NSF REU in Interdisciplinary Materials Topics
Study and Characterization of Bismuth
Selenide (Bi2Se3)
William Serrano-García, Department of Physics Applied to Electronics, University of Puerto
Rico at Humacao
Joon Sue Lee, Anthony Richardella, Dr. Nitin Samarth, Department of Physics, Penn State
University
Bismuth Selenide has been shown to be a 3D topological
“insulator” with novel electronic surface states. This
project involves the characterization of Bi2Se3 thin films
(grown by Molecular Beam Epitaxy) via Atomic Force
Microscopy (AFM) and X‐Ray Diffraction (XRD). The
structural characteristics have been characterized with
XRD (a non‐destructive analytical technique which reveals
information about the crystal structure) to view the
diffraction pattern from the layered Se‐Bi‐Se‐Bi‐Se
structure of the crystal. This is called a quintuple layer
that is ≈1nm. AFM, with a resolution on the order of
fractions of a nanometer, gives an image of the sample
roughness due to quintuple layer steps on the surface. We
are looking forward to making better samples in the MBE
that have lower carrier concentration and high mobility by
improving the crystal structure and minimizing the surface
roughness. This new material promises new applications
in the fields of spintronics and quantum computation.
From left to right: Dr. Nitin Samarth and William Serrano working with the AFM used in this project. Chemical Vapor Deposition Growth of High
Quality Graphene with Suppressed Multilayers
Anna Skinner, Department of Physics, Virginia Tech
Junjie Wang and Jun Zhu, Department of Physics, Penn State University
Graphene, a two-dimensional allotrope of carbon,
displays unique opto-electronic, thermal, and
mechanical properties that have great potential for use
in electronics, both in industry and research.
Chemical vapor deposition (CVD) allows for production
of larger sheets of graphene than the alternative
exfoliation of graphite technique, as the size is only
limited by the size of the CVD equipment. For
applications in electronics, wafer-scale uniform sheets
of monolayer graphene with few defects are needed.
Our objective was to find a CVD formula that produces
high quality pristine graphene, meaning pristine
monolayer graphene with large domain sizes, small to
zero defect densities, and less than 5% multilayer
coverage.
Over the course of the summer, I successfully grew graphene in a newly set up CVD furnace system and
was able to transfer graphene sheets from the copper substrate on which they were grown to Si/SiO2
wafers. I used Raman spectroscopy to determine the quality of graphene, both before and after transfer.
SEM enabled me to determine the percent of multilayer coverage. My summer REU at Penn State
provided me with excellent research experience and hands-on lab skills, as well as opportunities to improve
my presentation skills. I was able to apply skills I have learned in classes and greatly expand upon my
knowledge of condensed matter physics and laboratory procedures and techniques.
Fabrication of Effective SERS Substrates for Diagnostic Testing
Brycen D. Kryzer, Department of Physics and Mathematics, St. Olaf College
Dr. Shikuan Yang, Dr. Tony J. Huang, Department of Engineering Sciences and Mechanics, Penn State University Trace detections of chemical and biological species are
critical in various fields involving diagnostics, drug
smuggling, antiterrorism, and environmental pollution
monitoring. Simple techniques that can synthesize
sensitive and reliable trace detections at a low cost are
highly desired. Surface Enhanced Raman Scattering
(SERS), which dates back to the 1970s, has grown as one
of the candidates in analytic and diagnostics applications
because of its specificity and high sensitivity (single
molecule probing). The major obstacle that hinders the
SERS technique as a viable commercial product is SERS
substrate design and its cost. Our research implements a
simple wet chemical method for the fabrication silver
octahedra as SERS substrates in a microfluidic channel.
We have achieved preliminary results using the organic
tracer dye Rhodamine 6g. In this study we found the SERS
enhancement to be quite significant.
I was responsible for the fabrication of the microfluidic channel as well as attaching the sliver octahedra to the surface.
This presented unique challenges because the SERS substrate is so sensitive to the surface conditions. This remains
the primary goal of this research: finding cost effective methods for fabrication of SERS/microfluidic platforms for
diagnostic testing. I thoroughly enjoyed this experience and look plan on continuing research at the graduate level.
Enzyme-powered micropumps
Jessica Soto, Department of Chemical Engineering, University of Puerto Rico-Mayagüez
Samudra Sengupta, Ayuman Sen, Department of Chemistry, Penn State University
An enzyme that moves by generating a
continuous surface force in a fluid should, when fixed
in place, function as a micropump. In this work we
fabricated four different enzyme‐powered pumps by
immobilizing enzymes on a gold surface patterned on
a PEG‐coated glass surface. The patterned surface
was functionalized with a quaternary ammonium
thiol, which forms a self‐assembled monolayer (SAM)
on the Au surface in which the enzyme binds
selectively. Fluid flow after substrate addition was
monitored
by
functionalized
polystyrene
microspheres as tracers using an optical microscope.
This project will have many applications in the future,
such
as drug
delivery, self‐assembly
of
superstructures, roving sensors among others.
Besides the applications of this project to the world of science, it will have an
impact in my future development, because I will be learning how to use important
techniques, that can be useful for my future plans to obtain a Ph.D.
Micropatterning of Conducting Polymer by Agarose Stamping and Electrodeposition
Samantha R. Corber1,2
1Department of Chemistry, 2Department of Physics, Washburn University
Kelly N. Layton3, Erin Richards3, Prof. Mohammad Reza Abidian3,4,5
3Department of Bioengineering, 4Department of Chemical Engineering, 5Department of Material Science and
Engineering, The Pennsylvania State University
Organic conducting polymers (CP) such as poly(pyrrole) (PPy) are of
particular interest in neural engineering due to their semiconductor-like
electrical properties, polymeric mechanical properties, and
biocompatibility. Further, these polymers have the capability to act as
tunable drug delivery systems to neural tissue by incorporation of a drug
during electrodeposition of the polymer on a conductive substrate and
release by actuation of the drug-loaded film. Recently, new methods
have been developed to micropattern CP on a substrate using a two-step
process that consists of complete coverage of the substrate with the CP
followed by selective oxidation of the polymer to limit the area capable
of conducting a current. Because these methods limit the applications to
those only needing a single type of polymer, dopant and drug, the aim of
this project is to develop and characterize a simple one-step method of
electropolymerization using patterned agarose stamping.
During my project this summer, I began characterizing this method by impedance
spectroscopy, optical imaging and Scanning Electron Microscopy. I was able to
experience applied materials research first hand at a large university. This project not
only helped me decide that this is the field of science I wish to pursue, but also gave me
experience that will be invaluable in my future career.
Highly Accelerated Lifetime Testing (HALT) and Reliability Analysis
of Niobium Doped Lead Zirconate Titanate (PZT) Thin Films
Casey Newell, Department of Physics, University of Massachusetts Dartmouth
Lauren Garten, Dr. Susan Trolier-McKinstry, Department of Materials Science and Engineering, Penn State
University
The lifetime and reliability of piezoelectric thin films is critical to
developing a wide variety of piezoelectric microelectromechanical
systems (MEMS), such as: actuators, sensors, and millimeter size
robotics. The purpose of this study was to understand the factors
affecting reliability of 1% by mole niobium doped lead zirconate
titanate Pb(Zr,Ti)O3 (PZT) thin films. To determine reliability, the
thin films were subjected to a highly accelerated lifetime test
(HALT) which consists of applying voltage, beyond what the
material would see in application, across the film under increased
temperatures, and measuring leakage current as a function of
time. Failure of the films occurs when the leakage current
increases to a point that is set based on the specific application.
The time to failure is then used to determine the electric field and
temperature dependence of the degradation in the material. By
fitting this data to known conduction models the likely carrier type,
and the conduction and failure mechanisms can be extracted.
My role in the project was to prepare the PZT samples, do
electrical characterization, run the HALT, and perform data
analysis. The research project this summer gave me a breadth of
experience. Working in materials science, a field I had never even
considered, exposed to me to a combination of physics and
chemistry that I was previously unaware of. Overall this project
was a positive learning experience that will help me achieve my
future goals.
MOKE Imaging of Magnetic Domains in
Thin Multilayer Pt/Co Films
Kerry Ryan1, Robbie Fraleigh2 and Nitin Samarth2
1Department of Physics, The College of New Jersey; 2Department of Physics, Penn State University
Understanding magnetic domain switching behavior is essential for applications in nanomagnetic
logic and memory devices. Magneto‐optical Kerr effect (MOKE) reflectometry is a well‐known noninvasive technique to observe the magnetic switching behavior with resolution restricted to the length scale of the beam spot size. With the addition of a CCD camera and objective lens to the experimental setup, our study extended MOKE reflectometry to an imaging setup that spatio‐temporally resolved the dynamic behavior of magnetic domains in thin multilayer films.
By interfacing the MOKE setup with LabView , we investigated the effects of changing the polarization angle, electronic manipulation of images, and averaging of images to produce sharp, clear images of domain structures. We also analyzed the relationship between ramp rate and coercive field. As my first research experience, this project was extremely beneficial to me. I learned new research techniques and programming languages. Most importantly, I realized I enjoy working in a laboratory environment and would be interested Domains in a thin multilayer Pt/Co film
in doing so in the future.
Synthesis of Superconducting-Ferromagnetic
Segmented Sn/Co/Sn Nanowires
Jaylissa Torres Robles, Department of Chemistry, University of Puerto Rico-Cayey
Dr. Weiwei Zhao, Dr Meenakshi Singh, Dr. Moses Hung-Wai Chan, Department of Physics, Penn
State University
Many types of nanowires have been synthesized to study basic
science in low-dimensional systems. Earlier experiments on
electrodeposited ferromagnetic Co and Ni nanowires have shown an
unexpectedly induced long range superconducting proximity effect on a
ferromagnet. The goal of this project is to synthesize and characterize
segmented superconducting/ferromagnetic (S/F) nanowires to see if the
long range proximity effect persists in these geometry. In this project I grew
segmented superconducting- ferromagnetic nanowires.
I used a technique named template based electrodeposition to
grow the nanowires using ther electrolyte salts. The structure and
morphology of the nanowires was studied using transmission electron
microscopy. Electrical transport measurements will be made on these
nanowires to attempt to see the long range proximity effect. The
electrical transport results will shed light on the role of the interface in
the long range proximity effect in ferromagnetic nanowires. This Project
has given me the real perspective of being a researcher and scientist. It is
also been an opportunity to discover new topics that I may be interested
in to continue on grad school.
Synthesis and Characterization of Boron‐Doped Carbon Nanotube Sponges
Platte Gruber, Department of Physics, Nebraska Wesleyan University
Lakshmy Pulickal Rajukumar, Dr. Ana Laura Elías, Prof. Mauricio Terrones, Department of Physics,
Penn State University
Carbon Nanotubes (CNTs) provide a foundation upon which
new, unique materials are able to be developed. CNT sponges consist
of tridimensional structures that are highly porous (360 m2/g), light
weight (10‐30 mg/cm3), hydrophobic and oleophilic. These sponges
have particularly interesting application potentials in oil spill cleanup
and as polymer additives. For their synthesis, an aerosol‐assisted
Chemical Vapor Deposition (AA‐CVD) method was used, in which a
hydrocarbon, iron catalyst and a boron source in solution is vaporized
and directed inside a quartz tube located in a furnace operating at
high temperatures (800‐900 °C). Here, we sought to optimize and
improve upon this process of synthesizing boron‐doped multi‐walled
CNT (CBx MWNTs) sponges.
My research this summer focused on the development of a
novel material rooted in the new morphologies of carbon, in this case
carbon nanotubes. The opportunity to work with and learn from such
an accomplished group this summer afforded me an invaluable
experience. It took me beyond the classroom, and has had a profound
impact on me as student and developing scientist.
Electron transport under soft confinement in
organic semiconductor mixtures
Omar Padilla Vélez, Department of Chemistry, University of Puerto Rico - Cayey
Enrique D. Gomez, Department of Chemical Engeneering, Penn State University
Organic semiconductors have the potential of being used in the development of
new flexible electronics at a lower cost than conventional transistors. One drawback of
organic materials, however, is the low electron mobility when compared to silicon-based
devices. In an effort to enhance our understanding of the basic processes which govern
transport in organic materials, this project is focused on measuring charge transport
through mixtures of organic semiconductors.
In particular, I studied electron
transport under soft confinement in mixtures
of poly(3-hexylthiophene) (P3HT) and phenylC60-butyric acid methyl ester (PCBM). By
fabricating and testing organic thin film
transistors (OTFTs) I obtained estimates of the
charge mobility and my results suggested that
transport is confined to two dimensions
following the concepts of percolation theory.
This project has given me the overall
experience of graduate research and helped me
develop my skills as a future scientist.
Transparent Schottky Barriers for Light
Emitting Diodes
Morgen Patterson, Department of Physics, Mount Holyoke College
Michael Abraham, Won Choi, Dr. Suzanne Mohney, Department of Materials Science and
Engineering, Penn State University
White light emitting diodes (LEDs) have enormous
potential to become the next source of general illumination.
By utilizing Schottky barriers we would also have the added
advantage of fast switching. Fast switching times would
allow these LEDs to be used for wireless transmission, in
addition to general illumination. This study was conducted to
create an optimized Schottky contact, between n-GaN and
Indium Tin Oxide (ITO), by increasing the Schottky barrier
height for a better performance LED, while still retaining the
ITO’s transparent properties.
This summer, I created a number of samples using
an e-beam evaporation system. I tested these samples for
their current-voltage (I-V) relations and used this data to
determine the ideality factor and barrier height. To improve
the as-deposited samples, I tried annealing and adding and
interfacial Ni layer. All of these methods showed varying
levels of success, giving this project the potential to move
forward into actual LED creation.
This project has been very beneficial to my
understanding of electromagnetic properties and vastly
increased my research abilities. I can now confidently say
that I will be following a career to physics research and move
forward with research at school with more confidence and
skill.
Low Temperature Elastic and Piezoelectric
Properties of Lithium Niobate
Kellan Euerle, Department of Physics, Gustavus Adolphus College
Dr. J. D. Maynard, Department of Physics, Penn State University
Professor J.D. Maynard is working on compiling full temperature range material property data on a selection of engineering materials. This data will go into a computer program which would expedite the selection process of materials being used to create energy recycling devices. This study was conducted to measure the elastic and piezoelectric properties of LiNbO3 at a range from room temperature to liquid helium temperature. The elastic properties of LiNbO3 are measured using RUS (resonant ultrasound spectroscopy). In this method, one measures the natural frequencies of vibration for a sample’s normal modes. By processing these frequencies with the shape and mass of the sample in a computer, it is possible to determine all of the elastic constants of a material. Due to the piezoelectric properties of LiNbO3, the effects of piezoelectric‐elastic coupling must be included in these calculations. A RUS apparatus was constructed and was proven to function at room temperature. The apparatus was then fitted to a low temperature set‐up. Frequencies for the LiNbO3 sample’s normal modes were successfully recorded at temperatures down to liquid nitrogen temperature levels. I worked specifically on designing and building the RUS apparatus. I also tested and made adjustments to the apparatus in order so that it functioned properly. Once the apparatus was functioning, I ran trials at a range of temperatures for a Lithium Niobate
sample, and recorded its resonant frequencies. This research gave me the opportunity to gain a great deal of experience in the lab and working with a professor, which I would not have had coming from a small liberal arts school. It also exposed me to many areas of research and interesting projects which will aid me in making a decision about the kind of research I want to go into.
Oxidation of Bismuth Selenide Thin Films
Malia L. Kawamura1, Joseph E. Brom2 and Dr. Joan M. Redwing2,3
1Department
of Physics and Mathematics, Colby College; 2Department of Materials Science,
Penn State University; 3Materials Research Institute, Penn State University
Bi2Se3 displays characteristics of a topological
insulator (TI) with a relatively large band gap (0.3 eV)
compared to other TI materials. To study the protected
surface states of Bi2Se3 high quality crystals with low
carrier concentrations are required so the surface states
can be studied independently of bulk conductivity.
Bi2Se3 is important for future applications in electronic
devices, quantum computing, spintronics, optics, along
with other possibilities.
I performed Hall Effect system measurements on
Bi2Se3 thin films grown on (001) Al2O3 by the hybrid
physical chemical vapor deposition (HPCVD) technique.
I studied the changes in electrical properties as
functions of time and different ambient environments
(air, H2O, N2) to determine the mechanism responsible for the degradation of electrical
properties. Additionally, I investigated whether annealing in a Se-rich environment could
reverse the loss of quality by filling Se vacancies. I gained direct experience working in a
laboratory, conducting research, and participating as a member of a research group. I now
have a much more comprehensive idea what graduate school is like and the breadth of
interesting interdisciplinary research projects.
Ferroelectric Polarization Switching in a
Multiferroic Tunnel Junction
Joseph H. Kwasizur, Department of Physics, Lafayette College
Gregory J. Harkay, Dr. Qi Li, Department of Physics, Penn State University
Multiferroic tunnel junctions are thin films consisting of two ferromagnetic (FM) conducting layers with a thin ferroelectric (FE) insulating layer in between. Such a junction has four possible resistance states, two from the relative FM polarization of the conductors and two from the FE polarization of the insulator. Multiferroics
have potential applications in computing because of these multiple resistances. The purpose of this project was to study the two resistance states of the insulator in a junction made of FM LaSrMnO3 (LSMO) and FE BaTiO3
(BTO).
This project required me to use a closed‐cycle helium cryostat to cool the samples to around 4 K, the temperature at which the measurements of the BTO layer were taken. In addition, my mentor and I used pulsed laser deposition and sputter deposition to fabricate the samples. Participation in this project has given me invaluable experience with various measurement and sample testing techniques, as well as the confidence to carry out experiments on my own. The research methods that I have learned can be applied to other areas of study, especially in solid state physics. Adsorption of Hydrophobic Anions into Polymer‐Intercalated Fluoromica: Understanding the Mechanism of Anion Exchange
Matthew A. Koc, Department of Chemistry, Westminster College, Salt Lake City
Camden N. Henderson and Thomas E. Mallouk , Department of Chemistry, Penn State University
Anionic contaminates such as perchlorate and
chromate are toxic at low concentrations and
may be contaminating drinking water sources.
The cationic polymer‐intercalated clays
synthesized in this lab have the potential to
detoxify water sources, however they are not
well understood on a fundamental level. These
studies will aid in the design of better
materials for adsorption and subsequent
release of environmentally hazardous anions.
I synthesized the anion‐exchanging clays with various amine polymers and investigated how
the structure and energetics of the polymer/clay composite affected the binding of
perchlorate. I characterized the composites with X‐ray powder diffraction, ion
chromatography, and solution calorimetry. This summer I learned several different
laboratory techniques and learned to operate the various instruments. Perhaps the most
important thing I learned was that I want to be involved in a similar type of research when I
go to graduate school.
REU Topics from Penn State Students
Characterizing Correlated Noise in IceCube
Nick Stanisha, Department of Physics, Penn State University
Jason Koskinen, Dr. Tyce DeYoung, Department of Physics, Penn State University
Currently, research at a 300-million-dollar
neutrino telescope known as IceCube is
being impeded by the presence of a
strange noise. This project is designed
to eliminate the noise as soon as
possible so that research of low-energy
neutrinos can continue.
Currently we are working on a suitable
simulation for this noise. This simulation
will help us confirm one of the
hypotheses we have that attempt to
explain the observed noise. The projects
I'm working on now will eventually be
used to eliminate this noise from all
future experiments.
Event Reconstruction in a Large Volume Atmospheric Neutrino Detector
Ryan Eagan, Dept. of Physics, Penn State University
Tyce DeYoung, Department of Physics, Penn State University
The IceCube South Pole Neutrino Observatory collaboration has begun R&D on a new upgrade for IceCube, named the Precision IceCube Next Generation Upgrade, or PINGU for short. PINGU will ideally extend the energy threshold of IceCube from 10 GeV down to a few GeV, providing greater resolution for neutrino oscillation studies.
To be able to perform neutrino physics with PINGU, the first step is to transform the raw signal data from the detector’s hardware back into an event described by physical quantities such as energy, position, speed, etc. This process is called event reconstruction. A very widely used method of event reconstruction throughout the experimental particle physics community is the maximum likelihood method, also the method used in our reconstruction software Hybrid‐reco.
The main focus for part one of my project will be to analyze Hybrid‐reco to find opportunities for improving overall performance and efficiency. Optimization of the quality of the
reconstructions performed by Hybrid‐reco will be achieved through exploring alternative numerical minimization and first guess algorithms.
The improved performance of Hybrid‐reco will in turn provide a means to compile a large sample of event reconstructions from the PINGU simulations. Varying the parameters of both the simulations and reconstructions provides valuable insight regarding the design of PINGU, including key factors such as geometric configuration of the optical sensors within the ice and necessary timing resolution of the optical sensor’s electronics.
The effect of time transformation on quantum evolution
He Jiang, Department of Physics, Penn State University
Prof. Martin BojowaldDepartment of Physics, Penn State University
Loop quantum gravity and cosmology are
crucial on the process of finding agreement of
quantum mechanics and quantum relativity.
There are two tasks in general: to read through
references on quantum gravity and cosmology,
and learn the significant methods mentioned
through those readings; and try to apply those
methods together with equations to harmonic
cosmology where time is not fixed and exists
no Hamiltonian, and thus be able to get some
new equations in the end.
This experience I have gained through this summer project will provide me a good example
about how theoretical physics work can be done in a researching environment. Moreover, it is a
great opportunity to learn significant things before applying a graduate program related to
quantum cosmology. In conclusion, this experience taught me a lot in advance and give me
guide to the future path.
Analysis of Field Inhomogeneity and Geometric
Distortion in 3T MRI
David Little, M. Wasil Wahi-Anwar and Dr. Susan K. Lemieux
Department of Physics, Penn State University; Department of Physics, Penn State University;
Social, Life & Engineering Sciences Imaging Center, Penn State University
One problem that affects MRI is geometrical image
distortion. The objective of our research was to
compare the accuracy and precision of three methods
of field inhomogeneity measurement: the Spectral
Peak method, the Delta Phi method and the Bandwidth
Difference method. Spectra and images were obtained
of a newly designed phantom modeled after the ACR
phantom. These measurements were applied to the
phantom data to determine how accurate they could
be if applied to human brain data.
This was my first time being able to truly work in
collaboration with other students in an actual research
“group”. It was a very eye opening experience as well
as a refreshing contrast from the stereotypical idea
that “scientists work in labs by themselves all day”. I
know I’ve taken a lot away from this program as a
whole and I can see now that doing scientific research
is indeed a team effort.
hBN/Graphene/hBN Dual Local Gates Structure Fabrication
DJ Seiwell
Jing Li, Jun Zhu, Department of Physics, Penn State University
Using a previously developed technique for the transfer of graphene to other substrates, hexagonal boron nitride (hBN)‐graphene stacks are being constructed to study the transport properties of such devices as p‐i‐n junctions. These devices will provide a window to the viability of using graphene transistors for the next generation of electronics. My role in completing the project was the fabrication of the devices. While the devices were not completed, many problems were overcome that will allow for the completion of them in the future.
t‐G
t‐hBN
b‐hBN
b‐G
quartz
G
N
D
D
C
The goal of this project is to acquire a deeper understanding of the electron‐electron interactions in bilayer graphene. It introduced me to many of the other projects that are being conducted allowing me a better grasp of what I would like to be doing in graduate school and beyond. I also helped expand my problem solving and critical thinking skills as well.
Superconducting Proximity Effect in Magnetically
Doped Topological Insulators
David A. Hopper, Thomas C. Flanagan, Duming Zhang, Professor Nitin Samarth
Department of Physics, Penn State University
Interfacing topological insulators and superconductors has been predicted to create Majorana fermions, quasiparticles that could be used to build a condensed matter quantum computer. Recent research on the superconducting proximity effect has been completed only on topological insulators such as Bi2Se3. We wanted to explore the phenomena in a slightly different material such as Mn doped Bi2Te3. Our goal was to systematically study a magnetically doped topological insulator through magneto‐
electric transport measurements.
I studied both a Mn doped and undoped Bi2Te3 sample by connecting Indium superconducting contacts to the thin films and then cooling the samples down in a He‐3 cryostat. From there I took Resistance vs Temperature measurements, I‐V curves and Resistance vs Magnetic field measurements. Our results did not show the proximity effect in the Mn doped sample, in fact the opposite was observed; an increase in resistance at the Tc .
This project has been a great opportunity for me because it gave me exposure to working as a graduate student in a university laboratory as well as solidify my interest in the field of Condensed Matter Physics.
Determining Time-Dependent Proportionality Constants for Data
Obtained by the Forward Meson Spectrometer
Daniel Marshall, Department of Physics, Pennsylvania State University
Prof. Steven F. Heppelmann, Department of Physics, Pennsylvania State University
My project involves the Relativistic Heavy Ion Collider at Brookhaven National Lab (BNL). Specifically, I am running computer programs on data collected by the Forward Meson Spectrometer (FMS). The FMS is composed of an array of cells that detect high‐energy photons. Ultimately, the electronics of each cell produces a certain numerical value for each photon it detects. There is a time‐dependent proportionality constant that relates the numerical value produced by the electronics and the energy of the detected photon. To help determine this time‐dependent proportionality constant, each cell receives a uniform pulse of light from an LED every second. I analyzed the resulting signals produced by the cells as a result of these LED flashes to determine the calibration coefficients.
Completing this project taught me how to use computers in a research environment. I learned how to interact with files and data by using terminals (with tcsh) on Linux based operating systems. I also became fluent in C++ and its applications in ROOT (a program developed by CERN and used by almost all particle physicists).
Determining Time-Dependent Proportionality Constants for Data
Obtained by the Forward Meson Spectrometer
Daniel Marshall, Department of Physics, Pennsylvania State University
Prof. Steven F. Heppelmann, Department of Physics, Pennsylvania State University
My project involves the Relativistic Heavy Ion Collider at Brookhaven National Lab (BNL). Specifically, I am running computer programs on data collected by the Forward Meson Spectrometer (FMS). The FMS is composed of an array of cells that detect high‐energy photons. Ultimately, the electronics of each cell produces a certain numerical value for each photon it detects. There is a time‐dependent proportionality constant that relates the numerical value produced by the electronics and the energy of the detected photon. To help determine this time‐dependent proportionality constant, each cell receives a uniform pulse of light from an LED every second. I analyzed the resulting signals produced by the cells as a result of these LED flashes to determine the calibration coefficients.
Completing this project taught me how to use computers in a research environment. I learned how to interact with files and data by using terminals (with tcsh) on Linux based operating systems. I also became fluent in C++ and its applications in ROOT (a program developed by CERN and used by almost all particle physicists).
One Dimensional Behavior of Superfluid
Helium
Samhita Banavar, Department of Physics, Penn State University
Dr. Duk Young Kim, Prof. Moses Chan, Department of Physics, Penn State University
The experiment studies the behavior of helium
flow in a pseudo 1-d geometry. Theorists believe
that in a strictly one-dimensional system, there
ought to be no superfluidity. The flow of liquid
helium through a glass fiber at temperatures
below 4 K is measured with a quartz crystal
microbalance and a mass spectrometer. The
experiment probes the fundamentals of physics.
I had the opportunity of seeing this project
develop from the beginning. I therefore learned
how to design an experiment and critically think
about how to reach a goal. I built cells to house
the fiber and microbalance and installed it on the
cryostat. I then helped run the experiment and
analyze the data. The experiment is especially
exciting because it is novel and builds on but
goes beyond material from class.
Nitrogen‐Doped Carbon Nanotubes and their Application in Liquid Fuel
Aaron Long, Néstor Perea‐López, Ana Laura Elías, Florentino López‐Urías and Mauricio Terrones
Department of Physics, Penn State University
Multi-walled carbon nanotubes (MWNTs)
possess
outstanding
physico-chemical
properties with a wide range of potential
applications in various technological areas.
This research project sought to explore the use
of Nitrogen-doped MWNTs as catalysts in
liquid fuel generation.
This summer, I
synthesized and characterized CNx MWNTs.
Furthermore, I performed calculations related
to the electrical properties of nanotubes in the
theoretical framework of density functional
Prof. H. Terrones, Aaron Long, Prof. F. López‐Urías
theory.
I used aerosol-assisted chemical vapor deposition to synthesize the nanotubes.
Characterization techniques included scanning electron microscopy, Raman
spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Theoretical
work was performed in a Mac OSX environment with Quantum ESPRESSO. Any
future research I do will be greatly aided by my familiarity with these experimental
techniques. Additionally, the introduction to ab initio theoretical calculations will be
particularly helpful, as I had no prior experience with these kinds of calculations and
they were something I really enjoyed doing.
Loop Quantum Gravity and Cosmology:
Dynamical Exploration
Zhiyan Wang, Department of Physics, Penn State University
Martin Bojowald, Department of Physics, Penn State University
In the case of harmonic cosmology of discrete dynamics, the simulation of harmonic oscillator could be applied from quantum mechanics to cosmology. I am trying to find the corresponding features of harmonic oscillator in cosmology as much as possible, and solve for the wave functions of coherent states in cosmology. I simulate the traditional methods used in quantum mechanics to find the characteristics of harmonic oscillators, applying them to the case of cosmology and solve differential equations with minimum uncertainty for the wave functions. Through my summer project, I studied loop quantum gravity and cosmology, one of the most potential candidates for the unified theory, and worked with Professor Marin Bojowald to understand his work on loop quantum cosmology. Simulation of the CREAM Boronated Scintillator Detector using GEANT4
Suk Yee Yong
Tyler Anderson, Matthew Geske, and Dr. Stéphane Coutu
Department of Physics, Penn State University
The Cosmic Ray Energetics and Mass
(CREAM) project provides key information in
understanding cosmic ray acceleration and
propagation. In order to study the cosmic-ray
electrons via their neutron signals in CREAM’s
calorimeter, the properties of a new instrument
that will be used in CREAM, the boronated
scintillator detector (BSD) are analyzed.
Using a toolkit called GEANT4, I built a simulation of the
current BSD prototype calibrated with Californium-252 neutron
source. The results obtained were compared to understand the
effect of the BSD enclosure on calibration signal. This project
has enabled me to acquire new experiences working as a
computational researcher and thus stimulates my interest in this
field.
Cosmic Ray Air Shower Detection
Ryan Chesakis, Department of Physics, Penn State University
Dr. Paul Sommers, Department of Physics, Penn State University
Cosmic rays are extremely high‐energy particles from space. When they interact with the atmosphere, they produce an air shower cascade of more particles. One goal of
this project was to find a cost‐effective way of producing air shower detectors, allowing the creation of large arrays to gather data and help us better understand cosmic rays.
The two main types of detectors we used are scintillator
paddles and water Cherenkov detectors. I constructed additional scintillator
paddles and tested photomultiplier tubes used to detect the light produced when a charged particle passes through the scintillator. This summer project has given me valuable experience as a researcher.