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The experimental physics program at URI covers areas of
biological physics, optics and spectroscopy, nanotechnology,
cold neutron physics, low temperature atomic clusters,
structure of surfaces and interfaces, growth of epitaxial
films, magnetic nanoparticles and surfaces, x-ray diffraction,
neutron diffraction, and photoemission spectroscopy.
We believe that a core component in the graduate education
in experimental physics is to provide students with a
supportive environment in which they, after initial training,
are able to find their own initiatives in pursuit of research
interests, and eventually become the primary experts in their
respective fields. Most of the experiments in our research are
performed in laboratories on campus, where each research
student takes the responsibility for a project and apparatus
under the guidance of a member of the physics faculty. Some of
the experiments are performed at other national and
international user facilities through multi-institutional
collaboration. These collaborations are of small scale
involving two or three groups, and students participating in
these experiments also acquire first hand expertise, much the
same way as in campus laboratories.
Many of the physics faculty are also members of the Sensors & Surface Technology
Partnership, which is an interdisciplinary materials
research consortium at the university, in partnership with
departments of electrical engineering, chemical engineering,
mechanical engineering, food science and nutrition, and
chemistry, as well as with local and national industrial
sponsors.
 Prof.
David Heskett works in experimental condensed matter
physics, specializing in the physics of surfaces and thin
films. He conducts experimental investigations of the
electronic, structural, and dynamic properties of clean and
adsorbate-covered metal and semiconductor surfaces and thin
films using a variety of surface probes. Experimental
techniques include X-ray Standing Waves (XSW), Angle-Resolved
Ultraviolet Photoemission Spectroscopy (ARUPS), Inverse
Photoemission Spectroscopy (IPES), High Resolution Core Level
Spectroscopy (HRCLS), Auger Electron Spectroscopy (AES), Low
Energy Electron Diffraction (LEED), Atomic Force Microscopy
(AFM), and Rutherford BackScattering Spectrometry (RBS). Prof.
Heskett is also interested in electromigration in aluminum
alloy interconnects.
Prof. Jan Northby works
in experimental low-temperature physics, studying beams of
superfluid helium nanodroplets. The primary motivation is to
learn about the effect of finite size on superfluidity. In
order to study such a weakly interacting system it is necessary
to create or attach a probe particle of some sort. His research
program has centered on those particles created in clusters by
electron bombardment. Most recently, the group has been
studying the spectroscopy of metastable helium molecules
attached to the surface of helium nanodroplets. The study
exploits a new kind of laser spectroscopy in which absorption
of a photon leads to the detachment of a metastable particle
from the surface. In addition to studying the spectral
modifications induced by the particle-surface interaction, the
high detectability of such particles permits measurements of
their recoil momentum. This in turn provides additional insight
into their dynamical interaction with the nanodroplet.
Other experimental projects underway in Prof. Northby's
laboratory include the development of beam sources of
metastable helium molecules, and the development of a laser
based sediment velocimeter that can be used to study sediment
concentration and motion in natural waters. ( Sketch of Helium Cluster Beam Apparatus
).
Prof. Tony Nunes works in
experimental condensed matter physics and neutron physics,
specializing in the fields of neutron scattering and x-ray
scattering. Prof. Nunes is a former student of Prof.
Clifford G. Shull of MIT who was awarded the 1994 Nobel
Prize in physics for his pioneering development of neutron
diffraction physics. Neutron diffraction provides an
indispensible probe of condensed matter. Prof. Nunes studies
magnetism in nanoparticles and surfaces. Particles (a few
nanometers in diameter) of some ferrites seem to have a
magnetically anomalous surface layer about a nanometer thick.
This layer also appears to be characterized by significant
relaxation (expansion) arising from the different termination
properties of the long range coulombic attractions and the
short range repulsion between ions. This and the
magnetoelasticity of the lattice may, at least in part, account
for the magnetic anomaly.
 Prof.
Suren Malik and Prof. Albert
Steyerl work in experimental neutron physics with main
interests in ultra-cold neutrons (UCN) and neutron optics. They
are collaborating with physicists at Kyushu University (Japan),
the Institut Laue-Langevin, Grenoble (France), and Harvard
University in studies of the properties of ultracold neutrons.
These neutrons have energies of 10^-7 eV or less and are
totally reflected for any angle of incidence on a wall made of
a suitable material. Due to this property, the UCN can be
stored in special UCN traps for hundreds of seconds.
 Prof.
Steyerl's research is focused on the details of the
UCN-wall interaction and specifically on the question why the
measured storage losses always seem to exceed the theoretical
values. Very long storage lifetimes are required for
applications of UCN in precise measurements of the neutron
lifetime for beta-decay and in sensitive searches for an
electric dipole moment of the neutron. Both of these quantities
are of fundamental importance in theories of elementary
particles and of cosmology. Experiments are performed at the
UCN Source of the High-Flux Research Reactor of the Institut Laue-Langevin, Grenoble,
France.
Professors Yana
Reshetnyak and Oleg
Andreev carry out research projects in various fields of
experimental physics:
- Biological Physics
- thermodynamics and kinetics of folding of membrane
proteins
- molecular mechanism of muscle contraction
- protein fluorescence: novel mathematical algorithms
of spectra analysis and application of the
computational/statistical approaches for the correlation
of protein spectral and structural properties
- Medical physics/Nanotechnology:
- development of novel nanotechnology delivery platform
for the selective targeting of diseased tissue for
diagnostic and treatment
- whole-body imaging, gene therapy, hyperthermia of
cancer induced by illumination of carbon nanotubes
etc
- Nanotechnology and optics:
- fabrication of semiconductor nanowires using
biological molecules as a template, studies of their
optical and electrical properties
Detailed descriptions of these project can be found on the
web pages of professors Reshetnyak and Andreev.
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