JPS6253076B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention produces hydrogen isotope gas to be used as nuclear fuel in the form of frozen small particles (hereinafter referred to as "ice pellets") in a nuclear fusion device, and The present invention relates to a device for feeding a predetermined position within a device.

Generally, in nuclear fusion devices, hydrogen isotopes (single gas of hydrogen, deuterium, or tritium, or a mixture thereof) are used as fuel to generate high-temperature plasma or maintain the generated high-temperature plasma for a long time. It is necessary to turn the ice pellets into ice pellets and inject and supply them into a vacuum container.

However, hydrogen isotopes, which are gaseous at room temperature and pressure, are produced in the form of small solidified ice pellets.
There are many technical problems in supplying.

The following methods have been proposed to solve this problem.

That is, a gas such as hydrogen is cooled and liquefied to generate droplets from a nozzle, and a charge imparting device is applied to the droplets of hydrogen or the like falling from the droplet generation chamber under pressure conditions that allow the droplets to exist as a liquid. charged using
Furthermore, the charged droplets are floated in a pellet flotation and solidification chamber without contact using a pellet flotation device, and then the pressure in the pellet flotation and solidification chamber is reduced to a pressure condition where the droplets can exist as a solid phase and solidified. It is a means.

Although the equipment used in this method is extremely effective for producing ice pellets,
The problem is that its structure and operating conditions are complex.

In addition, in pellet implosion in an inertial confinement fusion device that uses a high-power laser or charged particle beam (hereinafter referred to as the "beam"), or in high-temperature plasma generation in a magnetic confinement fusion device, a non-contact state occurs in a vacuum space. Since it is necessary to accurately irradiate a certain ice pellet with the beam, it is required to inject the ice pellet at the required frequency and at a desired point within the fusion device with high positional accuracy, but this high positional accuracy is also achieved. This is one of the problems that has not been addressed.

The present invention aims to solve these problems by making it possible to easily generate ice pellets, and to supply the ice pellets to specified positions within a fusion device with desired frequency and high positional accuracy. Production and production of hydrogen isotope ice pellets, which has a simple structure and is easy to operate.
The purpose is to provide a feeding device.

Therefore, the hydrogen isotope ice pellet generation/supply device of the present invention includes: a hydrogen liquefaction device that cools and liquefies a gaseous hydrogen isotope; a storage tank that stores the hydrogen isotope liquefied by the hydrogen liquefaction device;
a dropletization device that converts the hydrogen isotope in the storage tank into droplets and drops them; and a hydrogen isotope droplet that is maintained at a pressure lower than the solidification pressure of the hydrogen isotope droplets and that is output from the dropletization device. an ice pellet generation chamber that receives and solidifies ice pellets to produce small spherical frozen particles, and a differential exhaust chamber installed at the lower end of the ice pellet generation chamber, which collects ice pellets that have passed through the differential exhaust chamber and fallen down. a pellet charging chamber connected to the lower end of the differential evacuation chamber and evacuated to apply a charge; an electron or ion beam generator for charging the pellets installed in the pellet charging chamber; a pellet deceleration device that decelerates the falling pellets by applying an electric field in the opposite direction to the falling direction of the ice pellets; The present invention is characterized in that it is provided with a floating pellet position control device for statically floating and controlling the position, and an ice pellet injection chamber serving as an ice pellet supply connection to which ice pellets are injected from the floating pellet position control device.

Hereinafter, details of the present invention will be explained with reference to the drawings showing one embodiment.

The figure shows a longitudinal section of the hydrogen isotope ice pellet production/supply apparatus of the present invention, which is equipped with a cylindrical vacuum insulated container 1. The vacuum insulated container 1 has a double wall structure, and the space between the double walls is evacuated and maintained in a vacuum state by a vacuum exhaust pipe 2, and an appropriate heat insulating material (not shown) is further inserted. Sometimes I do.

A hydrogen liquefaction device 3 is installed at the upper end of the vacuum insulated container 1.
In the internal space of the vacuum insulated container 1, below the liquefaction device 3, an ice pellet generation chamber 4, a differential evacuation chamber 5, a pellet charging chamber 6, and a pellet injection chamber 7 as a connecting part for supplying ice pellets are located. are connected in sequence, and a pellet deceleration device 8 is provided to decelerate the ice pellets from the pellet charging chamber 6, and a pellet flotation/position control device 9 is configured to decelerate the ice pellets from the pellet charging chamber 6. As will be described later, the ice pellets are made to float and can be controlled in position.

The hydrogen liquefaction device 3 has a cooling cylinder 10.
A cooling pipe 11 is spirally arranged around the cooling cylinder 10, and a liquid hydrogen storage tank 12 is attached to the lower end of the cooling cylinder 10.

The cooling pipe 11 and the storage tank 12 are placed in a heat transfer relationship with the cooling cylinder 10, and the cooling pipe 11 communicates with the storage tank 12 internally. Liquid helium as a refrigerant is supplied to the cooling cylinder 10 from a liquid helium supply pipe 13 to maintain the cooling cylinder 10 at an extremely low temperature. On the other hand, the gaseous hydrogen isotope supplied through the hydrogen isotope gas supply pipe 14 is cooled in the cooling cylinder 10.
It is liquefied and stored in the storage tank 12.

The supply amount of liquid helium and the production amount of liquid hydrogen are determined by the respective supply pipes 13 and 14 and the vaporized helium and vaporized hydrogen isotope exhaust pipes 1, respectively.
This is carried out by controlling conditions such as pressure as shown in Nos. 5 and 16.

The liquid hydrogen stored in the storage tank 12 is subjected to mechanical vibrations by a mechanical vibration element 18 that constitutes a dropletization device provided inside the storage tank 12 or in a nozzle 17 that constitutes a dropletization device for ejecting liquid hydrogen.
Nozzle 17 provided at the lower end of 2 (its inner diameter is determined by the required pellet size, usually 0.05
~1 mm) and fall into the ice pellet generation chamber 4 as droplets.

The ice pellet generation chamber 4 is maintained at a pressure slightly lower than the solidification pressure of hydrogen isotopes (for example, 128 Torr for deuterium), and the liquid hydrogen is kept in the ice pellet generation chamber 4.
As it falls, it evaporates and cools, eventually solidifying into ice pellets. At this time, in order to prevent the liquid hydrogen isotope from solidifying in the nozzle 17, a microheater (not shown) is installed on the outer periphery of the nozzle 17 as necessary.
Overheat 7. Note that the size of the ice pellet mainly depends on the inner diameter of the nozzle 17 and the differential pressure between both ends of the nozzle 17, while the dropping frequency depends on the frequency of the mechanical vibration element 18, and furthermore, the hydrogen droplets solidify. The time required for this (or the falling distance within the ice pellet production chamber) depends on the temperature and pressure of the ice pellet production chamber 4.

The ice pellets generated in the ice pellet generation chamber 4 fall into the differential exhaust chamber 5. The differential pumping chamber 5 pumps ice pellets from the high pressure atmosphere (approximately 100 Torr in the case of deuterium) in the ice pellet generation chamber 4 to a high vacuum atmosphere (10 ^-6 Torr or less) equivalent to the high vacuum atmosphere in the vacuum vessel of a nuclear fusion device. A plurality of orifices 19 for differential pumping.
The differential pumping chambers 5 each include a plurality of differential pumping chambers 5 divided by a respective vacuum pumping pipe 20.
It is exhausted by.

While falling through the differential evacuation chamber 5, the ice pellets are transferred to the high vacuum atmosphere.

In order to easily supply ice pellets to a pellet implosion fusion device using a beam or a magnetic confinement fusion device, a device described below is attached below the differential pumping chamber 5.

That is, below the differential exhaust chamber 5, along the ice pellet falling path, there is a pellet charging chamber 6, a pellet deceleration device 8, and a pellet flotation/position control device 9.
and a pellet fall monitoring device 21 is provided. In the pellet charging chamber 6, the ice pellets that have fallen from the differential exhaust chamber 5 are charged with electrons or ions for charging the pellets.
A beam generator 22 irradiates the device with an electron or ion beam to charge it. At this time, the pellet charging chamber 6 is depressurized by the vacuum exhaust pipe 20 and is in a near-vacuum state, so that a strong electron or ion beam can be injected from the pellet charging electron or ion beam generator 22. Therefore, the ice pellets can be charged efficiently.

The pellet deceleration device 8 is equipped with a plurality of pellet deceleration electrodes 23 that generate an electric field in the opposite direction to the falling direction of the ice pellets, and the charged ice pellets falling at high speed are controlled by passing through the pellet deceleration device 8. The speed is reduced to the maximum possible speed.

The pellet levitation/position control device 9 includes a plurality of electrode groups 24 for controlling the pellet levitation position, and applies a levitation force to prevent the ice pellets from falling and a force to correct the center position of the electrodes to the charged ice pellets by the electric field. The device levitates precisely and stationarily to the center of the electrode without contact. The position of the ice pellet is detected by a plurality of pellet position detectors (e.g. optoelectronic devices) 2.
5 from three axial directions, and by controlling the electric field strength in the position control electrode group 24 based on the detection signal, the position of the stationary floating ice pellet is controlled.

The ice pellet, which is suspended stationary and whose position is controlled, is controlled by the pellet levitation and position control device 9 by cutting off the voltage supplied to the position control electrode group 24.
The pellets are supplied by gravity from within to a desired point within the fusion device (not shown) through the pellet injection chamber 7. This natural fall of the ice pellets is detected by a pellet fall monitoring device 21, and the output signal of this pellet fall monitoring device 21 is used as a communication signal to other element devices in the fusion device system.

Experimental example: Supply hydrogen gas at 1 atm to the hydrogen liquefaction device 3,
When it is cooled to about 15〓 with liquid helium, about 30
After minutes the hydrogen gas begins to liquefy. At this time, when the pressure of the liquid hydrogen was about 200 Torr and the pressure of the ice pellet generation chamber 4 was about 100 Torr, it was observed that hydrogen droplets were generated from the nozzle 17 provided at the lower part of the storage tank 12.

At that time, the diameter of the nozzle was set to about 100 microns,
Uniform hydrogen droplets were generated when vibration was applied. The frequency of generation of hydrogen droplets was approximately 10,000 droplets/second. When this is dropped into the ice pellet generation chamber 4 at approximately 100 Torr, the droplets can be solidified while falling.
Furthermore, by passing through the differential evacuation chamber 5 and pellet injection chamber 7, transfer to a high vacuum atmosphere and position control can be performed.

As described in detail above, according to the hydrogen isotope ice pellet generation/supply device of the present invention, it is possible to easily generate spherical ice pellets of the required dimensions, and to distribute the ice pellets with the required frequency and positional accuracy. As a result, it is possible to obtain a hydrogen isotope ice pellet production/supply device that can be supplied to a designated point within a nuclear fusion device, has a simple structure, and is easy to operate.

In particular, the device of the present invention has the advantage that the ice pellet generation chamber is maintained at a pressure lower than the solidification pressure of the hydrogen isotope droplets, so that the liquid hydrogen that falls into the chamber is cooled while evaporating and becomes ice pellets. There is. Moreover, the above ice pellets are
After passing through a differential pumping chamber, the pellets are efficiently charged by receiving a powerful charging electron or ion beam in a nearly vacuum pellet charging chamber.Thus, the sufficiently charged ice pellets are able to control the floating pellet position. The device accurately controls the position,
This has the effect of ensuring proper supply.

[Brief explanation of the drawing]

The figure is a structural explanatory diagram showing a longitudinal section of a hydrogen isotope ice pellet production/supply apparatus according to an embodiment of the present invention. 1... Vacuum insulation container, 2... Vacuum exhaust pipe, 3...
...Hydrogen liquefaction device, 4...Ice pellet generation chamber,
5... Differential exhaust chamber, 6... Pellet charging chamber, 7...
... Pellet injection chamber, 8 ... Pellet deceleration device, 9
... Pellet flotation and position control device, 10 ... Cooling tube, 11 ... Cooling pipe, 12 ... Storage tank, 13 ... Liquid helium supply pipe, 14 ... Hydrogen isotope gas supply pipe, 15 ... Vaporized helium exhaust Piping, 16...
...Vaporized hydrogen isotope exhaust pipe, 17... Nozzle forming the droplet forming device, 18... Mechanical vibration element forming the droplet forming device, 19... Orifice, 20...
Vacuum exhaust pipe, 21... Pellet fall monitoring device, 2
2... Electron or ion beam generator for charging pellets, 23... Electrode, 24... Electrode group, 25
...Pellet position detector.

Claims (1)

[Scope of Claims] 1. A hydrogen liquefaction device that cools and liquefies a gaseous hydrogen isotope, a storage tank that stores the hydrogen isotope liquefied by the hydrogen liquefaction device, and a hydrogen isotope in the storage tank that liquefies the hydrogen isotope. A droplet forming device that forms droplets and causes them to fall;
an ice pellet generation chamber that is maintained at a pressure lower than the solidification pressure of the hydrogen isotope droplets and receives and solidifies the hydrogen isotope droplets from the dropletization device to produce spherical frozen particles; A differential exhaust chamber installed at the lower end of the generation chamber is connected to the lower end of the differential exhaust chamber and evacuated in order to charge the ice pellets that have passed through the differential exhaust chamber and fallen. a pellet charging chamber; a pellet charging electron or ion beam generator installed in the pellet charging chamber; and a pellet deceleration device that applies an electric field in a direction opposite to the direction in which the ice pellets fall from the pellet charging chamber to decelerate the falling pellets. a floating pellet position control device for controlling the position of ice pellets by floating them statically in a non-contact state, the ice pellets having been charged in the pellet charging chamber and having their falling speed reduced by the pellet deceleration device; and the floating pellet position control device. 1. An apparatus for producing and supplying hydrogen isotope ice pellets, characterized in that an ice pellet injection chamber is provided as an ice pellet supply connection section into which ice pellets are injected. 2. The hydrogen isotope according to claim 1, which is provided with a pellet position detection device that detects the position of the ice pellet in the floating pellet position control device, and a pellet fall monitoring device that detects the falling of the ice pellet. A device for producing and supplying body ice pellets.