REU 2016

Accelerator Physics

Faculty: Pietro Musumeci

The REU student will be involved in our research on electron sources for a novel application of ultrahigh brightness electron beams: time-resolved transmission electron microscopy.  The student will be actively involved in the experiments currently ongoing at the UCLA Pegasus advanced photoinjector Laboratory.

Astronomy

Faculty: Andrea Ghez

Project: Black Hole and Its Environment at the Galactic Center: High resolution images of the center of our Galaxy with the world's largest telescopes are giving us an unprecedented view of a supermassive black hole and its environs. Through precision measurement of stellar orbits we aim to address many fundamental questions about the formation and evolution of black holes and galaxies. Possible summer projects include studies of (1) how the observed young stars arrived in this region in which no young stars were expected, (2) how this region was depleted of giants, which were predicted to exist in large numbers, (3) searches for micro-lensing events and (4) simulations of observations with future large ground-based telescopes.
 
Faculty: Tuan Do

How do stars clusters form? How does the physics of star formation operate in different environments around the Milky Way? How long do star clusters last? By carefully examining very young star clusters through a combination of imaging and spectroscopy, we can help answer these questions. In this project you will be using data from the Keck telescopes to study the composition and dynamics of a young star cluster very soon after its formation.

Faculty: Steven Furlanetto/Jordan Mirocha

Radiative Feedback and the Formation of the First Stars in the Universe: While there is little evidence that the mass distribution of stars varies in nearby galaxies, there are compelling theoretical arguments that the very first stars to have formed in the Universe — which must have formed out of chemically pristine clouds — grew through qualitatively different mechanisms. This channel requires that a substantial fraction of hydrogen atoms reside in molecules, whose abundance is in part mediated by the radiation environment of the cloud. In this project, we will investigate the collapse of proto-stellar clouds that are subjected to a meta-galactic radiation background, i.e., one which is composed of photons originating from many galaxies at great distances. Because this radiation background can be constrained indirectly by forthcoming radio observatories, our work will provide an important link between future observations and the physics of the Universe's first galaxies.

Atomic, Molecular, and Optical Physics

Faculty: Wes Campbell

Project: Construction of a Narrow Linewidth Laser.  AMO physics has strict performance requirements for the lasers used to access transitions in cold atoms and molecules.  Typically, the frequency must be accurate and stable to a part in 10^8, which carries with it the requirement that thermal expansion and vibrations of the laser cavity itself must be carefully controlled and minimized.  An REU student will build an external-cavity diode laser for two-photon spectroscopy of rubidium, whose linewidth is about 1 part in 10^9 of its frequency.  This project will involve optics, electronics, and mechanical engineering.

Faculty: Paul Hamilton

Matter wave interferometry: The construction of a new type of atom inteferometer with direct detection of matter wave interference in an optical cavity.  This tool will enable high sensitivity, real-time measurements of forces and accelerations which will be used to search for proposed forms of dark matter.  This project involves work with vacuum systems, stabilized lasers, analog and digital electronics, laser cooling, cavity QED, and general control of quantum systems.

Beam Physics

Faculty: James Rosenzweig

A new free-electron laser and advanced accelerator laboratory funded by the Keck Foundation, SAMURAI, is being constructed at UCLA. The first experiments at this laboratory will utilize a multi-terawatt, <40 femtosecond laser system for two measurements: an initiative in coherent X-ray generation involving a new high harmonic generation mechanism from light-surface interactions; and an exploration of metallization of dielectrics at very high fields. Both of these scenarios involve electron behavior in strongly nonlinear limits, at multi-GV/m electric fields. They impact a variety of compelling applications, ranging from new light sources to ultra-compact laser-based accelerators.

Condensed Matter

Faculty: HongWen Jiang

Spin qubits in Si quantum dots: The REU student will participate a research to coherently manipulate and to characterize a qubit that is based on individual electron spins in Si quantum dots.  Such qubits have considerable potential for scalable quantum information processing.

Neurophysics

Faculty: Mayank Mehta

1) Hardware+software: Developing hardware and software to measure neural signals in natural and virtual reality from live rats.

2) Computation: Develop computational and theoretical techniques to decipher neural responses, and neural rhythms from the live brain of rats.

Research in our lab focuses on the rapidly emerging field of Neurophysics. The key question here is: How do large ensembles of neurons learn and remember information about the physical world? Recent advances in physics, computer science and neurobiology has put us much closer to addressing this fundamental and long standing question.  Our laboratory combines techniques from these diverse academic fields, including both experimental and theoretical approaches, to tackle this challenge.

Our recent research has focused on understanding how ensembles of neurons form a mental representation of space and time. To address this goal, we measure neural responses from freely behaving behaving rodents without causing much injury to their brain or health. To manipulate their perception of space and time we use state of the art virtual reality system for rats. We also study neural responses during sleep, which influence perception of space-time during behavior. We develop hardware and software to measure neural signals in natural and virtual reality, and we develop computational techniques to decipher the responses we measure in the laboratory and develop mathematical theories to understand the emergent neural dynamics.

Nuclear Physics

Faculty: Huan Z. Huang/Gang Wang

Project: Study of Heavy Quark Interaction with QCD Matter: QCD partonic matter at extremely high temperature and energy density has been created in Au+Au collisions at Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). We will study heavy quark (Charm and Bottom) interactions with the QCD matter in central Au+Au collisions. Heavy quarks are produced mostly through the gluon-gluon fusion process during the initial impact of the colliding nuclei. After the initial production heavy quarks may scatter off partons in the QCD matter and suffer energy losses while traversing the QCD matter via gluon radiation or elastic scattering. We will investigate experimentally signatures of these heavy quark interactions with the QCD matter.

Plasma Physics

Faculty: Neal Crocker

The National Spherical Torus eXperiment - Upgrade (NSTX-U) at the Princeton Physics Laboratory (PPPL) is a laboratory plasma device operated as part of a national collaboration to engage in plasma physics research that "may open an attractive path towards developing fusion energy as an abundant, safe, affordable and environmentally sound means of generating electricity." (http://nstx-u.pppl.gov)   My research focuses on how Alfvén waves excited by super-Alfvénic heating beams can cause the deposited heat to be transported through the plasma.  The project will consist of performing simulations of Alfvén waves excited by the beams and comparing with experimental observations in order to test theories for the excitation and properties of the waves.  This project will contribute to an ongoing effort to develop a predictive capability for the excitation of the waves and the heat transport they cause.

Faculty: Christoph Niemann

We will perform experiments with a 20 J laser system to study exploding plasmas in a preformed magnetic field and the formation of astrophysically relevant shock waves. The exploding laser plasma creates conditions that mimic astrophysical phenomena such as supernova explosions or coronal mass ejections. These experiments can help to shed some light on the origin of cosmic rays and the evolution of the particle distribution throughout the cosmos. The student will help develop and field electrical plasma probes to measure the magnetohydrodynamic response of the shock and help develop, and characterize a new pulsed liquid or gases hydrogen jet target using laser-interferometry.

Soft Condensed Matter

Faculty: Tom Mason

The topic that I have in mind is analyzing trajectories of probe particles and molecules in systems that exhibit both active and passive behavior for microrheology and imaging experiments. It’s a topic in soft condensed matter physics. The REU student would be doing computational/theoretical work using existing experimental data sets that we have, so this REU has direct applications to experiments but is computational in nature. A strong candidate would have programming experience (preference for Mathematica, Matlab, C/C++).

Theoretical Plasma Physics

Faculty: Frank Jenko

Most of the visible universe is in the forth state of matter, i.e., it is a plasma. And most of these plasmas are flowing in a turbulent fashion. Thus, it is not surprising that numerous phenomena in astrophysical systems, from the accretion of matter onto supermassive black holes to the acceleration and propagation of high-energy cosmic rays are dependent on our grasp of plasma turbulence. Recent spacecraft measurements in the solar wind pioneered the study of dissipation phenomena at the smallest scales, which help determine the thermodynamics of astrophysical plasmas and may involve the creation of energetic particles. The REU student will apply both analytical and numerical methods to characterize and better understand these phenomena.