China's telescope makes breakthrough in measuring solar magnetic field

The world's first solar magnetic-field telescope working in the mid-infrared wavelength has achieved a breakthrough by improving its measurement accuracy, according to Chinese scientists.

The telescope, known as the Accurate Infrared Magnetic Field Measurements of the Sun (AIMS), is a major project supported by the National Natural Science Foundation of China. It is located in the Lenghu township in northwest China's Qinghai Province, at an average altitude of about 4,000 meters.

Scientific data shows that the AIMS telescope has carried out precise measurements of solar vector magnetic fields for the first time with an accuracy exceeding the 10 Gauss level, said Wang Dongguang, chief engineer of Huairou Solar Observing Station of National Astronomical Observatories, under the Chinese Academy of Sciences.

"This means that the telescope has achieved the expected goal of directly measuring the solar magnetic field intensity in the mid-infrared band using a super narrow-band Fourier spectrometer," Wang said.

Wang added that this achievement has broken through the bottleneck problem in the century-long history of solar magnetic field measurements by achieving a leap from indirect to direct measurements.

The AIMS telescope is the world's first device dedicated to observing the mid-infrared solar magnetic field and it aims to reveal the mysteries of the sun in the mid-infrared band.

"Through optical design to eliminate stray light and technologies such as vacuum cooling, we have solved the challenges faced by infrared solar observations in this band, such as high environmental background noise and detector performance degradation," said Feng Zhiwei, a senior engineer at National Astronomical Observatories.

Feng added that the infrared imaging terminal of the telescope consists of three systems, namely, infrared optics, focal plane array detector and vacuum cooling, and all components, including the detector chip, are domestically made.

In addition to its role in the measurement of solar magnetic fields, the AIMS telescope can also explore new scientific avenues in the middle-infrared band, according to Wang.