Lifetimes of low-spin excitations in the A=100 mass region

尽管多体量子系统很复杂，但原子核表现出的激发具有相当简单的结构。这包括例如核表面的集体振动或形状共存，即核的基态和激发态的不同形状。为了更深入地理解，一个非常重要的观测数据是这些激发的寿命。然而，对寿命的绝对测量带来了许多实验挑战，而且与理论相比较的数据相当匮乏。我们通过测量用于激发原子核的弹丸以及衰变过程中发射的伽马射线来改进所谓的DSA技术。这使我们能够在一次实验中提取多个激发的可靠寿命。在这个项目中，我们计划研究魔力Z=50壳层附近的原子核。在这些核中，上述许多特征都是可以预料到的。

Atomic nuclei show excitations which have - despite the complexity of the many-body quantum system - rather simple structures. This includes, e.g., collective vibrations of the nuclear surface or shape coexistence, i.e., different shapes of the ground state and excited states of a nucleus. One very important observable to get a deeper understanding is the lifetime of these excitations. However, an absolute measurement of lifetimes poses many experimental challenges and data for a comparison with theory is rather scarce.We have improved the so-called DSA technique by measuring the projectile which has been used to excite the nucleus as well as the gamma rays which are emitted during the decay. This allows us to extract reliable lifetimes for a number of excitations in a single experiment. In this project, we plan to investigate nuclei near the magic Z=50 shell. In those nuclei many of the features described above are expected.