锦屏深地核天体物理实验关键反应测量的无窗喷射气体靶的研发

锦屏深地核天体物理实验项目将开展天体物理关键核反应的直接精确测量，为理解恒星演化和元素起源提供关键的实验数据。本项目旨在为锦屏深地核天体物理实验平台研制一个无窗喷射气体靶系统，提供高密度的氦、碳、氮、氧、氖等气体靶，以应用于高流强下对恒星平稳氦燃烧阶段关键的(α,γ)和(α,n)反应、恒星平稳氢燃烧阶段关键的(p,γ)和(p,α)反应的直接测量。该无窗喷射气体靶的有效靶区域可以被限定在约3mm宽；当喷射气压为1500mbar时，靶厚可达到大约1.0E17atoms/cm2。这将是世界上首次把无窗喷射气体靶应用于地下核天体物理实验平台，也是首次在国内把无窗喷射气体靶应用于核天体物理测量，将支撑我国在核天体物理关键反应的实验测量领域处于国际最前沿水平。

The construction of Jinping Underground laboratory for Nuclear Astrophysics (JUNA) aims at precise direct measurements of key reactions in Nuclear Astrophysics, and will provide critical experimental data for better understanding evolution of stars and origin of elements. Present project proposes developing a windowless jet gas target for high density beam in JUNA, to provide high density gas target of helium, carbon, nitrogen, oxygen, neon, etc., for the direct measurements of (α,γ), (α,n) reactions in hydrostatic helium burning and (p, γ), (p, α) reactions in hydrostatic hydrogen burning of stellar evolution. The gas target region could be well confined within about three millimeters. The maximum target thickness of 1.0E17 atoms/cm2 is supposed to be achieved at 1500 mbar of jet inlet pressure. It is the first time in the world that a windowless jet gas target has been applied to Nuclear Astrophysical measurement in a deep underground laboratory, and the first time in China that a windowless jet gas target has been practically used for experiment of Nuclear Astrophysics. JUNA will be at leading level in the world's experimental Nuclear Astrophysics area with installation of this windowless jet gas target.