锦屏深地核天体物理实验(JUNA)进展

Progress of Jinping Underground Nuclear Astrophysics Experiment (JUNA)

锦屏深地核天体物理实验(JUNA)项目将利用中国锦屏深地实验室(CJPL)的良好条件,在天体物理伽莫夫能量窗口开展核天体关键反应25Mg(p,γ)26Al、19F(p,α)16O、13C(α,n)16O和12C(α,γ)16O的直接测量。目前已成功完成400kV强流加速器和ECR离子源的研发,获得了400keV、10mA的质子束流和一价氦离子束流及800keV、2mA二价氦离子束流。大功率固体靶的研制及实验数据获取系统的建立也已成功完成。超低本底快中子探测器、4πBGO探测器阵列以及大立体角带电粒子探测器阵列已研制组装完成,并测量了地面和锦屏地下实验室的本底水平。总体来说,JUNA项目整体进展顺利,完成了中期设立的目标并通过了基金委评估(A级)和国际评估。

Jinping Underground Nuclear Astrophysics Experiment (JUNA) will take the advantage of the ultra-low background in China Jinping Underground Laboratory ( CJPL ).A number of nuclear reactions important to hydrostatic stellar evolution near their Gamow window energy such as 25Mg(p,γ) 26Al,19F(p,α) 16O,13C(α,n) 16O and 12C(α,γ) 16O will be directly measured.At present,400 kV high current accelerator and ECR ion source were successfully developed,and the proton and He^+(400 keV,10 mA) and He^2+ beam (800 keV,2 mA) were successfully obtained.The development of high-power solid targets and the establishment of experimental data acquisition systems were successfully completed.Ultra-low background fast neutron detectors,4π BGO detector arrays and large solid angle particle detector arrays were developed and assembled,and the background levels of the ground and CJPL were measured.In general,JUNA project smoothly completed the objectives set in the medium term and passed the assessment of the fund committee (Grade A) and international assessment.