• Optical frequency comb technology: from ground to space

    分类: 天文学 >> 天文仪器与技术 提交时间: 2024-04-18 合作期刊: 《天文技术与仪器(英文)》

    摘要:Optical frequency combs, as powerful tools for precision spectroscopy and research into optical frequency standards, have driven continuous progress and significant breakthroughs in applications such as time-frequency transfer, measurement of fundamental physical constants, and high-precision ranging, achieving a series of milestone results in ground-based environments. With the continuous maturation and evolution of femtosecond lasers and related technologies, optical frequency combs are moving from ground-based applications to astronomical and space-based applications, playing an increasingly important role in atomic clocks, exoplanet observations, gravitational wave measurements, and other areas. This paper, focusing on astronomical and space-based applications, reviews research progress on astronomical frequency combs, optical clock time-frequency networks, gravitational waves, dark matter measurement, dual-comb large-scale absolute ranging, and high-resolution atmospheric spectroscopy. With enhanced performance and their gradual application in the field of space-based research, optical frequency combs will undoubtedly provide more powerful support for astronomical science and cosmic exploration in the future.

  • Heavy ion energy influence on multiple-cell upsets in small sensitive volumes: From standard to high energies

    分类: 物理学 >> 核物理学 提交时间: 2024-02-29

    摘要: The 28nm process has a high cost-performance ratio and has gradually become the standard for the fieldof radiation-hardened devices. However, owing to the minimum physical gate length of only 35nm, the physicalarea of a standard 6T SRAM unit is approximately 0.16 μm2, resulting in a significant enhancement ofmulti-cell charge-sharing effects. Multiple-cell upsets (MCUs) have become the primary physical mechanismbehind single-event upsets (SEUs) in advanced nanometer node devices. The range of ionization track effectsincreases with higher ion energies, and spacecraft in orbit primarily experience SEUs caused by high-energyions. However, ground accelerator experiments have mainly obtained low-energy ion irradiation data. Therefore,the impact of ion energy on the SEU cross-section, charge collection mechanisms, and MCU patterns andquantities in advanced nanometer devices remains unclear. In this study, based on the experimental platformof the Heavy Ion Research Facility in Lanzhou (HIRFL), low- and high-energy heavy-ion beams were usedto study the SEUs of 28nm SRAM devices. The influence of ion energy on the charge collection processesof small-sensitive-volume devices, MCU patterns, and upset cross-sections was obtained, and the applicablerange of the inverse-cosine law was clarified. The findings of this study are an important guide for the accurateevaluation of SEUs in advanced nanometer devices and for the development of radiation-hardening techniques.