相关实验视频
Updated: Jun 19, 2025

10:42
Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh
Published on: May 3, 2019
6.7K
在固态宿主中激光激发^{229}Th核同位素过渡
R Elwell1, Christian Schneider1, Justin Jeet1
1Department of Physics and Astronomy, <a href="https://ror.org/046rm7j60">University of California</a>, Los Angeles, California 90095, USA.
Physical review letters
|July 23, 2024
概括
研究人员使用激光光谱对-229的化晶体,以找到核异构转换. 观察到一个狭窄的光谱特征,证实了-229核同位素的激发.
科学领域:
- 核物理 核物理 核物理
- 激光光谱学 激光光谱学
- 材料科学 材料科学 材料科学
背景情况:
- -229 (229Th) 的核异构过渡由于其潜在的应用而引起了极大的兴趣.
- 之前的研究旨在准确地描述229Th核同位素的能量和特性.
- 电化 (LiSrAlF6) 晶体为229Th兴奋剂提供了一个有前途的宿主矩阵.
研究的目的:
- 通过激光搜索229Th的核同位素过渡.
- 准确确定一个LiSrAlF6晶体内的229Th核异构体状态的能量和衰变特性.
主要方法:
- 使用了用229Th.doped的LiSrAlF6晶体上的激光光谱学.
- 在预测的核过渡能量附近观察和分析了光谱特征.
- 测量了观测特征的光谱线宽,光和衰变寿命.
主要成果:
- 确定了两个不同的光谱特征:带有红移光的广泛激发和狭窄的光谱特征.
- 在148.38219纳米观察到的狭窄特征是激光线宽限制的,并被分配给229Th核异构体状态的激发.
- 确定229Th:LiSrAlF6中229Th核异构体状态的能量为8.355733 eV,衰变寿命为568秒.
结论:
- 这项研究成功地通过激光光谱学在LiSrAlF6.6中识别和表征了229Th核同位素过渡.
- 精确的能量和寿命测量为理解和潜在地利用229Th同位素提供了关键数据.
- 这项工作代表了利用229Th核异构体用于技术应用的重要一步.
相关概念视频
Atomic Nuclei: Nuclear Relaxation Processes
643
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
643
Nuclear Transmutation
17.5K
Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen-14 atoms with high-speed α particles from a natural radioactive isotope of radium and observed...
17.5K
Deactivation Processes: Jablonski Diagram
626
Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...
626
Atomic Nuclei: Magnetic Resonance
643
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
643
Atomic Nuclei: Nuclear Spin State Population Distribution
971
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
971
Atomic Emission Spectroscopy: Instrumentation
356
The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers. Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
356

