Double Penning Trap Mass Spectrometer for Direct Gamma-Ray Standard Calibrations, Determination of Fundamental Constants, and Tests of Special Relativity

用于直接伽马射线标准校准、基本常数测定和狭义相对论测试的双潘宁阱质谱仪

• 批准号: 1307233
• 负责人: Matthew Redshaw
• 金额: $ 12万
• 依托单位: Central Michigan University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1307233&HistoricalAwards=false
• 关键词: Double; Penning; Trap; Mass; Spectrometer

Einstein's famous relation E=mc^2 expresses the equivalence of mass and energy and is one of the most well-known formulae in physics. It is a consequence of the theory of special relativity. A direct test of E=mc^2 can be performed by comparing the mass difference between two nuclear states to the energy that is released when a transition between those two states occurs. In this research we will measure the mass difference between two isotopes of chlorine, 35Cl and 36Cl, and compare it to the result of precise gamma ray spectroscopy measurements of the energy released after 35Cl captures a neutron. The atomic masses of 35Cl and 36Cl will be determined using Penning trap mass spectrometry, in which the mass of an ion is measured via the frequency of its motions in a combined magnetic and electric field. At Central Michigan University (CMU) a novel double Penning trap will be constructed and housed inside a 12 tesla superconducting magnet. This apparatus will be used to perform measurements on pairs of ions stored in two identical traps, which will enable the effect of magnetic field variations to be reduced. A comparison of the 35Cl and 36Cl mass difference with the gamma-ray spectroscopy energy measurement will also enable a calibration of gamma-ray energy standards used by detectors in nuclear physics applications in terms of atomic masses. In addition, it can be used to provide a precise determination of two important fundamental constants of nature: the Molar Planck constant and the fine structure constant, and could impact experimental data required for a possible redefinition of the kilogram.The research program under development at CMU will provide training of Masters and undergraduate students who will gain research experience in modern experimental atomic and nuclear physics techniques, creating an avenue for them to go on to pursue a Ph.D. or enter positions in the technical workforce. The CMU Penning trap will use ions produced by an external ion source and injected into the trap. This will enable many additional precision mass measurements to be performed on a wide range of isotopes, such as those with very low natural abundances, and long-lived radioactive isotopes and isomers, with applications in atomic, nuclear and neutrino physics. The techniques being developed could impact other high sensitivity mass spectrometry applications such as the single-ion Penning trap for rare-isotopes under development at nearby Michigan State University, and mass spectrometers used in national security applications for trace chemical detection.

爱因斯坦著名的关系式E=mc^2表达了质量和能量的等价性，是物理学中最著名的公式之一。这是狭义相对论的一个推论。E=mc^2的直接检验可以通过比较两个原子核态之间的质量差与这两个原子核态之间发生跃迁时释放的能量来进行。在这项研究中，我们将测量氯的两种同位素35Cl和36Cl之间的质量差，并将其与35Cl捕获中子后释放的能量的精确伽马射线光谱测量结果进行比较。35Cl和36Cl的原子质量将使用潘宁阱质谱法测定，其中离子的质量通过其在磁场和电场组合中的运动频率来测量。在中密歇根大学（CMU），一种新型的双潘宁陷阱将被建造并安置在一个12特斯拉的超导磁体中。该装置将用于对存储在两个相同阱中的离子对进行测量，这将能够减少磁场变化的影响。35Cl和36Cl质量差与伽马射线光谱能量测量的比较也将使得能够在原子质量方面校准由核物理应用中的探测器使用的伽马射线能量标准。此外，它还可以用来精确测定两个重要的自然基本常数：摩尔普朗克常数和精细结构常数，并可能影响可能重新定义千克所需的实验数据。CMU正在开发的研究计划将提供硕士和本科生的培训，他们将获得现代实验原子和核物理技术的研究经验，为他们继续攻读博士学位创造了一条途径。或进入技术工作岗位。CMU潘宁阱将使用由外部离子源产生并注入阱中的离子。这将使人们能够对各种同位素进行许多额外的精确质量测量，例如自然丰度非常低的同位素以及长寿命放射性同位素和异构体，并应用于原子、核和中微子物理学。正在开发的技术可能会影响其他高灵敏度质谱应用，例如附近密歇根州立大学正在开发的用于稀有同位素的单离子潘宁阱，以及用于国家安全应用的痕量化学品检测的质谱仪。