-like liquid lithium. When this film-like liquid lithium target T is irradiated with a proton beam B, neutrons N are generated behind it. Liquid lithium heated by irradiation with the proton beam B enters from the receiving portion 12 and is introduced into the quench tank 2.

  On the other hand, when stopping the operation, the controller 16 drives the linear motion actuator to extend the bellows 17 and move the nozzle 11 toward the receiving portion 12. After the tip of the nozzle 11 is inserted into the receiving portion 12, the controller 16 stops the operation of the circulation pump 3 and stops the supply of liquid lithium to the nozzle 11. Liquid lithium that spills when discharge is stopped from the discharge port of the nozzle 11 is received by the receiving portion 12, so that liquid lithium does not spill between the nozzle 11 and the receiving portion 12.

  As described above, the target forming unit 1 forms the target T by blowing a jet of liquid lithium between the nozzle 11 and the receiving unit 12, and forms a liquid film on the curved back wall as in the conventional case. Therefore, there is no structure between the nozzle 11 and the receiving portion 12. For this reason, liquid lithium spills between the nozzle 11 and the receiving portion 12 at the time of starting and stopping, and the tip of the nozzle 11 is inserted into the receiving portion 12 at the time of starting and stopping as described above. This can be prevented.

  Further, the target forming unit 20 may be configured such that the receiving unit 12 moves as shown in FIG. In the liquid metal loop 150, as shown in FIG. 2, an expandable bellows 17 similar to the above is disposed between the receiving portion 12 and the quench tank 2. The expandable span of the bellows 17 is substantially equal to the target length when forming the target with liquid lithium. The receiving part 12 is supported by the same movement support part 13 as described above.

  In the liquid metal loop 150, the bellows 17 is extended and the receiving portion 12 is inserted at the tip of the nozzle 11 before starting and when not in operation. At startup, the circulating pump 3 is operated to supply liquid lithium to the nozzle 11 of the target forming unit 20, so that liquid lithium is directly injected from the discharge port of the nozzle 11 to the receiving unit 12. Then, after the injection is started, the linear actuator is moved by the controller 16 to contract the bellows 17, and the receiving portion 12 is gradually separated from the nozzle 11. Since the liquid lithium is ejected from the discharge port of the nozzle 11 at a predetermined flow rate, the liquid lithium does not spill between the nozzle 11 and the receiving part 12 even if the receiving part 12 is separated from the nozzle 11.

  The receiving part 12 moves to a predetermined position (target formation position) for forming the target T and stops. In this state, a target T having a predetermined length is formed between the nozzle 11 and the receiving portion 12 using film-like liquid lithium. When this film-like liquid lithium target T is irradiated with a proton beam B, neutrons N are generated behind it. Liquid lithium heated by irradiation with the proton beam B enters from the receiving portion 12, passes through the bellows 17, and is introduced into the quench tank 2.

  On the other hand, when stopping the operation, the controller 16 drives the linear actuator to extend the bellows 17 and move the receiving portion 12 in the direction of the nozzle 11. After the receiving part 12 is inserted into the tip of the nozzle 11, the controller 16 stops the operation of the circulation pump 3 and stops the supply of liquid lithium to the nozzle 11. Since the liquid lithium spilled when the discharge is stopped from the discharge port of the nozzle 11 is received by the receiving portion 12, the liquid lithium is not spilled between the nozzle 11 and the receiving portion 12.

(Embodiment 2)
3A and 3B are configuration diagrams showing a liquid metal loop according to Embodiment 2 of the present invention, where FIG. 3A shows a state during start and stop, and FIG. 3B shows a state during operation. FIG. 4 is a plan view showing the vicinity of the target forming portion of the liquid metal loop. The liquid metal loop 200 includes a target forming unit 21 that forms a liquid lithium target T, a quench tank 2 connected to the target forming unit 21, and a circulation pump 3 connected to a pipe 4 extending from the quench tank 2. The pipe 4 extending from the circulation pump 3 is connected to the target forming unit 21 again.

  The target forming unit 21 includes a nozzle 11 that ejects liquid lithium in a plane so as to cross the irradiation region of the proton beam B, and a receiving unit 12 that receives the ejected liquid lithium. The nozzle 11 has, for example, a strip-shaped or rectangular discharge port with straight or smooth sides on the tip. The liquid lithium ejected from the discharge port at a high pressure becomes a film-like jet. The liquid lithium that has become a jet is buffered by the receiving portion 12. The receiving portion 12 is connected to the upper side surface of the quench tank 2 in a horizontal direction. Note that the receiving portion 12 may be connected to the quench tank 2 via the pipe 4.

  Since the target forming unit 21 forms the target T by blowing a jet of liquid lithium between the nozzle 11 and the receiving unit 12, there is no structure between the nozzle 11 and the receiving unit 12. For this reason, liquid lithium is spilled between the nozzle 11 and the receiving part 12 at the time of starting and stopping, so the spill prevention structure 22 is provided below the nozzle 11 and the receiving part 12.

  The spill prevention structure 22 includes a bowl-shaped tray 23 having a concave cross section in the short side direction, a rotating device 24 that rotates the tray 23, and a drain pipe 25 that puts liquid lithium received in the tray 23 into the quench tank 2. Composed. The length of the tray 23 is larger than the distance between the nozzle 11 and the receiving portion 12 when the target T is formed. The width of the tray 23 is set to be larger than the width of the target T (discharge port of the nozzle 11) to be formed. A discharge pipe 26 is provided at the end of the tray 23.

  The rotating device 24 is preferably a hydraulic rotary actuator that is not affected by the magnetic force on the liquid lithium. The rotating shaft is provided on the nozzle 11 side of the tray 23. The hydraulic pressure supply to the rotation device 24 is controlled by the controller 16. The front end of the drain pipe 25 connected to the quench tank 2 is bent upward, and a tray 27 is provided at the end thereof.

  Next, the operation of the liquid metal loop 200 will be described. Before starting or stopping when not in operation, the tray 23 is positioned below the space between the nozzle 11 and the receiving portion 12 along the liquid lithium ejection direction, as shown in FIG. When the circulating pump 3 is operated at the time of startup and liquid lithium is supplied to the nozzle 11 of the target forming unit 21, liquid lithium spilled downward from the nozzle 11 falls onto the tray 23. The liquid lithium on the tray 23 is discharged from the discharge pipe 26, collected by the receiving tray 27, and introduced into the quench tank 2 through the drain pipe 25.

  After a certain period of time has elapsed since startup, the liquid lithium jet becomes a film and enters the receiving part 12 directly. After the target T is formed by the liquid lithium jet, since the liquid lithium does not spill downward, as shown in FIG. 3B, the controller 16 drives the rotating device 24 to move the tray 23 to 90 degrees. Rotate. Thereby, the tray 23 is retracted from below the target T. When this target T is irradiated with a proton beam B, neutrons N are generated behind it. Liquid lithium heated by irradiation with the proton beam B enters from the receiving portion 12 and is introduced into the quench tank 2. The proton beam B can be irradiated from any direction above and below the target T.

  On the other hand, when the operation is stopped, the controller 16 drives the rotation device 24 to rotate the tray 23 by 90 degrees and position it again below the target T as shown in FIG. In this state, the controller 16 stops the operation of the circulation pump 3 and stops the supply of liquid lithium to the nozzle 11. Liquid lithium that spills when discharge is stopped from the discharge port of the nozzle 11 is received by the tray 23 and introduced into the quench tank 2, so that liquid lithium does not spill between the nozzle 1 and the receiving portion 12.

(Embodiment 3)
5A and 5B are configuration diagrams showing a liquid metal loop according to Embodiment 3 of the present invention, where FIG. 5A shows a state during startup and stop, and FIG. 5B shows a state during operation. This liquid metal loop 300 is characterized in that the spill prevention structure 22 of the liquid metal loop 200 of the second embodiment is configured by the bellows 31. The spillage prevention structure 32 of the liquid metal loop 300 is constituted by an expandable / contractible bellows 31, one end of the bellows 31 is connected to the receiving portion 12, and the other end 31a is movable. The other end 31a is supported by moving means 33 that moves in the liquid lithium ejection direction. The moving means 33 is configured to support the other end of the nozzle 11 by a block 35 of a linear guide 34 in which rails are arranged in the liquid lithium ejection direction. In addition, a slide type linear motion guide may be adopted. The movement of the nozzle 11 is performed by a linear motion actuator comprising a combination of a hydraulic cylinder or a ball screw and a servo motor. The linear actuator is controlled by the controller 16.

  The expandable span of the bellows 31 is substantially equal to the target length when the target is formed with liquid lithium. The bellows 31 is composed of a plurality of ring-shaped members surrounding the target T, and has a general structure in which the outer peripheries or inner peripheries of adjacent ring-shaped members are welded to expand and contract.

  Next, the operation of the liquid metal loop 300 will be described. Before starting or stopping when not in operation, the bellows 31 is extended and the other end 31 a is inserted into the tip of the nozzle 11 as shown in FIG. When the circulation pump 3 is operated to supply liquid lithium to the nozzle 11 of the target forming unit 30, liquid lithium is ejected from the nozzle 11. At the time of ejection, liquid lithium does not reach the receiving portion 12 and is received by the bellows 31. For this reason, liquid lithium does not spill between the nozzle 11 and the receiving portion 12.

  After elapse of a predetermined time from the ejection, a target T having a predetermined length made of film-like liquid lithium is formed in the bellows 31 between the nozzle 11 and the receiving portion 12. The controller 16 moves the other end 31a of the bellows 31 by a linear actuator to move the other end 31a away from the nozzle 11 and retract it to a predetermined position. Thereby, the target T appears by the retraction of the bellows 31. When this film-like liquid lithium target T is irradiated with a proton beam B, neutrons N are generated behind it. Liquid lithium heated by irradiation with the proton beam B enters from the receiving portion 12 and is introduced into the quench tank 2.

  On the other hand, when stopping the operation, the controller 16 drives the linear actuator to move the other end 31a of the bellows 31 so as to cover the target T. After putting the other end 31 a of the bellows 31 on the tip of the nozzle 11, the controller 16 stops the operation of the circulation pump 3 and stops the supply of liquid lithium to the nozzle 11. Since the liquid lithium spilled when the discharge is stopped from the discharge port of the nozzle 11 is received by the bellows 31, the liquid lithium is not spilled between the nozzle 11 and the receiving portion 12.

  In place of the bellows 31, a telescopic cylindrical body 36 as shown in FIG. 6 may be used. In the case of this liquid metal loop 350, one end of the cylindrical body 36 is connected to the receiving portion 12, and the other end 36 a is supported by the moving means 33. Even when the spill prevention structure 32 is configured by the telescopic cylinder 36, the liquid lithium can be prevented from spilling by extending the cylinder to the nozzle 11 and covering it at the start or stop as shown in FIG. 6A. . During operation (at the time of beam irradiation), as shown in FIG. 6B, the cylindrical body 36 is contracted to expose the target T, and the proton beam B is irradiated. Even in such a configuration, the same effect as described above can be obtained.

(Embodiment 4)
7A and 7B are configuration diagrams showing a liquid metal loop according to Embodiment 4 of the present invention, where FIG. 7A shows a state during startup and stop, and FIG. 7B shows a state during operation. The liquid metal loop 400 includes a target forming unit 40 that forms a liquid lithium target, a quench tank 2 that is connected from the target forming unit 40 through a pipe 4, and a circulation pump that is connected to the pipe 4 that extends from the quench tank 2. 3 and the pipe 4 extending from the circulation pump 3 is connected to the target forming unit 40 again.

  The target forming unit 40 includes a nozzle 11 that ejects liquid lithium in a plane so as to cross the irradiation region of the proton beam B, and a receiving unit 12 that receives the ejected liquid lithium. The nozzle 11 has, for example, a strip-shaped or rectangular discharge port with straight or smooth sides on the tip. The liquid lithium ejected from the discharge port at a high pressure becomes a film-like jet. The liquid lithium that has become a jet is buffered by the receiving portion 12.

  Moreover, the target formation part 40 is a structure which can switch the jet direction of liquid lithium to a horizontal direction and a vertical direction. Specifically, the nozzle 11 and the receiving portion 12 are pivotally supported via a pipe 4 on a rotating shaft 41 having an angle of 45 degrees with respect to the horizontal direction. A rotary joint 42 is provided on the pipe 4 connected to the nozzle 11 and the receiving portion 12. The rotary joint 42 is provided on the pipe 4 at a position that can rotate around the rotary shaft 41. The target forming unit 40 is rotated by an actuator (not shown).

  Next, the operation of the liquid metal loop 400 will be described. Before starting or stopping when not in operation, as shown in FIG. 7A, the nozzle 11 and the receiving portion 12 are in the vertical direction so that the liquid metal ejection direction of the target forming portion 40 is in the vertical direction. To position. By operating the circulation pump 3 and supplying liquid lithium to the nozzle 11 of the target forming unit 40, liquid lithium is ejected downward from the nozzle 11. Since the receiving part 12 is located below, liquid lithium falls directly on the receiving part 12 at the time of ejection. For this reason, liquid lithium does not spill.

  After a lapse of a predetermined time from the ejection, a target T made of film-like liquid lithium is formed between the nozzle 11 and the receiving portion 12. As shown in FIG. 7B, the controller 16 drives the actuator so that the nozzle 11 and the receiving part 12 are centered on the rotating shaft 41 until the liquid lithium ejection direction of the target forming part 40 becomes horizontal. Rotate as Since liquid lithium is ejected at high speed, the ejected state can be maintained even if it is rotated. When the target T in the horizontal direction is irradiated with the proton beam B, neutrons N are generated behind it. Liquid lithium heated by irradiation with the proton beam B enters from the receiving portion 12 and is introduced into the quench tank 2.

  On the other hand, when stopping the operation, the controller 16 drives the actuator to rotate the target forming unit 40 around the rotating shaft 41 so that the liquid lithium is ejected in the vertical direction. In this state, the controller 16 stops the operation of the circulation pump 3 and stops the supply of liquid lithium to the nozzle 11. Liquid lithium that spills when discharge is stopped from the discharge port of the nozzle 11 falls and is received by the receiving portion 12 as it is, so that liquid lithium does not spill.

  Further, in the state shown in FIG. 7A, the neutron N may be generated by irradiating the proton beam B from the horizontal direction. In this case, the patient will be treated while sitting or standing. For example, it is useful when treating the face or the side of the body.

  In addition, the target formation part of the said Embodiment 1-4 can be thought of as the neutron generator which generates the neutron N by irradiating the proton beam B. Further, the liquid metal is not limited to the liquid lithium disclosed in the above embodiment.

DESCRIPTION OF SYMBOLS 100 Liquid metal loop 1 Target formation part 2 Quench tank 3 Circulation pump 4 Piping 11 Nozzle 12 Receiving part 13 Movement support part 16 Controller 17 Bellows

Claims (5)

A target forming unit for forming a liquid metal target in a proton beam irradiation space between the nozzle and the receiving unit, and having a receiving unit for receiving the liquid metal ejected from the nozzle, and a receiving unit for receiving the liquid metal ejected from the nozzle;
One or both of the nozzle and the receiving part are supported so that the nozzle and the receiving part are relatively moved from the target formation position to the receiving part in the liquid metal ejection direction at the time of starting or stopping. First moving support means;
A telescopic cylinder provided on the nozzle side or the receiving portion side and capable of expanding and contracting in the liquid metal ejection direction;
An apparatus for forming a liquid metal target, comprising: A target forming unit for forming a liquid metal target in a proton beam irradiation space between the nozzle and the receiving unit, and having a receiving unit for receiving the liquid metal ejected from the nozzle, and a receiving unit for receiving the liquid metal ejected from the nozzle;
A tray disposed below the nozzle and the receiving portion, and having a width longer than the interval between the nozzle and the receiving portion and wider than the width of the target;
Retreating means for retreating the tray from below between the nozzle and the receiving portion during irradiation of the proton beam;
With
The nozzle, the liquid metal target forming apparatus comprising a horizontal positioning of Reruko the receiving unit. A target forming unit for forming a liquid metal target in a proton beam irradiation space between the nozzle and the receiving unit, and having a receiving unit for receiving the liquid metal ejected from the nozzle, and a receiving unit for receiving the liquid metal ejected from the nozzle;
An extendable cylindrical body provided on the receiving portion side and capable of expanding and contracting in the liquid metal ejection direction;
A second moving support means for supporting the tip of the telescopic cylinder so as to be movable from the target formation position to the tip of the nozzle when starting or stopping;
An apparatus for forming a liquid metal target, comprising: A target forming unit for forming a liquid metal target in a proton beam irradiation space between the nozzle and the receiving unit, and having a receiving unit for receiving the liquid metal ejected from the nozzle, and a receiving unit for receiving the liquid metal ejected from the nozzle;
Third moving support means for moving the nozzle and the receiving portion to a posture in which the ejection direction of the liquid metal is vertical when starting or stopping;
An apparatus for forming a liquid metal target, comprising: A neutron generator comprising the liquid metal target forming apparatus according to any one of claims 1 to 4.

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