As a key equipment in controllable nuclear fusion research, the core function of the solar simulator is to reproduce the characteristics of solar radiation and provide a standardized and reproducible light environment for experiments. The technical architecture and performance indicators directly determine the testing accuracy and reliability of nuclear fusion devices.
1、 Core components: Precision collaboration of optical systems
The solar simulator consists of three main modules: light source, focusing system, and homogenization and collimation system. Using xenon lamp as the core light source, its spectral distribution highly overlaps with natural sunlight, covering the visible to near-infrared wavelength range. The spotlight system adopts an ellipsoidal reflector to accurately position the xenon lamp point light source at the first focal point, and through the law of optical reflection, the light energy is directed and converged to the second focal point, achieving efficient collection of light energy. The homogenization system divides the light field through a lens array (compound eye lens), eliminates the central "hot spot" problem, and achieves a spot uniformity of within ± 2%. The collimation system uses a collimating lens to convert divergent light into parallel light, simulating the parallel incidence characteristics of sunlight.
2、 Working principle: Triple breakthrough in light energy manipulation
The principle can be broken down into three steps: "light energy convergence homogenization collimation": the high-intensity light emitted by the xenon lamp is reflected by an ellipsoidal mirror and forms a high irradiance spot at the second focal point; The lens array divides the light spot into hundreds of sub spots and achieves homogenization through superposition effect; The collimating lens further compresses the beam divergence angle, ultimately generating simulated sunlight with high irradiance (up to 1000W/m ²), high uniformity, and high spectral matching on the target test surface.
3、 Collaborative optimization of three performance elements: spectrum, uniformity, and stability
Spectral matching degree: It needs to comply with the IEC60904-9 standard, dividing the 400-1100nm band into six intervals, and controlling the irradiance ratio of each interval within ± 25% of the AM1.5G standard spectrum deviation (standard) to ensure that the experimental data is highly consistent with the real environment.
Spot uniformity: Through the collaborative design of lens array and collimating lens, the difference in irradiance between the center and edge is eliminated, and the uniformity is within ± 2%, meeting the strict requirements for light field consistency in experiments such as photovoltaic modules and material aging.
Long term stability: High stability xenon lamps and dynamic calibration techniques are used to ensure irradiance fluctuations are less than ± 1%/h, reducing experimental errors caused by light source attenuation or environmental interference. For example, a certain model of simulator can still maintain spectral matching and uniformity within ± 2% after continuous operation for 1000 hours.
The solar simulator provides a standardized light environment for controllable nuclear fusion research through the precise coordination of optical systems and the coordinated optimization of performance three elements, becoming a key technical support for promoting the transition of "artificial sun" from experimental devices to commercial power plants.