The University of Akron
Department of Physics
COURSE: 3650:451/551 - ADVANCED LAB
INSTRUCTOR: PETER HENRIKSEN
OFFICE: RM. 3, AYER HALL
PHONE: 972-6054
The primary goals of Advanced Lab are to introduce
you to the instrumentation and techniques of experimental physics at an
advanced level and to provide experiences that will be helpful when seeking
employment. A major objective is for you to learn to apply the concepts
and principles of physics that you have learned in our lecture courses.
Other objectives are; (a) to plan and design an experimental investigation;
(b) to write a well organized report of your investigations; (c) to learn
strategies for solving practical problems, and (d) to develop skills in
instrumentation and computer interfacing. Additional techniques you will
learn during the year are: (a) the use a computer-controlled data acquisition
boards, (b) the fundamentals of vacuum technology, (c) how to use the following
computer software: Maple V, Mathcad, Microsoft Excel, Surfer, and Matlab.
During the first semester you will complete four
of the experiments from the list below. You will have four weeks to work
on each experiment, and a written report is due at the end of each four-week
period. There will be more experiments than four-week periods so that you
will have a choice of experimental projects on which to work. You will
be provided with basic introductory materials for each of the experiments,
however, you are expected to find additional literature related to the
fundamental theory and applications of the experiment. Library books and
journals are excellent resources for information related to the experiments.
An important aspect of each experimental project is the final week. During this week you will use the experimental technique of that particular project to analyze a sample or do an investigation of your own design. Of course you should start planning and thinking about this application of the experimental technique during the first week of the project; it’s important to get an early start, and you can always discuss a particular application with me or others who have done the experiment. It is important that I approve the application.
During the second semester you may continue to work on four-week experiments chosen from the list of available experiments, or you may work on small research projects that can extend beyond 4 weeks. If you choose to work on a project, then you are free to choose a topic in an area of interest to you, or I can suggest several topics from which you may select one as a project. In either case we will work together to design an experiment with emphasis on data collection, analysis, and an in-depth understanding of the physics involved. Frequently students choose to do extended work on one or more of the four-week projects.
Each project is designed to give you research experience
in a particular area of physics as well as acquaint you with ideas and
instrumentation. For example, you may wish to spend 4 weeks learning to
use the scanning tunneling and atomic force microscopes. During that period
you will learn in detail the physical principles underlying the operation
of each microscope and how these principles are use to generate an image
of the surface relief of chosen samples. You will calibrate each instrument
by imaging a gold diffraction grating with ruling of a know separation.
After obtaining an image, you will learn to use the various software packages
for data analysis and presentation. Also, you will image the (111) surface
of highly oriented pyrolytic graphite (HOPG) to obtain atomic resolution
and learn the basics crystallography. Finally, during the forth week you
will prepare a surface of your choice to image and analyze. This task will
require advanced planning and should commence during the second week of
the project. For this final task some questions you should consider are:
does the surface you wish to image have a known order or structure; if
the material is amorphous, what information can you gain from imaging the
surface; are there auxiliary techniques you can use to supplement your
analysis?
After choosing a project you will do a literature survey and develop
a research plan.
This example has been given to point out the elements
of each project and their importance. These elements include:
(a) theory,
(b) principles of
instrumentation,
(c) measurement of
known samples,
(d) calibration of
instrument,
(e) application
of technique to analyze a sample or solve a problem of your choice,
(f) summary of results,
(g) preparation of
written report.
A report on each project will be due by 5:00 p.m.
on the Friday at the end of each four-week period. Your report should contain
a section on each of the elements listed above and must be written using
MS Word, double spaced, and printed. Also, I would like software copy of
each report on a ” disk. Every effort will made to grade your reports
and return them the following week with suggestion or comments. If a few
cases you may be asked to rewrite your report. Your final grade will be
the average of the grades of each report. If a report is turned in late,
your grade will be reduced by one letter for each week it is late. Your
last report for the semester is due no later than 5:00 p.m. on Tuesday
of final exam week. Please give your lab report to me as opposed to placing
it in my mailbox, and return all printed materials at the time you turn
in your report. By that time all apparatus and tools you have used during
the semester should be in good operating condition and returned to their
place of storage. If there is a problem with any of the equipment, please
let me know so that it can be repaired during the time between semesters.
The completion of the student-initiated application will weigh heavily
in your grade for each project.
This course is equivalent to a lecture course in that you are expected to work more than the two scheduled two-hour periods. Please do not expect a grade better than "C-" if you only work four hours per week. You will not be given a grade until the area in which you work is organized, all tools and equipment returned to their proper place, and all books, manuals, or articles are returned.
Projects:
Below is a list of our current 4-week projects:
1. Optical spectroscopy - In this experiment
a monochromator is interfaced to a PC and one can obtain a spectrum in
the UV/visible spectral region. For example one can obtain the emission
spectrum from a mercury vapor lamp or other atomic light sources, the absorption
spectrum of a sunscreen or other materials, or the fluorescent spectrum
of a dye. The objectives are to become familiar with optical spectroscopy,
methods of photodetection, data presentation, and data analysis. The basic
requirements of this experiment is to obtain the tramsmittance spectrum
of filters, and obtain and analyze the emission spectrum of an unknown
source; the objective being to identify the source.
2. He-Ne Lasers - this experiment utilizes
lasers with adjustable resonant cavities. In this experiment you will learn
about spontaneous and stimulated emission of radiation, optical pumping,
laser bandwith, longitudinal and transverse modes of vibration, the Fabry-Perot
etalon, population inversion, resonator stability, and gaussian beams.
In particular you will (1) image, identify and analyze several transverse
modes of the laser, and (2) use a scanning Fabry-Perot interferometer to
measure the longitudinal modes of a laser. In addition, several other He-Nelasers,
diode lasers, and a dye laser are available for a variety of laser related
experiments.
3. Fourier Transform Infrared Spectroscopy
(FTIR) - Here you will learn the fundamentals of how an FTIR instrument
operates, how to obtain spectra from various samples, and how to interpret
these spectra in terms of the normal mode vibrations of molecules.
In general, this experiment should follow the experiment on optical spectroscopy.
In theory, there are common elements in these experiments, and a good understanding
of optical spectroscopy will help you understand infrared spectroscopy.
4. Scanning Tunneling Microscopy (SPTM) -
You will learn the fundamental principles of operation of the instrument
and then use it to image two samples: a gold grating and HOPG. Before imaging
you must learn to prepare a sharp tungsten tip that will be used as the
probe for scanning. (This is a chemical etching process that will produce
a tip that is so sharp that you cannot see the end of it with a common
laboratory microscope.) These tips can only be used once and must be prepared
just prior to imaging. In special cases, those who master the use of the
STM may proceed to learn to use the atomic force microscopy (AFM).
5. Chaotic pendulum - This project utilizes
the Daedalon pendulum designed by James Blackburn and described in the
textbook: Chaotic Dynamics by Baker and Gollub. The user’s guide is written
by Blackburn and describes 5 experiments. This project consists of reading
the above mentioned textbook, completing the 5 experiments, describing
the general requirements for a system to oscillate chaoticlly, and identifying
at least three physical systems that can oscillate chaotically. In addition
to the experiments, you should obtain a good data set for analysis. Software?“Chaotic
Data Analyzer” as well as Matlab? is available for data analysis. A good
project would be to determine the Lyapunov exponent for a data set. Also,
another chaotic pendulum is available as well as components for making
a chaotic circuit know as Chua’s circuit.
6. Pulsed Nuclear magnetic Resonance - This
apparatus can be use to measure: spin-lattice relaxation time T1, spin-spin
relaxation time T2, diffusion rates when samples are placed in a know field
gradient, to measure precession in a rotating frame of reference, to measure
effective fields, off-resonance signals, and free-induction decay. This
equipment is interfaced with a digital storage oscilloscope, and the data
can be downloaded for analysis using Matlab or Mathcad.
7. Superconducting Quantum Interference Device
(SQUID) – The manual for this equipment describes a series of experiments.
One of the more advanced experiments can be used as a project. Since the
SQUID can measure magnetic field quantization, it is extremely sensitive
to small changes in magnetic field strength. This apparatus could be used
in conjunction with a magnetic pendulum to obtain chaotic data.
8. Problem solving - This project will focus
on various strategies for solving problems. In general, the problems will
be stated in simple and straightforward manner, they will involve a physical
situation rather than a mathematical puzzle or paradox, a unique solution
can be deduced without complex mathematics, the problems are not easily
found in common textbooks but will probably require you to use texts or
references.
9. Experiments in fiber optics - with this
apparatus you will perform experiments in: fiber dimensional characteristics,
linear attenuation, propagation modes, injection losses, characteristics
of a LED, photodector characteristics, and transmission of information.
Addition experiments are:
10. Symbolic Math (Maple) -
11. Electronics and instrumentation - A series
of experiments using OpAmps and the textbook: The Art of Electronics by
Horowitz and Hill.
12. Laser modes and laser feedback -
13. Diode laser -
14. Dye laser -
15. Inelastic electron tunneling spectroscopy
(IETS) -
16. Thin film growth, characterization, and
onset of epitaxial growth -
17. Demonstrating science with soap films
-
18. Surface roughness and fractal dimensions
of surfaces -
There are items such as oscilloscopes and the vacuum
evaporator that must be shared. Please used them with care and report any
problems with the equipment immediately. Your corporation and help are
important for our program to operate smoothly. Proper use of tools and
equipment is mandatory. After you have used a tool or instrument,
please return to its proper place of storage, and in good operating condition,
so than it will be available for someone else to use.
Everyone working in and using Room 11 has a designated work area. Please do not take equipment from someone's work area without leaving a note stating who has taken the equipment, where the equipment can be found, and when it will be returned. In general, leave other people's equipment alone. Some equipment belongs to particular projects and is not to be shared. This is particularly true for the tools used with the vacuum evaporator. If you are uncertain about the use of equipment, please discuss it with me.
Finally, this course is equivalent to a lecture course in that you are expected to work more than the two scheduled two-hour periods. Please do not expect a grade better than "C-" if you only work four hours per week. You will not be given a grade until the area in which you work is organized, and all tools and equipment returned to their proper place.
Articles appearing in the American Journal of Physics and Physical Review use the format adopted by the American Institute of Physics. Please use this format for your reports and write them using Microsoft Word. Computers with this software are available in Rm. 11 as well as the Computer Lab (Rm. 114). Each report should have the following elements:
Project title
Abstract
(A brief summary of the experiment, the instruments and methods used,
and the results of all measurements with as assessment of uncertainty in
that measurement.)
Your Name
and
Local Address
I. INTRODUCTION - background information relevant
to experiment.
II. THEORY - theoretical outline of experiment.
III. EXPERIMENTAL DESIGN - Detailed work plan which may include
drawings, schematic diagrams, supplies needed, apparatus, and sample preparation.
A general description of how the experiment was performed.
IV. EXPERIMENTAL RESULTS - a presentation data, graphs, and uncertainty
in measurement.
V. DATA ANALYSIS - describe techniques for analyzing data.
VI. CONCLUSIONS - A succinct statement of the results of the
experiment and numerical values obtained where applicable. Also include
any constructive suggestions for improvements and further work.
VII. REFERENCES - See articles appearing the American Journal
of Physics for examples of references.