论文标题
使用低能二进制重型离子反应的数十亿美元的飞秒核国家寿命
Accessing tens-to-hundreds femtoseconds nuclear state lifetimes with low-energy binary heavy-ion reactions
论文作者
论文摘要
已经开发了一种新型的蒙特卡洛技术，以确定数十百秒秒范围内激发状态的生命。该方法适用于具有复杂速度分布的低能重型离子二元反应。与$^{18} $ O（7.0 meV/u）+$^{181} $ ta实验相关的相关性，该实验在Ganil上与Agata+Vamos+Paris设置一起进行，以研究中子富含中子的O，C，n，... nuclei。 $^{17} $ O和$^{19} $ O中的激发状态（具有已知寿命）用于验证该方法在$ \ sim $ 20-400 $ 20-400 FS寿命敏感范围内。重点是由$γ$跟踪阵列提供的前所未有的位置分辨率，事实证明，这对于在$γ$ - 射线线路的详细分析和结果状态生命周期确定的基础上，对于达到多普勒切换校正所需的准确性至关重要。预计该技术是用强烈的隔离型束产生的外来富含中子核的终生研究的重要工具。
A novel Monte Carlo technique has been developed to determine lifetimes of excited states in the tens-to-hundreds femtoseconds range. The method is applied to low-energy heavy-ion binary reactions populating nuclei with complex velocity distributions. Its relevance is demonstrated in connection with the $^{18}$O(7.0 MeV/u) + $^{181}$Ta experiment, performed at GANIL with the AGATA+VAMOS+PARIS setup, to study neutron-rich O, C, N, ... nuclei. Excited states in $^{17}$O and $^{19}$O, with known lifetimes, are used to validate the method over the $\sim$20-400 fs lifetime-sensitivity range. Emphasis is given to the unprecedented position resolution provided by $γ$-tracking arrays, which turns out to be essential for reaching the required accuracy in Doppler-shift correction, at the basis of the detailed analysis of $γ$-ray lineshape and resulting state lifetime determination. The technique is anticipated to be an important tool for lifetime investigations in exotic neutron-rich nuclei, produced with intense ISOL-type beams.
