权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Lifetime measurements in heavy elements using the charge plunger technique

使用充电柱塞技术测量重元素的寿命

基本信息

批准号：
2601438
负责人：
金额：
--
依托单位：
University of Liverpool
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2021
资助国家：
英国
起止时间：
2021 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2601438
关键词：
Lifetime measurements heavy elements using

项目摘要

This research aims to measure lifetimes of heavy nuclei using the recently commissioned charge plunger device at the University of Jyväskylä Accelerator Laboratory. Lifetime measurements in heavy elements with large internal conversion coefficients prove difficult using standard plunger techniques, due to the reliance on the detection of Doppler shifted gamma-rays produced in nuclear decays at different velocity regions (before and after a degrader foil). A complementary approach for nuclei with high internal conversion coefficients is the charge plunger technique; a modification of the standard recoil distance Doppler-shift (RDDS) method, the technique utilises a charge reset foil, whereby the charge of ions is reset to a value dependent on their velocity. Once produced in fusion-evaporation reactions at a target, recoiling nuclei that decay via internal conversion may subsequently have their ionic charge increased due to the Auger effect. Varying the target-to-foil distance allows for the sensitivity of nuclear lifetimes to be probed, by counting the number of conversion events that occurred before and after the reset foil. The resulting charge shape distribution of recoil ions reflect the processes that occurred during their time of flight and allows for nuclear lifetimes to be extracted using the differential decay curve method (DDCM), or by fitting Bateman equations to the data. This research aims to make the first measurements of the lifetime of a non-isomeric state in No-254 (and possibly other transfermium nuclei) by employing the charge plunger technique described above.

这项研究旨在使用于韦斯屈莱大学加速器实验室最近调试的电荷柱塞装置来测量重核的寿命。事实证明，使用标准柱塞技术测量具有大内部转换系数的重元素的寿命很困难，因为依赖于检测不同速度区域（降解器箔之前和之后）的核衰变中产生的多普勒频移伽马射线。对于具有高内部转换系数的原子核的一种补充方法是电荷柱塞技术；该技术是对标准反冲距离多普勒频移 (RDDS) 方法的修改，利用电荷重置箔，将离子的电荷重置为取决于其速度的值。一旦在目标处的聚变蒸发反应中产生，通过内转换衰变的反冲核随后可能由于俄歇效应而增加其离子电荷。通过计算重置箔之前和之后发生的转换事件的数量，改变目标到箔的距离可以探测核寿命的灵敏度。由此产生的反冲离子电荷形状分布反映了其飞行期间发生的过程，并允许使用微分衰减曲线法 (DDCM) 或通过将贝特曼方程拟合到数据来提取核寿命。本研究旨在通过采用上述充电柱塞技术，首次测量 No-254（以及可能的其他转移m核）中非异构态的寿命。