Graduate Physics Laboratory Faculty Handout
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Faculty Handout for Fall 2005

1. Introduction


The purpose of the Graduate Laboratory is to give students an in-depth experience in experimental physics where they can see how laboratory measurements are used to test ideas in physics. Students should learn how to make meaningful comparisons between their data and a theoretical model. They will have an opportunity to use and understand some contemporary measurement techniques. Each student will be required to complete two experiments from two different areas of physics and to produce a report in the form of a journal publication manuscript for each. These two experiments are the main focus of the course. However, the other aspects of the course will contribute significantly to the grade.

The following grade breakdown is more structured than has been traditional. The intent is to make expectations more explicit so that time and effort may be better managed. The percentage distribution is as follows:

1. Lectures and attendance on Scheduled Lab days (10%)
2. Experiment Documentation (10%)
3. Experiment Demo and Tour (10%)
4. 1st Experiment 30%)
1. Proposal (5%)
2. In lab-work and lab-notebook (10%)
3. Paper (10%)
5. 2nd Experiment (40%)
1. Proposal (5%)
2. In lab-work and lab-notebook (10%)
3. Paper (20%)




2. Lectures and Attendance


Attendance for the first hour of the class scheduled time, and for at least three hours of the scheduled lab session, is mandatory (and will account for 10% of your grade). If you don't believe you can make class regularly at that time see the instructor now. Attendance will be more strongly emphasized than in past years. The lectures will cover practical aspects of dealing with Grad Lab: using equipment, performing experiments, doing statistical analysis, writing papers, and doing the lab work-sheets. Attending class consistently will make the course easier. Most importantly, this will be a regularly scheduled time when we can find out how we can help you with your experiment. Regular contact between us is essential.
 
3. Documentation of Experiment


You should expect to find a copy of all cited articles (expect possibly from books) as pdf files linked from the web bibliography. This is a new mounting of the articles. If you find bad links please mention this to the TA or the instructor.  We would like to improve the files. One way is for students to contribute some documentation for each experiment that they perform to the files. The instructor and student should decide which items are appropriate for each experiment file during the defenses.
 
4. Experiments


All students will do two experiments. Some experiments are very challenging while others are more straightforward. Typically, the first experiment is the most difficult because you will not be familiar with Grad Lab and how it works, where things are, and what, exactly, you should be doing. Going through the complete cycle of the first experiment will prepare you so that you can be more ambitious on your second experiment.

There are eight parts to each experiment:


1. Experiment Discussion
with the instructor

This is a 20 minute exploratory discussion of the experiment you have chosen. Its purpose is to identify an appropriate measurement goal and it will be a chance for you to ask questions and advice on how to get started. Reading the papers referenced in the manual will help familiarize you with your options. The better prepared you are the more you will get out of this discussion, but we understand that it can be a challenge figuring out what's going on at first. This discussion is for your benefit. It is mandatory, but not graded.
 

2. Oral Proposal

Supported by your lab notebook, you will present a short discussion of the experiment you plan to do; what the physics behind the experiment is, how and with what equipment you will perform the experiment, and what the statistical design of the experiment is. You should be able to predict (though you might not be right) the accuracy and precision of your expected results. You should already have begun to familiarize yourself with the setup of your experiment before the proposal so that we can discuss the experiment in as much detail as possible. But, do not use equipment until you are confident that you know how to use it correctly. Starting an experiment can be the most difficult part of this course so don't be afraid to ask questions and for help! The proposals will be graded.
 

3. Performing the Experiment

Taking data is generally the easiest and fastest part of Grad Lab experiments. Most of your time will be spent in familiarizing yourself with your experiment, setting up your apparatus, and testing (and calibrating!) equipment. To receive credit for doing the experiment, you must demonstrate and explain the working experiment to the instructor. It is your responsibility to arrange with the instructor a time to do this.

You are required to keep a bound page-numbered research notebook in which all your work on your experiments is described in ink! The notebook should be a "Computation Book" with large 9 1/2" x 11 5/8" numbered quadrille pages or equivalent. DO NOT BUY THE SIMILAR LOOKING LAB NOTEBOOK WITH WHITE AND YELLOW PAIRED PAGES WHICH TEAR OUT EASILY. IT IS FOR LAB NOTE SHARING AND IS NOT SUITABLE FOR THIS COURSE. Keep this notebook as a research journal, in chronological order with each entry dated. Include a summary of your reading and study on experimental background; experiment design; preliminary calculations and error studies (What will be the most significant errors?); description and characteristics of the instruments used and their calibration; analysis of the procedure and first data taking to check feasibility; detailed recording of the final data with enough detail of gains, equipment, etc., to allow you to return to where you left off in a minimum of time.

This notebook is the detailed record of your experiment. Learning to keep a research journal is an important skill as a scientist and essential to doing a good experiment. Do not neglect it. It will be graded.

Because students may be sharing equipment you need to be both considerate and assertive. If you leave equipment running that may need to be shared, leave a dated note with your name, email address, and phone number.

The purpose of doing an experiment is to obtain the best results possible, subject to the constraints of time and equipment. You should maximize your effort toward these goals. In particular, it makes little sense to devote a great deal of time and effort to measure a value to 1 part in 10⁴, if you know the calibration is no better that 1%.
 

4. Mid-Experiment Progress Report

There will be weekly progress reports as well as the mid-experiment progress reports scheduled on the calendar. They will count as part of your in-lab work grade. These are meant to help you. Students sometimes try to do too much, focus on the wrong aspects of experiments, or stop making efficient progress, and don't realize that we can help if we know what their situation is. The quality of these reports is not graded. You get full credit for simply having a meeting with the instructor. The nature of the report depends on the experiment, but will, at least, consist of a review of your notebook!
 

5. Experiment Demo

You will demonstrate a working experiment to the professor and/or the TA at a mutually agreed upon time. The discussion should be quantitative and detailed. Demonstrations will consist of:

1. showing how various components of the instrumentation work and how data are collected;
2. justifying the specific choice of instrumentation;
3. explaining the data and the analysis.

These demos can take anywhere from 10 min. to an hour depending on the experiment and your preparation. For experiments requiring special preparation, such as liquid He, arrangements must be made in advance. It is best to show real signals from the experiment.
 

6. Experiment Tour

Near the end of each experiment, you will give a qualitative explanation of your experiment to your classmates. The entire group will do this together by going from station to station. We will select one of the lab days for this event. Note: Class conflicts will require that you miss your other, conflicting class, dependent on the time needed. You should prepare to talk for between 10 and 15 minutes. If it is possible to show live signals from your experiment, please do so. But, the purpose of this exercise is to give you the chance to explain what you are doing and for others to benefit from your new-found knowledge. The tour need not be as comprehensive as the demo for the instructor.
 

7. Rough Draft and Defense

The "rough draft" is a chance for us to give you feedback on what your final paper should be like before you spend inordinate amounts of time writing it. You should have your Figures, Captions, and Tables for the paper ready for this draft presentation. An outline of the paper would also be helpful. You don't need to have all of the writing done, but useful comments could be made about the procedure and discussion sections of the paper, if they were ready. This should help you spend your time more effectively. The rough draft is not graded, but it is essential if your final paper is going to meet my expectations. The defense is just the process of supporting your draft with you notebook as support for your calculations, uncertainties in results, and figures.
 

8. Written Paper

The final paper should include a summary of the relevant theory, description of how the experiment was performed, data and analysis, in-depth discussion of errors, results, and conclusions. The length of the theory section should be limited to a few pages at most. The paper should be typed in the manuscript style of an article for a journal of The American Institute of Physics. It must contain appropriately footnoted references. (See the Graduate Laboratory Handbook for further details on format). The tone of the paper should be that of an experimental physicist performing a "real" experiment. The emphasis is on the quality and validity of the work, not on getting the right result. Disagreements with simple theory or other results should be discussed in light of experimental technique and uncertainty, as well as potential higher order theories. Often the small, but statistically significant, bump is the most interesting part of the experiment.

Presenting your results with a clear description of a valid error analysis and major errors is essential. It is also essential that your notebook contain the original data and analyses supporting your: results, uncertainties, tables, and figures of the draft and written papers. Work done in spread sheets, plotting, and fitting programs needs to be documented with file names, descriptions of calculations, and conclusions. Plots or at least reference to hard copies of plots in folders are also useful.

5. Other Relevant Information
   
1. Organization and  Required Books

The facilities, regulations, and organization of the Graduate Laboratory will be described by Mr. Monroe and the instructor. The data analysis book, Data Reduction and Error Analysis for the Physical Sciences (Second Edition) by P. R. Bevington and D. K. Robinson is a required book for the course. (A useful reference for a more elementary treatment of error analysis is An Introduction to Error Analysis by J. R. Taylor.) The Bevington text includes the Turbo Pascal algorithms used in the Graduate Laboratory data analysis programs LINREG and ANALYSIS. The second required book is the American Institute for Physics Style Manual. The Style Manual is now available on the web at http://www.aip.org/pubservs/style.html .   This manual give a full description of the format details of preparing manuscripts for publication  and will be the style that you will use for your reports in the Graduate Laboratory.



2. Computers

Data analysis and plotting must be done on the PC's in the laboratory. Approval must be obtained to use other computers for these tasks because outside programs often do not do the required statistical analysis. The Graduate Laboratory has a selection of analysis and plotting programs available. We will be glad to give you any help you need learning to use these programs. See the appendix of the Grad Lab Manual about our software.
 

3. Communication
with the instructor

Regular communication is essential in Grad Lab. Besides the required attendance on your scheduled lab day, E-mail is the next easiest way to send messages. You are expected to check your e-mail regularly, at least daily.

To facilitate communications please list your office, office-phone, e-mail address, and home phone numbers on the information cards that will be circulated to the class members. Let me know of corrections needed to this information on the copy once it appears on the bulletin board. Note that the "Student Roster" form on the web pages provides phone and email information for students who may be sharing equipment.
 

6. List of Experiments


Listed below are the available experiments.

We may require you to defer your selected experiment to permit orderly scheduling; there is only one copy of each experiment. In general, it is preferred for only one student to perform any experiment from each lab section. Exceptions for which two students may be permitted to sign-up are denoted with a "(2)". The experiments must be done independently, even if sharing the equipment.  Scheduling must be arranged so that each student working on a two-student, shared experiment has time on the apparatus during the scheduled hours of the class for the purpose of discussions with the faculty and TA.

Numbering of the experiments is in accord with the Graduate Laboratory Handbook.

Diversification is required — you may not do all your experiments in low-temperature physics, for example. 

2.1.3   Mössbauer Effect (2) - out for replacement of electronics

2.1.7  Critical Phenomena: Ferroelectric Crystals (2)

2.1.9  Acousto-optic Diffraction (2) - needs upgrade of position readout

2.2.1  Second Sound in Liquid Helium II (2)

2.2.2  Superconductivity (2)

2.3.1  Compton Effect

2.3.3  Angular Correlations -- weak source

2.3.4  Rutherford Scattering

2.4.1  Lifetime of the Cosmic Ray Muon

2.7.1  Thermal Noise

2.7.2  1/f Noise

2.12.3  Critical Phenomena: Critical Opalescence (2)

For queries regarding:

Content, contact the Laboratory Coordinator.

Technical Questions, contact the Laboratory Coordinator.

Last update 09/12/05 12:17 AM