受限于反应截面低、裂变截面大等因素，运用传统的在束γ探测技术来研究重核近滴线区域原子核的高自旋态结构性质已经不现实。本项目将联合充气反冲谱仪装置，采用国际上新兴的反冲衰变标记（RDT）实验技术，首次探测^{217}Pa核的激发态能级结构，同时搜寻其可能新存在的同核异能态并提取相应的能级寿命，着重寻找Z=92亚壳结构是否存在的实验证据。RDT技术具有强大的反应道筛选能力，可有效地从高本底中挑选出目标核的信息，弥补了传统测量技术的缺陷。此外，实验中还将通过α—γ符合测量技术，探测^{217}Pa核α衰变的精细结构信息，完善^{213}Ac核低自旋态的能级纲图。根据实验结果，在壳模型等理论框架下，提取该核区价核子之间，价核子与核芯之间相互作用的信息，深入研究质子壳层结构在Z=82以上的演化性质。

Experiments are hampered by the low production cross sections and high fission probability for the nuclei around drip-line region, putting severe limits on the ability to bring the arsenal of in-beam spectroscopy to bear. In this work, the recoil-decay tagging (RDT) technique coupled to the gas-filled recoil separator will be applied to detect the excited states of ^{217}Pa. Moreover, we will search for the new isomer state of ^{217}Pa and measure its lifetime in the experiment. Based on the level structure of ^{217}Pa, the evidence for discerning the Z=92 subshell closure whether exists or not will be discussed. The highly selective RDT technique allows very weak reaction channels to be resolved from the large background due to fission and other competing processes. In order to establish the new level scheme of ^{213}Ac at low spin states, fine structure in the alpha-decay of ^{217}Pa will be detected through the α—γ correlation measurement. According to the experimental results, the information of the interplay between the particles and the corresponding core, and between the particles will be obtained by the theoretical calculation. This work is very helpful for exploring the evolution of proton shell structure beyond Z=82.