Syllabus for
Physics 330:
Advanced Laboratory
Spring Term, 2006
1:10 - 4:00 MWF, Youngchild 126
Instructors: Joan Marler and Matt Stoneking
Catalog Course Description:
Independent work on experiments selected from the following areas: optical, Mössbauer, alpha, beta, gamma ray, and X-ray spectroscopy; optical double resonance; magnetic resonance; vacuum techniques; solid-state physics; laser physics; nuclear physics.
Course Objectives:
To acquaint
students with the practice of experimental physics, the use of contemporary
instrumentation, the essence of several landmark experiments, and the basics of
machine tool operation. This course
should strengthen student skills in conducting experiments, making measurements,
documenting lab activities in a notebook, explaining experiments at an
elementary level, making formal presentations, and writing a scientific paper.
Required Text:
· Experiments in Modern Physics, by Adrian C. Mellissinos and Jim Napolitano, 2nd Edition (Academic Press, 2003). This text serves as an excellent introduction to many of the experiments in the Advanced Lab. Sections of this text will also be assigned as preparation for discussion.
Materials:
Students in this course learn experiments by reference to various sources including journal articles (especially review articles) and instruction manuals. In addition to the required text, the following books may be useful when beginning a new experiment:
· W. Preston and E. R. Dietz, The Art of Experimental Physics (one copy in the lab).
· R. Eisberg and R. Resnick, Quantum Physics of Atoms, Molecules, Solids, Nuclei and Particles (one or two copies in the lab).
· The McGraw-Hill Encyclopedia of Science and Technology (in the reference section of the library).
The following books will be of occasional use in this course. There are several copies of each in the lab and/or the CPL:
· AIP Style Manual
· D. M. Cook, Theory of Experiment.
· P. R. Bevington and D. K. Robinson, Data Reduction and Error Analysis for the Physical Sciences.
· J. H. Moore, C. C. Davis, and M. A. Coplan, Building Scientific Apparatus.
Three-ring
binders and other materials set out for each experiment must remain in
Youngchild 126 (Atomic & Nuclear Lab), 128 (
Precautions:
Exposure to radiation must be minimized. Before using a radioactive source, review the catalog of sources attached to this document for information about its dangers. Machine tools are dangerous; use them only when a supervisor is present. Lasers are also dangerous; heed the precautions reviewed in the laser safety video and contained in the Q&A on Eye Safety with Lasers attached to this document.
Grades:
This course requires initiative, perseverance, and about 20 hours/week of lab time. Assistance from the instructor should be sought mainly during afternoon lab hours (MWF). Food and drinks, etc. do not belong in the lab. Incompletes are rarely given in this course. Final grades will be based on the following weighted components:
1) Notebook 30 %
2) Paper 25 %
3) Oral Presentation 15 %
4) Dialogues 15 %
5) Presentation of a PRL Article 5%
6) Participation (and leading of) discussions 5%
7) Colloquium Attendance 5%
Experiments, Paper and
Oral Presentation:
·
Each student is required to perform four
experiments.
·
One experiment (preferably the first) must be
done comprehensively, with the results being reported in a paper whose style resembles that of a 5-7 page physics publication
(see the AIP Style Manual). This
experiment, to which the student is to devote three to four weeks, should
include a novel extension (novel to
·
A second experiment, to which the student is to
devote two or three weeks, should also be performed comprehensively (but need
not involve a novel extension). The
student will present a formal, oral
presentation on this experiment, patterned after talks delivered at national
physics meetings. The length of the talk
is strictly limited to twenty-five minutes, followed by five to ten minutes of
questions from the class and instructor.
The presenter should use overhead transparencies or PowerPoint. She or he should explain the crux of the
experiment, present data, and summarize the results.
·
Two additional experiments, performed less
ambitiously (one to two weeks each), are intended to broaden student exposure
to important modern physics topics and instrumentation, and may be undertaken
in collaboration with a classmate.
·
The four experiments performed by the student
must include at least one magnetic or optical resonance experiment (group I
below) and at least one nuclear physics experiment (group II below).
I. Magnetic or Optical
Resonance
1. Magnetic resonance in optically pumped rubidium
2. Electron paramagnetic resonance at microwave frequencies
3. Quantum beats via time-resolved laser spectroscopy
4. Saturated absorption laser spectroscopy
5. Optogalvanic laser spectroscopy
II. Nuclear Physics
1.
2. Mössbauer spectroscopy
3. Alpha spectroscopy
4. Gamma-gamma correlation
5. [Nuclear lifetime determination]
6. Time-of-flight of relativistic muons
III.
1. Optical Faraday effect in solids
2. Second harmonic generation
3. [Four wave mixing]
4. Laser basics: spectra, power, polarization, divergence, stabilization
5. Holography
6. Hall Effect in thin films
7. High Tc superconductivity and SQuIDs
8. X-ray diffraction
9. Scanning-tunneling microscopy
10. Child’s law and automated control of experiments using LabVIEW
Notebook:
Activity in this
course must be documented comprehensively, neatly, and immediately
in a National 43-648 notebook. Daily entries should record your
progress, explanations, references, and so forth. For each experiment, the notebook should
include (1) a statement of the primary and secondary objectives of the
experiment, (2) a complete record of your activities, (3) diagrams and
narrative describing the experiment (in enough detail to permit reconstruction
of the experiment), (4) data tables, graphs, and/or references to data files,
(5) uncertainty considerations, and (6) conclusions.
Dialogues:
Students in this course must have two “informal dialogues”. Thirty to sixty minute dialogues, conducted as if the instructor were a visiting physicist, require clear and concise explanations of the crux of the experiments, recent progress, etc. Students should schedule dialogues only when they understand the essence of an experiment and only when prepared to answer authoritatively obvious questions; notes are not allowed.
Presentation of PRL Articles:
Each student must select an article from a recent (within the last five years) issue of Physical Review Letters and make a 10-minute presentation on it. These presentations should serve to explain the main results reported in the letter. The selected article must focus on experimental results as opposed to theoretical or computational results. Physical Review Letters is the premier (American) physics journal where the most significant and recent results are reported in short articles (i.e. "letters"). Presentations will be scheduled in weeks 2 and 3 (see below).
There will be a regular 45-minute discussion of reading from Experiments in Modern Physics, by Mellisinos and Napolitano (hereafter referred to as M&N). A student will be the assigned as discussion leader for each session. The instructors will advise discussion leaders as to the sections of the reading that are to be emphasized. All students should come to these discussions having read the assigned sections and prepared to ask questions and respond to questions from his or her classmates.
Colloquium Attendance:
Each student must attend at least three colloquia during the term. For each colloquium attended the student must prepare a half to one-page summary of the talk. Physics colloquia are preferred but Chemistry, Biology, Geology, and Science Hall Colloquia attendance will be accepted in satisfaction of this requirement. The purpose of this requirement is for students to observe scientific presentations in order to improve their own oral presentation skills. The student should pay attention not only to the scientific content of each talk, but also the organization and style of presentation.
Oral Communication:
This course is designated as “speaking intensive” and satisfies the corresponding general education requirement. Effective oral communication is a crucial skill for the practicing physicist. In this course, students’ oral communication skills will be improved and evaluated as part of the following required elements of the course: (1) presentation of a Physical Review Letter, (2) a formal scientific presentation, (3) two informal dialogue sessions, and (4) the leading and participating in discussion of reading assignments. Required colloquium attendance serves to provide examples of scientific presentations whether good, bad or mediocre.
Course Schedule
Week 1
·
MONDAY: Choose
primary experiment and make tentative choice of the second. Begin reading
background material on first experiment.
Get familiar with hardware for first experiment.
·
WEDNESDAY:
Physics journals and library databases.
We will meet in the CPL to discuss physics journals and electronic
databases for tracking down physics articles.
Make interlibrary loan requests
for first experiment by the end of the week 1! Begin work on first
experiment in earnest.
·
FRIDAY: Read and discuss (1) the page on
Radiation Safety Considerations (attached to this syllabus), (2) the catalog of
radioactive sources (attached to this syllabus), (3) Appendix D from Mellisinos
(Radioactivity and Radiation Safety, pp.485-488), (4) Appendix C from
Mellisinos (Laser Safety, pp.483-484) and (5) Questions and Answers on Eye
Safety with Laser Systems (attached to this syllabus). View laser safety video.
Continue work on first experiment.
Week 2
·
MONDAY: Discuss M&N Chapters 1&2 (Experiments on Quantization and Electrons in Solids). Discussion leaders are Ms. Marler (Ch.1) and
Mr. Stoneking (
·
WEDNESDAY: Read sections 1.1-1.2 of Building Scientific Apparatus (pp. 1-19,
Tools and Shop Processes; Materials).
First machine shop session. Continue work on first experiment.
·
FRIDAY: Skim section 1.4 of Building Scientific Apparatus (pp. 28-37, Mechanical Drawing). Second machine shop session. Continue
work on first experiment.
Week 3
·
MONDAY: PRL
presentations (Exharhos, Garbacik, Hawley). Continue work on first
experiment.
·
WEDNESDAY: PRL
presentations (Schneck, Weiss). Continue work on first experiment
·
FRIDAY: Continue work on first experiment.
Week 4
·
MONDAY: First
dialogue. Continue work on first
experiment.
·
WEDNESDAY: Discuss M&N Chapter 3&4 (Electronics and Data Acquisition and Lasers).
Discussion leader is Claire Weiss.
Continue
work on first experiment.
·
FRIDAY: Wrap up first experiment. Notebooks
are due at completion of first experiment.
Begin drafting paper. Read sections I and II (pp. 1-11) of the AIP Style Manual. Skim the rest of this document as needed
while you write your paper. Discuss physics literature.
Week 5
·
MONDAY: Discuss M&N chapter 5 (Optics Experiments). Discussion leader is Maureen Schneck. Begin work
on second experiment.
·
WEDNESDAY: Continue work on second experiment.
·
FRIDAY:
Continue work on second experiment.
Week 6
·
MONDAY:
Skim and discuss section 1.3 of Building
Scientific Apparatus (pp. 19-28, Joining materials). Soldering and welding demonstration. Continue work on second experiment. : First
draft of paper due
·
WEDNESDAY: Discuss M&N chapter 6 (High-Resolution spectroscopy). Discussion leader is Chris Hawley. Continue work
on second experiment.
·
FRIDAY: Midterm Reading Period. No Class.
Week 7
·
MONDAY: Discuss M&N chapter 7 (Magnetic Resonance Experiments). Discussion leader is Erik Garbacik. Continue work on second experiment.
·
WEDNESDAY: Wrap up work on second experiment. Notebooks are due at completion of second
experiment. Begin preparing oral
presentations.
·
FRIDAY: Begin work on third experiment.
Week 8
·
MONDAY: Discuss M&N chapter 8 (Particle Detectors and Radioactive Decay). Discussion leader is Annemarie Exarhos. Final draft of paper due. Continue work
on third experiment.
·
WEDNESDAY: Continue work on third experiment.
·
FRIDAY: Continue work on third experiment.
Week 9
·
MONDAY: Discuss
M&N chapters 9&10 (Scattering and
Coincidence Experiments and Elements
from the Theory of Statistics). Discussion
leaders are Ms. Marler (Ch. 9) and Mr. Stoneking (
·
WEDNESDAY: Begin work on fourth experiment.
·
FRIDAY: Oral
presentations
Week 10
·
MONDAY: Memorial Day. No class.
·
WEDNESDAY: Second
dialogue. Continue work on fourth experiment.
·
FRIDAY: Wrap up fourth experiment. Notebooks
are due TODAY.
Objectives: To employ the Mössbauer
effect to investigate (1) the structure of the 14.4 Kev emission line emitted
by 57Fe nuclei imbedded in a
Cu matrix, (2) the lower limit of the lifetime of the 14.4 Kev excited state
of 57Fe using an
isotopically-enriched stainless steel absorber, (3) the comparative widths of
the absorption lines of 57Fe
imbedded in K4Fe(CN)6.3H20
and 310 stainless steel, (4) the isomer shift between 57Fe lines for
310 stainless steel and other absorbers, (5) the hyperfine structure of 57Fe in natural iron, and (6)
the Mossbauer spectra of 57Fe
imbedded in other materials.
References: Melissinos, Experiments in Modern Physics
Mössbauer Effect, Selected Reprints
Frauenfelder, The Mössbauer Effect
Procedure: Using the Austin Science
linear drive and controller, a Reuter-Stokes proportional detector, a chain of
NIM instrumentation (preamplifier, amplifier, single-channel analyzer, Canberra
Genie-2000 MCS, and high voltage source), observe the Mössbauer spectrum
of 57Fe in type 310 stainless
steel (use the 92% enriched stainless foil).
Using an MCA, develop a systematic procedure to choose SCA discriminator
settings that maximize the signal-to-background ratio of the absorption signal. Then observe the absorption of 57Fe in natural iron (again using a 92% enriched sample foil). As an extension, you might investigate the
Mössbauer spectrum of other iron-containing compounds and/or minerals such as
garnets, biotite mica, etc.
ELECTRON PARAMAGNETIC RESONANCE
Objectives: To investiage electron
paramagnetic resonance (EPR) in one or more materials to reinforce one's
understanding of (1) the Zeeman effect, spin angular momentum, spin flipping,
perturbative effects, Bloch equations, and crystal field concepts, (2) the use
of microwave techniques and microwave components at X-band frequencies, (3) the
use of ac techniques (in this case magnetic field modulation) for signal
display/enhancement and perhaps phase-sensitive detection (using a lock-in
amplifier), and (4) the measurement of g-values of the semi-free electrons in
the radicals DPPH, Cr-doped Mg0, and other samples.
References: Ingram, Free Radicals
Melissinos, Experiments in Modern Physics
NMR & EPR, Selected Reprints
Pake, Paramagnetic Resonance
Procedure: Using first a klystron,
attenuator, magic-T, slow-wave structure or cavity, crystal detectors and a
frequency counter, observe EPR signals in DPPH and carbazyl. Then use a lock-in amplifier to improve the
sensitivity of your EPR spectrometer. Vary
the modulation amplitude and frequency, power level, etc. to investigate the
signal dependence (or lack thereof) on these parameters. Consider locking the klystron to the cavity
or using NMR to determine the magnetic field.
Then shift to the Bruker EPR spectrometer, which provides much greater
sensitivity and control. Attempt to
observe EPR of in various other materials.
Measure the g-values to the highest possible precision and accuracy.
TIME-RESOLVED
LASER SPECTROSCOPY: QUANTUM BEATS
Reference: Study and follow the
detailed set of instructions in the red binder and Brandenberger's discussion
of quantum beats in his Report. This experiment employs an N2-pulsed
laser which pumps a Littman-Metcalf tunable dye laser. The main purpose of this experiment is to
acquaint the student with fluorescence spectroscopy, the classical and quantum
interpretations of quantum beats, and a pulsed tunable laser system.
OPTICAL
PUMPING OF RUBIDIUM
Objectives: To investigate various
facets of optical pumping in rubidium by (1) observing the disorientation of
optically pumped/oriented Rb vapor due to radio-frequency magnetic resonance
and/or rapid passage through zero magnetic field, (2) observing the linear and
quadratic Zeeman effects in Rb, (3) determining the Lande g-factors and
confirming the values of nuclear spin for 85Rb and 87Rb,
(4) studying the transient phenomena when the rf field is amplitude modulated
at a fixed value of magnetic field, (5) observing the magnetic resonance
linewidth as a function of rf field strength and light intensity, (6) observing
multi-quantum rf resonances, and (7) determining the disorientation relaxation
time and pumping-up times.
References: B. Smith, Honors Thesis,
Lawrence University (1969)
De Zafra, Am. J. Phys. 28,
646 (1960)
Benumof, " "
" 33, 151 (1965)
Nagel & Haworth, Am. J.
Phys. 34, 553 (1966)
Happer, Rev. Mod. Phys. 44,
169 (1972)
Masers and Optical Pumping, Selected Reprints
Bernheim, Optical Pumping: An
Introduction
Procedure: Following the set of
instructions in the red binder, recreate the various optical pumping lineshapes
displayed there. Let this experiment
reinforce physically various topics that you encountered in Physics 31.
COMPTON EFFECT EXPERIMENT
Objectives: To investigate Compton
scattering to (1) learn scintillation spectroscopy and the use of a
multichannel analyzer, (2) verify the predicted shift of the Compton peaks with
angle, (3) infer the rest mass mo of the scattering electron,
(4) attempt to verify the Klein-Nishina formula, and (5) investigate the energy
shift of the peak of the electron recoil spectrum.
References: Shankland, Scientific Papers of A. H. Compton (esp. articles on pp. 82 and 414)
Melissinos, Experiments in Modern Physics
Semat,
Introduction to Atomic and Nuclear Physics
Siegbahn, Alpha, Beta, and Gamma-Ray Spectroscopy
Richtmeyer, Kennard, and
Cooper, Introduction to Modern Physics
Procedure: In performing this
experiment, concentrate first on the shift
of the 0.662 KeV 137Cs photopeak as a function of scattering
angle q. Use a
l" diameter Al rod as the scattering target, a 2" diam NaI(Th)
scintillation detector composed of a NaI crystal and photomutiplier, and a
PC-based Genie-2000 multichannel analyzer.
Then repeat the experiment focusing upon the intensity of the scattering peak as a function of q to test the Klein-Nishina
formula. Next investigate the Compton
scattering as a function of target Z.
Include corrections for MCA calibration, zeroing, detector efficiency,
target geometry, beam profile, etc. You
might attempt to reconfigure the experiment by using coincidence techniques.
OPTOGALVANIC LASER
SPECTROSCOPY
Objectives: To exploit the optogalvanic
effect in a discharge to investigate (1) the energy levels and populational
dynamics of atomic neon and argon, (2) the use of an argon-pumped tunable dye
laser for laser spectroscopy, and (3) the use of ac techniques and lock-in
detection.
Procedure: Look at Lawler's review
article and past student papers in the red binder.
NUCLEAR MAGNETIC
RESONANCE EXPERIMENT
Objectives: To investigate nuclear
magnetic resonance in liquids to (1) reinforce one's understanding of the
nuclear Zeeman effect, angular momentum, spin precession, spin flipping,
perturbative effects, Bloch equations, etc., (2) become acquainted with the
operation and performance of a marginal oscillator, (3) gain appreciation of ac
techniques (in this case magnetic field modulation) and signal enhancement
through signal averaging and/or lock-in amplification, (4) become adept at
measuring magnetic fields to high precision via NMR, (5) attempt to understand
the transient effects associated with rapid passage through the resonance
condition, and (6) investigate saturation effects and relaxation times.
References: Melissinos, Experiments in Modern Physics
Andrew, Nuclear Magnetic Resonance
Abragam, The Principles of Nuclear Magnetism
NMR and EPR, Selected Reprints
Brandenberger, Laboratory Computing
Procedure: Use the permanent magnet
setup to observe the rapid passage NMR signal.
Investigate the effects of paramagnetic doping on the relaxation times.
ALPHA SPECTROSCOPY
Objectives: To investigate
alpha-particle emission via charged particle spectroscopy using a passivated
implanted planar silicon (PIPS) detector in a light-tight evacuated
chamber. The aims of this experiment are
(1) to become acquainted with the PIPS detector, (2) to perform
charged-particle spectroscopy with a multichannel analyzer, (3) to study the
natural radioactive decay chains, and (4) to infer the spectral effects of
coverings laid over alpha sources.
References: Melissinos, Experiments in Modern Physics
Canberra
Laboratory Manual
Procedure: Carefully read and
diligently observe the precautions regarding the application of vacuum, light,
and increasing voltages to the PIPS detector.
For an initial spectrum and calibration purposes, use the 241Am source; then move on to the alpha sources removed
from smoke detectors and the new multi-line alpha source. Do not
touch the gold-plated top surface of the latter.
SECOND HARMONIC
GENERATION EXPERIMENT
Objectives: To investiage the
non-linear optical effect known as second harmonic generation, by which process
light of a given frequency is "doubled" to produce light of exactly
twice the frequency (or one-half the wavelength).
References: Bloembergen, Non-Linear Optics
Giordmaine, "The Interaction of Light with
Light"
Franken and Ward, "Optical Harmonics and Nonlinear
Phenomena"
Procedure: Use the Coherent 599 cw
dye laser for excitation, a KDP crystal for doubling, and a solar-blind
photomultiplier for separation of the second harmonic from the fundamental.
Investigate polarization effects and the dependence of the SHG conversion
efficiency on angle tuning and laser focussing.
SATURATED ABSORPTION LASER SPECTROSCOPY
Objectives: To use saturated
absorption laser spectroscopy to investigate (1) the hyperfine structure of the
ground and first excited states of 85Rb and 87Rb, (2) Doppler-free spectroscopy, (3) the isotope shift of the
energy levels of Rb, (4) polarization and power-broadening effects in saturated
absorption, and (5) the use of diode lasers in atomic spectroscopy.
Procedure: Follow the detailed set
of instructions in the red binder and study Brandenberger's Report for a discussion of saturated
absorption and the experimental layout.
Look at Camparo's review of diode lasers and past student papers on this
experiment.
FARADAY EFFECT EXPERIMENT
Objectives: To investigate the Faraday
effect whereby the plane of polarization of a beam of linearly polarized light
rotates as the beam propagates through some material in the direction of a
large, externally applied magnetic field.
The aim here is to measure Verdet constants, which characterize the
strength of the Faraday effect in different materials at different wavelengths.
References: Jenkins and White, Fundamentals of Optics
Hecht, Optics
Procedure: Following DeMets and
McDonough and other past students, use the cubic samples of heavy and light
flint glass, polaroid polarizers, a 4" electromagnet, and HeNe lasers that
lase at different wavelengths. Other
materials should then be investigated at different wavelengths.
LASER BASICS EXPERIMENT
Objectives: To investigate laser
operation and behavior with particular emphasis upon (1) discharge and cavity
characteristics, (2) cavity adjustment and alignment, (3) power optimization,
(4) output beam profile and polarization, (5) use of a spectrum analyzer to
explore the stability and longitudinal and transverse mode relationships, (6)
use of piezo elements and external circuitry to stablize a laser, (7)
techniques for achieving single-mode operation, (8) introduction of
intra-cavity elements, and (9) use of an external plane-parallel Fabry-Perot
cavity.
References: O'Shea and Peckham, Lasers:
Selected Reprints
O'Shea, Callen & Rhodes, Introduction to Lasers and Their
Applications
Lasers and Light (Scientific American
Reprints)
Brandenberger, Proceedings and Report
Procedure: After a preliminary reading
of some of the references, investigate the starting, operation, and adjusting
of the lasers, especially for maximization of power. Exercise great care and respect for your eyes
(and those of others), the spectrum analyzer, and laser power meters. Look at the mode profiles and ascertain how
you can favor one mode at the expense of others. Move on to mode analysis using the spectrum
analyzer; try pulling the laser with the
piezo elements. From here on the
experiment is open-ended; many things
are possible.
SUPERCONDUCTIVITY
Reference: Look at the Conductus
manual for an introduction to various experiments that can be performed with
Mr. Squid.
GAMMA-GAMMA CORRELATION EXPERIMENT
Objectives: To investigate the
correlation of gammas emitted by electron-positron annihilation and/or the
rapid two-photon cascade decay of 60Co. A practical objective of this experiment is
to become familiar with scintillation spectroscopy, NIM instrumentation, and
coincidence techniques.
References: Melissinos, Experiments in Modern Physics
Seaman,
Siegbahn, Alpha, Beta, and Gamma-Ray Spectroscopy
Procedure: Use the needle-shaped 22Na positron source to set up the standard gamma-gamma correlation
experiment. Use this arrangement to
become familiar with the SCAs and coincidence module; use a Canberra MCA to set the discriminator
windows. Take enough data to verify the
strong directional correlation of the annihilation gammas. Think about the idealized
"lineshape" for the angular distribution of these gammas assuming a line source and narrow rectangular apertures in front of the
detectors. Think about the effect that
an extended source would have on this lineshape. Think about the lineshape effects due to
decaying positronium not initially at
rest in the lab. Use the same
apparatus but 60Co to pursue a more difficult
gamma-gamma correlation.
X-RAY DIFFRACTION EXPERIMENT
Objectives: To learn x-ray
diffraction methods to examine the structure and correlations in solids and
fluids. Use x-rays to study crystalline
(Al) and amorphous (glass) materials.
References:
Ashcroft and Mermin,
Procedure: After reading appropriate
sections of the recommended references, determine what one should expect when
x-rays are scattered from a target of polycrystalline aluminum. After making a sketch of the diffraction
process on the Siemens x-ray diffractometer, collect a diffraction pattern from
an aluminum foil sample and compare with your prediction. Follow this measurement with diffraction from
a piece of glass; develop a qualitative
interpretation of this pattern.
Extensions may include looking at liquid crystal phases and transitions
between them.
TIME OF FLIGHT OF
RELATIVISTIC MUONS
Objectives: To measure the time of
flight of relativistic muons (generated in the upper atmosphere by cosmic rays)
as they traverse the separation between two plastic scintillator paddles, to
become familiar with fast NIM electronics and a time-to-amplitude converter
(TAC), and to confirm indirectly Lorentz contraction or time dilation.
References: MIT Junior Laboratory
Instruction Set for this experiment