拟定中的RIBLL实验装置

Proposed Experimental Setups of RIBLL

建议在兰州放射性束流线（ Ｒ Ｉ Ｂ Ｌ Ｌ）上建设３ 套装置： 直接反应精细测量装置， 用来对放射性束的粒子的运动轨迹逐一进行跟踪， 以及对粒子的电荷态、核电荷数、质量数和能量进行精确跟踪， 从而得到核反应和核结构的准确信息； 磁谱探测系统， 它是由一个二极磁铁和相关真空室组成， 一方面它是一个谱仪系统， 用来分离原始放射性主束和次级反应产物， 进行粒子种类和能量的测量， 另一方面， 还可以用来研究放射性核的电磁矩和基态组态； 奇异衰变的４π探测装置是由５套大面积位置灵敏薄片硅探测器和 Ｃｓ Ｉ（ Ｔｌ）组成的望远镜组， 可覆盖整个探测空间的６０％ ～７０％ ，外加多个塑料中子探测器或 γ探测器， 用来测量奇异核和蒸发余核的关联粒子发射， 寻找和测量奇异的放射性衰变．

Radioactive Ion Beam Line in Lanzhou (RIBLL) is able to produce hundreds of radioactive ion beams, by mean of projectile fragmentation. A high performance setup for nuclear direct reaction was promoted to track the radioactive ion, and to measure its charge states, nuclear charge, mass, energy. It benefits precise experiment of both nuclear reaction and nuclear structure. An experimental magnet, composing by dipole magnet and vacuum chamber, should be used as magnetic spectrometer to separate the secondary beam and products of secondary reaction, as well as to analyze the particles and their energy. Using the magnetic field and method of β decay nuclear magnetic resonance, the studies of nuclear magnetic moment, electric quadruple moment and ground state configuration of radioactive nucleus could be performed. A mini 4π detection system, consisting of 5 large area position sensitive transmission silicon detectors (300 μ) backed by CsI(Tl) (2 cm) with detection efficiency of 60%～70% of full space, and surounded by an array of neutron sensitive plastic scintillator (5 cm×15 cm×15 cm) and γ detectors outside the vacuum, was employed to measure β delayed light particle emission coincidence with γ and neutrons for radioactive nucleus and evaporation residues, to search exotic decay mode, such as two protons decay and β delayed multi particle emissions.