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, 2^nd 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 (Laser Palace), 138 (CPL), or 104 (Physics Commons). These resources are irreplaceable and hence cannot leave the department. This course employs a large collection of equipment, NIM modules, multichannel analyzers, digital oscilloscopes, PCs with GPIB interfaces, electronic and optical instrumentation, vacuum hardware, lasers, machine shop tools, the CPL, and on-line literature searching. Physics 330 attempts to acquaint you with these items; notebook entries should confirm this fact.

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 Lawrence) developed by the student. The paper should include references to primary literature and show evidence that the student has done the necessary background reading to place his or her experiment in its proper context in the field of physics.

· 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. Compton scattering

2. Mössbauer spectroscopy

3. Alpha spectroscopy

4. Gamma-gamma correlation

5. [Nuclear lifetime determination]

6. Time-of-flight of relativistic muons

III. Solid State Physics and Miscellaneous

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).

Reading and Discussion:

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 (Ch. 2). Continue work on first experiment.

· 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 (Ch. 10). Wrap up work on third experiment. Rehearse oral presentations

· 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.

MÖSSBAUER EXPERIMENT

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 m_o 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, Canberra Laboratory Manual

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: Preston and Dietz, The Art of Experimental Physics, p. 180-192

Ashcroft and Mermin, Solid State Physics

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

Canberra NIM Manual