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JP-2026074769-A - Tilt angle detection mechanism

JP2026074769AJP 2026074769 AJP2026074769 AJP 2026074769AJP-2026074769-A

Abstract

[Problem] To reduce the risk of radiation exposure to workers during maintenance in a steering mirror tilt angle detection mechanism using an optical lever. [Solution] A tilt angle detection mechanism for detecting the tilt angle of a steering mirror that adjusts the direction of travel by reflecting laser light irradiated onto fuel in an arbitrary direction in a laser fusion reactor, comprising: a light emission unit that emits detection light which is low coherence light; an optical fiber that transmits the detection light emitted from the light emission unit and emits it toward a detection surface set on the steering mirror; a light receiving element that receives the detection light reflected from the detection surface and measures its position or intensity; and a tilt angle calculation unit that calculates the tilt angle of the steering mirror or a related value based on the measurement result of the light receiving element. [Selection Diagram] Figure 5

Inventors

  • 我妻 一博

Assignees

  • 株式会社EX-Fusion

Dates

Publication Date
20260507
Application Date
20241021

Claims (9)

  1. This system detects the tilt angle of a steering mirror that adjusts the direction of travel by reflecting the laser beam irradiated onto the fuel in a laser fusion reactor in any direction. A light emission unit that emits detection light, which is low-coherence light, An optical fiber transmits the detection light emitted from the light emission unit and emits it toward the detection surface set on the steering mirror, A light-receiving element that receives the detection light reflected from the surface to be detected and measures its position or intensity, An inclination angle detection mechanism comprising an inclination angle calculation unit that calculates the inclination angle of the steering mirror or a related value based on the measurement result of the light receiving element.
  2. The tilt angle detection mechanism according to claim 1, wherein the light-emitting section comprises an LED or an SLD as a light source.
  3. The tilt angle detection mechanism according to claim 1, wherein a collimator lens is provided between the optical output end face of the optical fiber and the surface to be detected.
  4. The tilt angle detection mechanism according to claim 1, wherein the optical fiber emits detection light from one of the optical emission units toward the detection surfaces of multiple steering mirrors.
  5. The tilt angle detection mechanism according to claim 1, wherein the optical fiber is configured using a polarization-maintaining fiber.
  6. The optical fiber is constructed by connecting multiple optical fiber cables. The adjacent optical fiber cables are connected by ferrules at their respective ends using optical adapters. The tilt angle detection mechanism according to claim 1, wherein the end face of the ferrule is polished into an oblique spherical shape.
  7. The tilt angle detection mechanism according to claim 1, wherein the light emitting unit is installed in a space with a lower radiation dose than the space in which the light receiving element is installed.
  8. The steering mirror and the light-receiving element are installed in a controlled area where the radiation level is above a certain amount. The light emission unit is installed outside the controlled area, The tilt angle detection mechanism according to claim 7, wherein the optical fiber is laid across the inside and outside of the controlled area.
  9. The tilt angle detection mechanism according to claim 1, wherein the steering mirror adjusts its direction of travel by reflecting laser light used to irradiate fuel in a laser fusion reactor.

Description

This invention relates to a tilt angle detection mechanism for detecting the tilt angle of a steering mirror. In recent years, research has been actively conducted toward the practical application of laser fusion reactors, which generate energy by imploding a fuel pellet composed of deuterium and tritium with high-power laser light, thereby inducing a nuclear fusion reaction. One type of laser fusion reactor utilizes a fuel projection mechanism to project fuel pellets at high speed into the reactor body for energy extraction. Simultaneously, high-power pulsed laser light is uniformly irradiated from all directions onto the fuel pellets once they reach a predetermined position within the reactor body (e.g., the center), thereby inducing a fusion reaction. In this type of fuel projection system, energy is continuously generated by repeating the fuel pellet projection and laser irradiation several times per second. It is believed that this energy can be channeled externally to generate millions of kilowatts of electricity. T. Norimatsu et. al. , “Conceptual design and issues of the laser internal fusion test (LIFT) reactor-targets and chamber systems”, Nucl. Fusion, vol. 57 (2017) 116040 A schematic diagram showing a laser fusion reactor according to one embodiment of the present invention.A schematic front side perspective view showing the configuration of the steering mirror in the same embodiment.A schematic rear perspective view showing the configuration of the steering mirror in the same embodiment.This diagram schematically shows the configuration of the steering mirror control mechanism in the same embodiment.This figure schematically shows the configuration of the steering mirror tilt angle detection mechanism of the same embodiment.A schematic diagram showing the configuration of the steering mirror tilt angle detection mechanism in another embodiment. The following describes a steering mirror 100 equipped with a tilt angle detection mechanism 42 according to one embodiment of the present invention, and a laser fusion reactor 200, based on the drawings. The steering mirror 100 of this embodiment is used in a laser fusion reactor 200 that generates energy by imploding fuel pellets P (for example, small spherical fuel composed of deuterium and tritium; however, the constituent elements and shape are not limited thereto) by irradiating them with high-power laser light, thereby causing a nuclear fusion reaction. Specifically, as shown in Figure 1, this laser fusion reactor 200 comprises a reactor body V, a fuel projection mechanism F that projects fuel pellets P into the reactor body V at high speed (for example, about 100 m/s), and a laser irradiation mechanism L that irradiates the fuel with laser light (implosion laser light) in time with the fuel as it reaches a predetermined irradiation position R set within the reactor body V. In this laser fusion reactor 200, fuel pellets P are projected into the reactor body V by the fuel projection mechanism F at a constant period (for example, about 10 Hz), and laser light is sequentially irradiated from the laser irradiation mechanism L to these successively projected fuel pellets P. The laser irradiation mechanism L comprises a laser light source L1 that emits laser light and an optical system L2 that guides the laser light emitted from the laser light source L1 to the fuel pellets P projected into the reactor body V. The laser fusion reactor 200 is equipped with multiple (e.g., 100 or more) laser irradiation mechanisms L, allowing for simultaneous irradiation of the fuel pellets P projected onto the reactor body V with laser light from multiple directions (all around). The laser light source L1 is capable of outputting high-energy pulsed laser light at a high repetition frequency (e.g., approximately 10 Hz) sufficient to implode the fuel pellet P, and is installed outside the reactor body V. The optical system L2 is equipped with multiple mirrors that reflect laser light. This optical system L2 includes a steering mirror 100 (also called a movable mirror) that reflects the laser light in any direction to adjust its direction of travel. The laser irradiation mechanism L drives the steering mirror 100 to adjust the direction of the laser light, thereby irradiating the fuel pellets P, whose passing position is slightly (a few millimeters) off from the center of the irradiation position R each time the laser is projected onto the reactor body V. The following provides a detailed explanation of the steering mirror 100. As shown in Figures 2 and 3, this steering mirror 100 comprises a mirror body 1 that reflects high-energy laser light (implosion laser light), a support portion 2 that supports the mirror body 1, a gimbal mechanism 3 interposed between the mirror body 1 and the support portion 2 to tilt the mirror body 1 at an arbitrary angle relative to the support portion 2, and a control mechanism 4 that drives the gimbal mechanism 3 to control the tilt angle