Experiments Offered in

PY 452

Advanced Physics Laboratory

 

High Temperature Superconductivity (Haase)

            The experiment uses a commercial ceramic superconducting pellet that has silver electrodes in a 4-point configuration.  This sample will be cooled and electrical measurements used to measure the superconducting transition temperature.

Nuclear Magnetic Resonance (Golub)

            A measurement of the time constants related to the motion of the nuclear magnetic moments of hydrogen in a magnetic field.  The experiment involves the use of magnetic fields and computer-aided data acquisition.  The technique is used in condensed matter physics, chemistry, biophysics, and is the basis of Magnetic Resonance Imaging in medicine.

Muon Lifetime (Rowe)

            A determination of the mean lifetime of cosmic ray muons.  The muons are stopped in a plastic scintillator viewed by a photomultiplier tube and subsequently decay via the weak interaction.  The time difference between the scintillation associated with the stopping and the scintillation associated with the decay is measured via electronics and a fast oscilloscope.  You can also measure the Poisson distribution, describing the (random) times of arrival of the muons.

Acoustical Resonances of Closed and Open Tubes (Stiles)

            Resonances of various tubes will be measured by moving a microphone along its length.  The spatial variations of the resonance are measured as a function of tube type. 

Speed of Sound and Box Resonances (Stiles)

            Resonance frequencies of sound in a box will be measured with the aid of computer data acquisition as a function of the length of the box.  Mode types will be identified, and fitting will yield an accurate measure f the speed of sound.

Atmospheric Optics and the Sun (Hallen)

            The optical spectra of sunlight at the Earth's surface will be measured with a single grating spectrometer, photomultiplier tube, and computer aided data acquisition.  The Sun's black body radiation will be analyzed as will the spectral features due to the passage of the light through the sun and atmosphere.

Reflection from a Metallic Film (Aspnes)

            Thin films fabricated in a vacuum coating apparatus and ellipsometry are used to measure the complex index of refraction as a function of wavelength.  A tungsten lamp, monochrometer, and a rotating analyzer ellipsometer are used.

Surface Plasmons (Hallen)

            A very thin film of Aluminum is evaporated onto a glass prism in a vacuum coating apparatus.  Polarization/incident angle sensitive methods will be used to measure the absorption due to this oscillation of the surface electrons in the metal.

Doppler Free Saturated Absorption Spectroscopy (Young)

            Diode lasers (780 nm and 795 nm) will be used to carry out laser spectroscopy of Rubidium atoms.  Doppler broadened optical absorption lines will be obtained and the technique of saturated absorption spectroscopy will be used to study and perform various measurements on lines with resolution beyond the Doppler limit.

Scanning Tunneling Microscopy (Riehn)

            Various surfaces will be imaged with atomic resolution.  Graphite (HOPG) will be cleaved and imaged.  A gold film will be deposited onto a substrate in a vacuum coating apparatus.  Surface modification with the STM may be undertaken. 

Brownian Motion (Riehn)

            The motion of single microspheres is tracked using a fluorescence microscope. Particle trajectories will be analyzed, and the size of the spheres will be determined from statistical measures of the particle trajectories. It may be possible to investigate the motion of bacteria, and determine whether bacteria diffuse or move in “smart” ways.

Electronics (various)

            The theoretical calculations of the electronics exercises are measured, as are other common circuits.