物理研究项目2022
阿米娜艾哈迈德
指导老师:David Schaffner
电磁学模块的等离子体
从等离子体物理实验中收集的数据可以用多种方法进行分析. The most efficient way to analyze raw plasma data is by running it through code which is equipped with the functionality to perform complex calculations. PlasmaPy is an opensource software ecosystem which provides a collection of the functionality needed by plasma physicists.
我的项目包括编写一个磁分析模块. 它还增加了计算磁场等功能, 应用带通滤波器, 意思是减法. The aim is for the magnetics module to be added to the PlasmaPy for others in the community to be able to use.
麦克斯韦Brenton
指导老师:David Schaffner
The 布林莫尔实验 (BMX) produces a confined plasma plume that can provide us with data on the behavior of plasma. 布林莫尔实验测量的变量之一是磁场. 利用实验中磁场随时间变化的柱坐标数据, I calculated the change in angle between two magnetic field vectors over a time interval of one unit. I made a histogram of the angles that I collected in order to observe the distribution of those changes in angle. The distribution of the resulting histogram could be used to make further observations about the behavior of the plasma.
姜奎妮和凯瑟琳·奥普萨尔
指导老师:Michael Noel
Rubidium 85 atoms in a magneto-optical trap (MOT) can be excited into states with high principal quantum numbers n, 或者里德堡态, 使用激光光谱学. Resonant energy exchange among these ultracold Rydberg atoms has been used in quantum computing, 量子模拟, 以及对封闭量子系统动力学的研究. Prior studies of dipole-dipole interaction have focused on systems with few initial and final states. We have observed interactions among atoms excited to states within the Stark manifold using an electric field. The harmonic nature and large number of states in the manifold allow for rich dynamics in this energy exchange process.
茱莉亚·莫伊伦·
指导老师:David Schaffner
布林莫尔实验
在布林莫尔实验(BMX)中, a plasma plume is sent through a cylindrical chamber with probes arranged along the axial direction. 随着羽流的移动，等离子体的磁场强度也在变化. Looking at the intermittency in the magnitude of the magnetic field can indicate magnetic reconnection in the plasma. This is done using a histogram depicting a probability distribution function (PDF) of the incremental differences in magnetic field magnitude. Large tails on the Gaussian curve fit to this histogram could be an indication of the presence of magnetic reconnection. When paired with an analysis of the intermittency in the direction of the magnetic field, this analysis can provide insight into whether the plasma plumes have magnetic field lines that are connected to the plasma source. 这个问题同样存在于来自恒星的等离子体太阳风中.
阿米莉亚史蒂文斯
指导老师:David Schaffner
BMX磁场波动的指数谱
The fluctuating magnetic field within a flowing plasma on the 布林莫尔实验 is measured. The fluctuations in time series are decomposed using a Fast Fourier Transform (FFT) and plotted in semi-log form.” The slope of linear fits of the semi-log spectra map to an exponential function of the form e^(-omega*tau). It turns out that the inverse transform of this exponential function takes the form of a Lorentzian function of the form: tau^2/(t^2 + tau^2). The original fluctuations are compared to these Lorentzian structures to see if they are of similar size. 如果是这样，这表明磁波动在起源上是混沌的.
伊丽莎白·汤普金斯
指导老师:Michael Noel
激发原子到里德伯态以观察远距离偶极-偶极相互作用
We can trap and cool rubidium atoms by manipulating wavelengths and frequencies of lasers as well as by applying electric and magnetic fields to the atoms. 当原子被捕获时, 然后我们用不同波长的激光将铷原子激发到里德伯态. Once at these Rydberg states the atoms have principal quantum numbers that are very high (n=30) causing them to be weakly bound. This weakly bound state allows the atoms to exhibit exaggerated properties that result in long-range dipole-dipole interaction. This long-range interaction allows atoms to exchange energy and interact with one another even when separated by distances of several microns. We will be building the optical apparatus to produce a system that will conduct the trapping and excitation described above. We then can then observe and measure long-range dipole-dipole interaction between atoms.
玛丽Wisz
指导老师:凯瑟琳·丹尼尔和凯伦·马斯特斯
螺旋螺距角对恒星径向迁移的影响
As galaxies evolve over time, the orbits of their constituent stars change in size and shape. These two characteristics can be probed in tracer particle simulations of spiral galaxies via the initial and final measures of stellar populations that track the orbital eccentricity and angular momentum of individual stars over time. We investigate how these two characteristics of orbital patterns are influenced by spiral arm pitch angle with a focus on how stars move near the corotation resonance of a spiral pattern. For all pitch angles we find that there are changes in both orbital eccentricity and size for stars across a wide radial range of the galaxy, 在不同的尺度上. 理论上的期望是，只有轨道的大小会在旋转时发生变化. This project is in process and will examine trends in these orbital changes around corotation for several pitch angles. 我们的目标是利用MaNGA和Galaxy Zoo的数据对相关措施进行观测探索. In observed galaxies we cannot access orbital parameters directly so we will look at how the metallicity gradient of spiral galaxies changes with pitch angle. 因为预计星系的形成会有一个显著的金属丰度梯度, 这一梯度的平坦化可以用来探测径向偏移. This research will help to further understand the dynamical evolution of galaxies and the impact of spiral arms on radial migration.