相关实验视频
Updated: Jun 19, 2025

08:53
Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures
Published on: October 9, 2012
17.6K
通过3n和3p系统的精确光谱 ^{3}H(t, ^{3}He) 3n和 ^{3}He(^{3}He, t) 3p反应在中间能量
K Miki1,2, K Kameya1,2, D Sakai1,2
1Department of Physics, <a href="https://ror.org/01dq60k83">Tohoku University</a>, Sendai 980-8578, Japan.
Physical review letters
|July 23, 2024
概括
研究人员使用核反应在三体系统中寻找低能共振结构. 实验没有发现明显的峰值,这表明存在相关性,但对共振来说不够强.
科学领域:
- 核物理 核物理 核物理
- 量子力学就是量子力学.
- 少数体系统 (Few-Body Systems) 是一个多体系统.
背景情况:
- 研究少数体核系统中的共振结构对于理解核力至关重要.
- 异T=3/2系统为研究三体相互作用提供了一个独特的探针.
- 之前对类似系统的研究,如四中子子,已经显示出明显的共振峰值.
研究的目的:
- 在同轴T=3/2三体系统中寻找低能共振结构.
- 在特定的核反应中探索三个中子 (3n) 和三个质子 (3p) 的行为.
- 为了比较实验发现与理论预测三体相关性.
主要方法:
- 进行了核反应实验: ^{3}H(t,^{3}He) 3n和 ^{3}He(^{3}He,t) 3p.
- 利用一种新开发的厚型Ti-^{3}H标,提高了的厚度.
- 覆盖了一个低动量转移区域,低至15 MeV/c,以实现脆弱系统的最佳生产.
主要成果:
- 在3n和3p系统的激发能量光谱中没有观察到明显的共振峰结构.
- 观察到的3n和3p的光谱分布相似,主要因库伦排斥效应而有所不同.
- 实验结果与四中子子谱中的观测结果形成鲜明对比.
结论:
- 这些实验没有在研究的同位素T=3/2三体系统中提供低能共振状态的证据.
- 虽然与理论的比较表明了三体相关性,但它们不足以形成共振峰值.
- 需要进一步的理论和实验研究才能充分理解这些少数体系统.
相关概念视频
UV–Vis Spectroscopy: Molecular Electronic Transitions
1.4K
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this...
1.4K
¹H NMR: Interpreting Distorted and Overlapping Signals
1.0K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.0K
Atomic Spectroscopy: Absorption, Emission, and Fluorescence
849
Atomic spectroscopy is a vital tool in elemental analysis, both qualitatively and quantitatively. It can be broadly divided into optical spectroscopy, mass spectroscopy, and X-ray spectroscopy methods. The optical spectroscopic methods are atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), and atomic fluorescence spectroscopy (AFS). The first step in all three methods is atomization, where the solid, liquid, or solution-phase samples are converted into gas-phase atoms and...
849
Molecular Spectroscopy: Absorption and Emission
2.0K
Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational and vibrational energy levels. Each energy level is separated by an energy gap, with the gaps between adjacent electronic, vibrational, and rotational levels varying significantly. The three types of energy levels in a diatomic molecule are shown in Figure 1.
2.0K
UV–Vis Spectroscopy of Conjugated Systems
6.9K
Organic compounds with conjugated double bonds show strong absorption features in the UV–visible region of the electromagnetic spectrum attributed to π → π* electronic excitations. Generally, a UV–vis absorption spectrum is recorded as a plot of absorbance vs wavelength. The wavelength of maximum absorbance, which manifests as a peak in the absorption spectrum, is denoted as λmax.
One of the factors influencing λmax is the extent...
One of the factors influencing λmax is the extent...
6.9K
¹³C NMR: ¹H–¹³C Decoupling
1.1K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.1K

