Physics 457W: Experimental Physics
Fall Semester, 2014
Section 1
M. and W., 2:30 - 5:30 pm, 309 and 310 Osmond
Instructor
Ying Liu
152F Davey Lab
863-0090.
liu@phys.psu.edu
Office Hours: By appointment
Teaching assistant
Shaun Mills
3G Osmond
sim5291@psu.edu
863-0113
Office Hours: By appointment
Important Notice
Because radioactive substance is present in 310 Osmond, University regulations do NOT allow
food or drinks in this room. A failure of observing this rule will automatically result in an “F”
grade for this course.
• Textbook
No textbook is assigned for this course. However, a short introduction to each
experiment, along with documentation of the instrument to be used, can be found at
http://sites.psu.edu/physics457/
Students are encouraged to also use resources available in the library.
• The course
This course is to provide an introduction to experimental techniques used in modern
physics research labs and learn how to conduct physics research. It is designed to train
students to work independently and creatively, and learn how to write scientific papers.
The students should try to work on their own as much as possible. However, the
instructor and the teaching assistant will be available to help when needed. Only a few
lectures will be given in this class for the entire semester.
• Organization
Two students will do experiments in a team. Number of experiments: 2-credit students: 4
short experiments only. 3-credit students: 3 short and 1 long experiments.
For short experiments, each team is required to choose one experiment from each of the
three categories (see below). The 2-credit students can do the last short experiment from
any category after doing one experiment in each of the three categories.
• Lab reports
The lab report is a very important part of this course with or without the additional
writing requirement. You need to set significant amount of time aside for writing reports.
While the two students in a team will share the data, each student will write his/her own
lab report. For format and writing style, please see instruction below.
To fulfill the writing requirement for Phys. 457W, your lab reports for short experiments
will be read by the instructor and returned to you with suggestions for revision. You will
make changes and turn the report in again, usually a week after you get it back.
Sometimes the report will be returned to you one more time for additional revisions. You
will again turn the revised report a week after you get it back.
No revision process will be carried out for the 2-credit students.
For the long experiment, there will be no revisions. However, you’re required to turn in a
preliminary lab report on the date as indicated below. The preliminary lab report should
include the introduction and the theory sections, and the results you will have at the time
(you should get most of the data already by then). I will make my regular comments and
suggestions. The purpose of this exercise is give the instructor a chance to see if
everything is on track and the students to get feedback.
All lab reports except your last lab report should be in the form of hard copies when you
turn them in. Please print it single-sided when it is possible. For your last lab report, you
should send in by email (in pdf and as an attachment).
• Lab notebook
It is very important for you to keep good record on your research work. How much notes
are needed is judged by a simple criterion: One of your classmates needs to be able to
repeat what you have done SOLELY based on your notes.
You need to purchase a good notebook – those with permanent binding and pages
numbered. You should be able to purchase one in the University Bookstore. You’re not
supposed to tear off any pages. If you make a mistake, or simply don’t like what you’ve
written, just cross it out and start over again - Every page of the logbook stays in the
book.
More specifically, you need to enter the following information: a) Title of the project, the
starting date, your name and your partner’s name (and your partner’s contact
information); b) List of goals; c) List of daily tasks; and d) Other useful information.
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Your notebook will be graded by your TA at appropriate times for grading.
• Oral exam:
There will be a session for oral examination towards the end of the semester. The oral
exam will cover mostly the short experiments while the long experimental may also be
included. Each student will have a 10-min. session with the instructor to assess the
individual understanding of the course material. This is designed mainly to supplement
the evaluation on your work in the course that is done mostly with your lab partner.
• Grading:
25% for notebook (5% each short experiment, 10% for the long experiment), 50% reports
(10% for each short experiment and 20% for the long experiment), 15% for the oral
exam, and 10% for overall performance.
Points will be taken off for late lab reports/notebook.
• Factors taken into considerations for grading the experiment and the report parts:
Experiment:
1) Motivation and persistence.
2) Completeness of the measurements.
3) Correctness of the results.
4) Understanding of the physics including the possible sources of error.
Report:
1) Correctness in physical concept.
2) Compliance to the format of the report as described below.
3) Clarity and style.
4) Completeness, including error analysis.
Overall performance will be evaluated based on your quality of work, initiatives, and
participation.
There will be no written exams for this class.
• Error analysis
The experimental error is the deviation of your measurement from the true value of the
quantity, a number that can be estimated in a scientific way. It is NOT the same as the
difference between your measurement and the accepted value of what you are trying to
measure (which, unfortunately, is commonly assumed), even though the accepted value is
presumably close to the true value. For the purpose of this course, this distinction means
that we usually do NOT obtain the experimental error by simply comparing the result of
our measurements with the accepted value.
More detailed discussion on error analysis is posted on the course website.
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The error analysis is very important for scientific research as it helps us understand nature
of the measurement, and ultimately, how much you can trust your results. To track down
all sources of error and come up ways to eliminate them when possible is an intellectually
challenging task.
Your final result for quantity X should be written as (X ± X) followed by the unit of the
quantity, where X is the estimated error of X.
Instruction for writing lab report (Very Important!)
1. The lab report should include the following sections:
• Title page. Include the title of the experiment, your name and your lab partner’s name,
and the date on which the report is turned in, and for 457W students, which version (first
or second) of the report it is.
• Abstract. Summarize the purpose, method, and the main results of the experiment.
• Introduction. What? Why? How? A short discussion on the history of the experiment
is fine. But it should NOT be the main part of the introduction.
• Theoretical and other background information.
• Experimental method(s). A schematic of experimental setup is required.
• Experimental results. Include raw data in an appropriate form, analysis of the data.
• Evaluation of experimental uncertainties.
• Discussion and conclusion. Indicate the main implications of the experimental results.
• References. Cite the most relevant ones. Elementary things from common textbooks are
not necessary to reference. Follow American Physical Society (APS) style when citing a
reference.
2. The lab report should be around 6-7 pages for short experiments and around 10-15
pages for the long one, excluding illustrating figures and plots of experimental results.
3. Use 12-point fonts and 1.5-line spacing for your reports.
4. Each figure should include a figure caption, placed below the figure. If you use tables,
each table should have a table caption, placed above the table.
5. Writing styles should follow American Physical Society (APS) style handbook,
available online at http://publish.aps.org/STYLE/
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6. The ultimate goal of this exercise is to gain the ability to write research papers of
publishable quality.
7. Turn in all lab reports in the form of single-column, single–sided hard copy.
Class Calendar
Week
Dates
Activities
1
8/25
8/27
Introduction: Pick and start with the 1st short experiment
1st short experiment
2
9/1
9/3
Labor Day, no classes
1st short experiment; lecture on error analysis.
3
9/8
9/10
1st short experiment; lecture on writing lab notebook
1st short experiment, pick the 2nd experiment
4
9/15
9/17
Finish 1st experiment report. Class will not meet,
2nd experiment; report for 1st experiment due
5
9/22
9/24
2nd short experiment
2nd short experiment;
6
9/29
10/1
2nd short experiment, pick the 3rd experiment
Lecture on lab report writing
3rd short experiment; report for 2nd experiment due
7
10/6
10/8
3rd short experiment
3rd short experiment; pick the long experiment
8
10/13
10/15
3rd short experiment;
Long experiment; Report for 3rd experiment due
9
10/20
10/22
Long experiment
Long experiment
10
10/27
10/29
Long experiment
Long experiment
11
11/3
11/5
Long experiment
Long experiment
12
11/10
Long experiment
Preliminary lab report due
Long experiment
11/12
5
13
11/17
11/19
Finish the long experiment.
Work on lab report. Class will not meet.
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11/24 & 11/26
Thanksgiving week. No classes.
15
12/1 & 12/3
Oral exam.
16
12/8 & 12/10
Finish lab report for the long exp. The class will not meet.
Final lab report due on Friday, 12/12.
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12/15 – 19
Finals week. Class will not meet.
List of experiments
Short experiments (in three categories)
I. Fundamental constants
1. Speed of light (rotating mirror method)
2. Cavendish experiment (gravitational constant measurement)
3. Current balance (Ampere’s law)
4. Oil droplets (charge quantization)
II. Waves and resonance
5. X-ray diffraction
6. Driven harmonic oscillators
7. Electron spin resonance (ESR) (short)
8. Microwaves (“geometrical optics” of microwaves)
III. Others
9. Chaos
10. Franck-Hertz experiment (resonant scattering of electrons by Hg atom)
11. High Tc superconductors (levitation, critical temperature and current)
12. Brownian motion
Long experiments
1. NMR experiment
2. Optical experiments (absorption, blackbody radiation, photoluminescence)
3. Long ESR experiment (electron spin resonance spectroscopy).
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4. Hall effect, determine the properties of the charge carriers and the band gap in
semiconductors.
5. Laser experiment, Doppler free spectroscopy
6. Muon decay, determine the life time and the speed of muons in the cosmic rays.
7. Compton scattering and gamma ray absorption (scattering of photons by free electrons
in metal)
8. Mossbauer effect, measure changes in the nuclear spectrum of 57Fe to determine its
local environment.
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