Precision measurements with trapped radioactive ions using the Canadian Penning Trap Mass spectrometer and associated ion traps at the Argonne National Laboratory

使用阿贡国家实验室的加拿大彭宁阱质谱仪和相关离子阱对捕获的放射性离子进行精确测量

• 批准号: SAPPJ-2015-00034
• 负责人: Sharma, Kumar
• 金额: $ 10.2万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=614421
• 关键词: Precision; measurements; trapped; radioactive; ions

Precision measurements of the atomic masses of nuclides far from stability provide information on the energy released in the decay and nuclear reactions involving these exotic, short-lived, nuclei. The results are an important ingredient in predicting the rates and pathways of nuclear reactions that power explosive astrophysical events thought to be responsible for the nucleosynthesis of the heavier elements (through the rp-, nu-p- and r-processes). The data also provides a view of nuclear structure in regions where the nuclei have extreme neutron to proton ratios and, provide an opportunity for the study of fundamental symmetries in particle physics theories. Currently, The Canadian Penning Trap Mass Spectrometer (CPT) is being used to measure the masses of very neutron-rich isotopes that lie on or near the expected reaction path for the astrophysical r-process, a region that lies near the edge of nuclear stability called the "neutron dip line". The nuclei of interest are provided by the CARIBU (Californium Radioactive Ion Beam Upgrade) facility at the Argonne Tandem Linear Accelerator System (ATLAS) at the Argonne National Laboratory. The exotic, neutron-rich, atoms are produced by spontaneous fission, in a 1.7 Ci, 252Cf fission source and delivered (with a few keV of energy) to the CPT for a precise measurement of their mass. Alternately, the ions can also be transferred to a radio-frequency quadrupole ion trap (RFQ) where they are suspended in helium gas. Such a cloud of exotic nuclei, nearly at rest, provides a unique opportunity to study the correlations between the beta particles, the neutrinos and other particles emitted in their decay and test symmetries in particle physics theories. The amount requested will cover the operation and maintenance costs of the Canadian Penning Trap mass spectrometer (which is entirely Canadian owned), 3 graduate student stipends , the salary for a post-doctoral fellow and, travel costs to and from the facility. This work is carried out in collaboration with J. Clark and G. Savard, Physics Division, Argonne National Laboratory, Ralph Segel, Northwestern University, Nicholas Scielzo, Lawrence Livermore National Laboratory and Ani Aprahamian from Notre Dame University, all from the USA.

对远不稳定的核素的原子量的精确测量，提供了在衰变和涉及这些奇特的、寿命短的原子核的核反应中释放能量的信息。这些结果是预测核反应速率和途径的重要组成部分，核反应为爆炸天体物理事件提供动力，这些事件被认为是导致重元素核合成（通过rp-， nu-p-和r-过程）的原因。这些数据还提供了原子核具有极端中子质子比区域的核结构视图，并为粒子物理理论中的基本对称性研究提供了机会。