Research Projects

Project 1: Computed Tomography, A Proof of Concept (2025)

• Computed Tomography Imaging: Constructed a first-generation CT scanner setup using visible light to generate 2D and 3D reconstructions of cylindrical and triangular prism samples.

• Optical Setup Design: Aligned a HeNe laser (632.8 nm), convex lens, linear polarizers, and beam expander to optimize light detection with a photodiode

• Data Acquisition: Manually collected light intensity data using LoggerPro software, accounting for angular and linear movements of samples.

• Image Processing: Applied Simple Back Projection (SBP) and Filtered Back Projection (FBP) with a ramp filter using Python libraries (matplotlib, skimage, numpy).

• Radon Transform Application: Utilized the Radon transform and projection-slice theorem to convert illumination data into sinograms for image reconstruction.

• 3D Modeling: Stacked 2D cross-sectional images to create 3D reconstructions of samples, improving resolution through data interpolation

• Symmetry Utilization: Leveraged radial symmetry of cylindrical samples to reduce data collection time via interpolation.

• Error Analysis: Quantified illumination measurement uncertainties (±0.5 to ±20 lux) based on light intensity conditions.

• Opto-Mechanical Assembly: Secured components on an optical breadboard, using screws and clamps to stabilize the setup.

• Problem Solving: Adapted the experimental design due to equipment limitations, incorporating a cloth to reduce ambient light noise and polarizers to prevent detector saturation.

Project 2: Digital Sunflower using a Feedback Control System (2024)

• Feedback Control Systems: Designed a real-time light-tracking system using LDR feedback to control servo motors.

• Arduino Programming: Developed code with PWM for precise servo control and LDR voltage comparisons.

• Circuit Design: Built and tested four-stage voltage divider circuits with LDRs for light detection.

• Mechanical Design: Engineered a 3D-printed chassis with orthogonal servos for dualaxis motion.

• Data Acquisition: Measured LDR voltages and servo angles, logged via Arduino’s Serial Monitor.

• Data Analysis: Used Python to plot sinusoidal LDR responses and validate light intensity gradients.

• Optics Knowledge: Applied principles of electric flux and light intensity to interpret LDR behavior.

• Problem-Solving: Overcame servo saturation, loose connections, and noise with software and hardware fixes.

• Electronics: Soldered connections and resolved ground loop issues for stable circuit performance.

• Technical Writing: Documented system design, results, and challenges in a comprehensive

  report

Physics Labs

PHY 3904 - Physics and Applied Physics Laboratory II

Experiment 1: Low-level Signal Detection, Exploring the Oscilloscope and The Lock-In Amplifier (LIA)

• Signal Processing: Utilized lock-in amplifiers (SR510/SR530) to extract low-level signals from noisy environments.

• Oscilloscope Operation: Configured Agilent DSO1012A oscilloscope for time-scale, XY, and FFT analysis to measure signal frequency and phase.

• Circuit Configuration: Designed circuits with function generators, LEDs, speakers, and high-resistance loads for signal detection experiments.

• Phase Measurement: Adjusted LIA phase settings to monitor phase shifts and calculate the speed of sound in air.

• Noise Reduction: Employed optical choppers to modulate light signals, minimizing interference from stray light sources.

• Low-Level Current Measurement: Used Keithley picoammeter and LIA to detect picoampere-level currents from LED receivers.

• Data Acquisition: Monitored and recorded signals using oscilloscopes, digital multimeters, and LIA outputs.

• Frequency Analysis: Applied function generators to produce modulated signals and analyzed frequency limits in sound experiments.

• Error Analysis: Estimated uncertainties in speed of sound measurements and compared results with theoretical values.

• Instrument Calibration: Set appropriate sensitivity scales and time constants on LIAs to avoid signal overloading.

Experiment 2: Electrical Transport Measurements

• Semiconductor Characterization: Measured resistivity and Hall voltage to determine band gap and charge carrier density in a semiconductor.

• Hall Effect Measurement: Observed transverse voltage under magnetic fields to study charge carrier behavior.

• Cryogenic Techniques: Used liquid nitrogen (77.2 K) and a Janis Optical Cryostat for low-temperature experiments.

• Vacuum Technology: Maintained a high vacuum (10 hPa) using a HiCube Pfeiffer Diffusion Pump for precise temperature control.

• Data Acquisition: Configured NI LabVIEW with GPIB-to-USB interfaces for automated resistivity and voltage measurements.

• Instrument Calibration: Calibrated a Platinum Resistor Thermometer (Pt-100) and Gaussmeter Probe for accurate temperature and magnetic field readings.

• Circuit Design: Built and verified ohmic contacts using a DC power supply and Keithley 2700 multimeter, confirming Ohm’s Law.

• Magnetic Field Generation: Operated electromagnets with iron cores to produce uniform fields up to 152.6 mT, applying safe voltage ramping.

• Error Analysis: Identified anomalies in Hall voltage data due to loose contacts or wiring issues, proposing calibration improvements.

• Solid State Physics: Applied band gap theory and Lorentz force principles to interpret exponential resistivity decay and Hall voltage trends.

Experiment 3: Light Spectroscopy

• Light Spectroscopy: Recorded and analyzed emission spectra of Ne and Na lamps using a high-resolution spectrograph.

• Detector Calibration: Calibrated CCD and Si PIN diode detectors with Ne lamp spectra across multiple diffraction gratings.

• Spectral Analysis: Measured Na doublet wavelengths and compared with accepted values to assess grating resolution.

• Optical Setup: Designed and built front optics to focus light onto the spectrograph’s entrance slit.

• Low-Level Signal Detection: Used a Stanford Research SR510 lock-in amplifier to record low-level light signals in scanning mode.

• Data Acquisition: Configured LabVIEW for automated spectral data collection and time-scale calibration.

• Semiconductor Characterization: Determined band gap energy of a semiconductor through light absorption measurements.

• Instrument Operation: Adjusted spectrograph slit widths to study effects on spectral linewidth and resolution.

• Opto-Mechanical Assembly: Utilized optical breadboards and components for precise alignment in spectroscopy setups.

Experiment 4: Gamma-Ray Spectroscopy

• Gamma-Ray Spectroscopy: Recorded and analyzed gamma-ray spectra using Ge and NaI(Tl) detectors with a multichannel analyzer.

• Detector Calibration: Calibrated energy scales for Ge and NaI(Tl) detectors using radioactive sources and GENIE software.

• Pulse Height Analysis: Performed pulse height analysis to interpret gamma-ray spectra and identify isotope-specific energy peaks.

• Compton Scattering Analysis: Measured electron rest mass via Compton edge analysis, applying special relativity principles.

• Radiation Safety: Handled radioactive sources and lead safely, adhering to protocols for high-voltage equipment and low-activity materials.

• High-Voltage Electronics: Operated detectors at high voltages (up to +4500 V), ensuring gradual voltage adjustments to prevent damage.

• Signal Processing: Adjusted pulse shaping times and amplifier settings to optimize peak shape and line resolution.

• Background Radiation Analysis: Identified isotopes in background radiation spectra collected over extended periods.

• Data Acquisition: Used oscilloscopes and multichannel analyzers to collect and store spectral data in .cnf and .tka formats.

• Comparative Analysis: Compared Ge and NaI(Tl) detector performance in terms of efficiency, linewidth, and spectral resolution.

Experiment 5: Michelson Interferometry

• Michelson Interferometry: Built and aligned a Michelson interferometer to measure light wavelengths and refractive indices.

• Optical Alignment: Precisely aligned laser beams, beamsplitters, and mirrors using a He-Ne laser for optimal interference patterns.

• Fringe Analysis: Counted interference fringes to calibrate digital indicators and measure optical path differences.

• Refractive Index Measurement: Determined indices of refraction for glass and gases (air, argon, helium) via fringe shifts with rotation stages and gas cells.

• Wavelength Determination: Measured the Na doublet wavelengths and their separation through beat pattern analysis.

• Precision Instrumentation: Operated micrometric screws, picomotors, and digital gauges for sub-micron mirror adjustments.

• Laser Safety: Applied laser safety protocols when handling He-Ne lasers and Na lamps.

• Gas Handling: Safely managed high-pressure gas cylinders and hand pumps to control gas cell pressure.

• Data Acquisition: Used computer interfaces to record fringe counts and pressure sensor data with uncertainty propagation.

• Opto-Mechanical Setup: Assembled optical components on a breadboard, ensuring clean handling of delicate surfaces.

Experiment 6: Nuclear Magnetic Resonance (NMR)

• Pulsed NMR Operation: Configured and operated a TeachSpin PS1-A spectrometer to generate RF pulses and detect NMR signals.

• Pulse Sequence Design: Implemented Pi/2 and Pi pulse sequences to measure T1 and T2 relaxation times via FID and spin echoes.

• Signal Detection: Used pickup coils and receiver circuits to observe FID and spin echo signals on an oscilloscope.

• RF Electronics: Tuned 15 MHz oscillator and amplifier for precise RF pulse generation and minimized mixer beat frequencies.

• Relaxation Time Measurement: Accurately measured T1 using the zero-crossing method and T2 via multipulse spin echo sequences.

• Material Characterization: Analyzed T and T for samples (e.g., mineral oil, water, glycerine) to study spin dynamics.

• Phase Transition Analysis: Investigated NMR signal changes in paraffin during solid-to-liquid phase transitions.

• Doping Effects: Measured T1 and T2 variations in water with CuSO doping to study paramagnetic ion effects.

• Diffusion Studies: Explored spin echo amplitude decay due to molecular diffusion in non-uniform magnetic fields.

• Data Acquisition: Utilized oscilloscope cursor measurements and LabVIEW interfaces for precise time and voltage data collection.

PHY 3902 - Physics and Applied Physics Laboratory I

Experiment 1: Introduction to Data Acquisition with Arduino, Sensors, and Motors

• Mastered the Arduino microcontroller platform, including its 10-bit resolution, pin functionality, and integration of various libraries in sketches for enhanced functionality.

• Implemented an external LED fading circuit using a light-dependent resistor (LDR) and pulse-width modulation (PWM), demonstrating control over analog output.

• Measured voltage across an LED using C code and the analogRead function, applying analog input techniques for precise sensor data acquisition.

• Automated the Google Dinosaur game by designing a system with an LDR sensor and servo motor to detect obstacles and simulate key presses, showcasing sensor-actuator integration.

• Optimized Arduino code and hardware setup to maximize performance in the Google Dinosaur game, achieving high scores through efficient programming and calibration.

Experiment 2: Characteristics of Light-Emitting Diodes (LEDs)

• Circuit Design: Built and analyzed voltage divider circuits with Arduino and DAC shield for LED testing.

• Arduino Programming: Wrote sketches for voltage sweeps and data acquisition using analogRead().

• Data Acquisition: Collected voltage/current data with uncertainties, exported to CSV.

• Data Analysis: Performed curve fitting and linear regression with Python’s scipy and pandas.

• Visualization: Created plots to visualize I-V relationships and threshold voltage trends.

• Physics Application: Applied Planck-Einstein relation to estimate Planck’s constant.

• Semiconductor Knowledge: Studied LED threshold voltages and wavelength-energy relationships.

• Error Analysis: Calculated propagated errors for measurements and curve fits.

• Technical Writing: Documented experimental methods, results, and conclusions in a lab report.

• Problem-Solving: Adjusted regression ranges to account for varying LED threshold voltages.

Experiment 3: Characteristics of a Laser Diode

• Optical Experiment Design: Configured setups to study laser diode polarization, reflection, and beam profiling.

• Arduino Programming: Developed sketches for stepper and servo motor control and LDR data acquisition.

• Data Acquisition: Measured voltage drops across LDR with averaging to reduce noise, exported to CSV.

• Data Analysis: Used Python to plot and fit data, verifying Malus’s Law and Brewster’s Angle.

• Polarization Physics: Applied Malus’s Law and Fresnel equations to analyze light behavior.

• Error Analysis: Calculated uncertainties from multiple measurements and identified calibration offsets.

• Electronics: Implemented voltage divider circuits with LDRs for light intensity measurements.

• Technical Writing: Co-authored a detailed lab report with clear methodology and results.

• Problem-Solving: Mitigated noise with opaque enclosures and addressed servo motor limitations.

• Optics Knowledge: Understood laser beam profiles and polarization effects in dielectrics.

Experiment 4: Servo Control Loops (Feedback Control Systems) – PID Temperature Controller

• Feedback Control Systems: Implemented and compared Hysteresis, P, PI, and PID control for temperature regulation.

• Arduino Programming: Wrote sketches to control heating elements and read thermistor data via MOSFET.

• Circuit Design: Configured voltage divider circuits with thermistors for temperature measurement.

• Data Acquisition: Collected temperature and power data, exported to CSV for analysis.

• Data Analysis: Used Python to plot temperature responses and calculate specific heat capacity.

• Thermal Physics: Measured aluminum’s specific heat capacity using energy transfer equations.

• Error Analysis: Quantified uncertainties in specific heat capacity measurements.

• Technical Writing: Documented control system performance and trade-offs in a lab report.

• Problem-Solving: Tuned PID parameters to optimize stability and minimize oscillations.

• Electronics: Integrated MOSFET for precise power control in heating applications.

PHY 2104 - Introduction to Circuit Theory and Electronics

Experiment 1: Introduction to measurements with NI ELVIS II+ and data analysis using Python

• DC Circuit Building: Constructed and troubleshot DC circuits on NI ELVIS II+ prototyping board, ensuring clean layouts and safe operation.

• Electrical Measurements: Utilized virtual instruments (DMM, VPS, 2-Wire) to measure voltage, current, and resistance, characterizing resistors and LEDs.

• Data Analysis: Analyzed I-V curves for resistors and diodes using a 2-Wire analyzer, determining resistance and diode offset voltage.

• Ohmic Theory: Applied Ohm’s Law to verify component behavior and assess electrical safety risks.

• Computation in Python: Performed data analysis and visualization in Python using Google Colab, numpy, scipy, and matplotlib, fitting linear models to experimental data.

Experiment 2: Equivalent Resistance and Introduction to AC measurements

• Stability Measurements: Measured load characteristics of a variable power supply (VPS), analyzing voltage vs. current to assess source stability.

• Equivalent Resistance: Determined equivalent resistance using Wheatstone bridge circuits,

  comparing results with DMM measurements and color code estimates for accuracy.

• Circuit Analysis Theory: Measured node voltages and mesh currents in DC circuits, applying circuit analysis techniques to verify theoretical values.

• Building Testing AC circuits: Investigated AC circuit behavior with voltage dividers, rectifiers (using LEDs), and opposing LED pairs, analyzing signal shapes and amplitudes at varying frequencies (1 Hz to 250 kHz).

• Semiconductor Concepts: Characterized rectifier circuits, measuring input/output peak-to-peak voltages and identifying threshold voltages for LEDs.

Experiment 3: Operational Amplifiers

• Variable Gain Amplifier Design: Mastered the construction and testing of both inverting and non-inverting operational amplifier circuits with adjustable gain using potentiometers and precision resistors.

• Frequency Response Analysis: Developed proficiency in characterizing op-amp performance across frequency ranges (1-10 kHz), measuring phase shifts and gain variations using oscilloscope techniques.

• Saturation Voltage Characterization: Acquired expertise in determining op-amp saturation limits under varying supply voltages (±8V to ±10V), understanding dynamic range limitations.

• Gain-Bandwidth Product Measurement: Gained skills in evaluating comparative performance between LM741 and LF356 op-amps, calculating cutoff frequencies and bandwidth characteristics.

• Error Propagation Analysis: Mastered uncertainty calculations for electronic measurements,

  applying statistical methods to assess measurement accuracy and validate experimental results.

• Circuit Troubleshooting: Developed diagnostic skills in identifying faulty components (defective op-amps), implementing component replacement, and verifying circuit functionality.

Experiment 4: Building and Testing a Discrete Operational Amplifier

• Soldering Techniques: Developed hands-on soldering skills for electronic components and PCB assembly, constructing a complete discrete operational amplifier circuit.

• Inverting Amplifier Configuration: Gained proficiency in building and testing inverting amplifier circuits with variable feedback resistances, analyzing gain characteristics and circuit behavior.

• Electronic Measurement Techniques: Acquired expertise in voltage and current measurements using laboratory instrumentation to characterize op-amp performance and validate circuit functionality.

• Op-Amp Ideality Assessment: Mastered evaluation of operational amplifier characteristics including input current analysis and deviation from ideal behavior.

• Circuit Analysis and Validation: Developed skills in systematic data collection, gain calculations, and linearity assessment for analog electronic circuits.

• Laboratory Setup: Configured test equipment and measurement systems for precise characterization of discrete operational amplifier performance across multiple operating conditions.

Experiment 5: Transient Response of First-Order RC and Second-Order RLC Circuits

• Time Constant Measurement: Mastered characterization of first-order RC circuits with varying capacitance values (47 nF to 0.47 μF), measuring transient response times and maximum frequency behavior.

• Op-Amp Integrator Analysis: Developed proficiency in constructing and testing both ideal and practical op-amp integrator circuits, analyzing DC offset effects and signal integration for sinusoidal and square wave inputs.

• Second-Order System Characterization: Gained expertise in analyzing RLC circuit damping behaviors including under-damped, critically-damped, and over-damped responses through systematic resistance and capacitance variation.

• Oscillation Period Analysis: Acquired skills in measuring oscillation periods and cycle counting for under-damped systems, correlating damping coefficient changes with circuit component values.

• Frequency Response Testing: Mastered evaluation of circuit behavior across frequency ranges, identifying maximum operating frequencies and high-frequency roll-off characteristics.

• Transient Signal Analysis: Developed expertise in using oscilloscope techniques to capture and analyze transient waveforms, measuring rise times, settling behavior, and steady-state responses in reactive circuits.

Experiment 6: Filters and Transfer Functions

• Filter Circuit Design: Mastered construction and analysis of first-order RC filter circuits with varying capacitance values, characterizing low-pass and high-pass filtering behaviors across frequency ranges.

• Transfer Function Analysis: Developed proficiency in measuring and analyzing transfer functions of electronic filters, determining cutoff frequencies and frequency response characteristics through systematic testing.

• Active Filter Implementation: Gained expertise in designing op-amp based active filters, comparing ideal versus practical integrator performance with sinusoidal and square wave inputs.

• Second-Order Filter Characterization: Acquired skills in analyzing RLC filter circuits, measuring quality factors, resonant frequencies, and damping effects through component variation techniques.

• Frequency Domain Measurements: Mastered use of oscilloscope and function generator for frequency sweep analysis, measuring amplitude and phase responses across multiple decades of frequency.

• Filter Performance Evaluation: Developed techniques for assessing filter selectivity, roll-off rates, and passband characteristics, correlating theoretical predictions with experimental measurements.

PHY 2311 - Waves and Optics

Experiment 1: Wave Simulations in Python

• Python Programming: Gained proficiency in using Python libraries (Matplotlib, NumPy) for mathematical operations, loops, and plotting static and dynamic graphs in physics simulations.

• Harmonic Wave Simulation: Learned to simulate a harmonic wave (ψ(x) = Acos(kx)) with given parameters (λ = 6 cm, A = 2 cm), plotting over three cycles with Δx = 0.1 cm.

• Beat Signal Analysis: Developed skills in simulating beat signals from two harmonic waves, deriving and plotting their superposition over five cycles.

• Standing Waves Modeling: Mastered modeling standing waves on a string (L = 16 cm) from two counter-propagating harmonic waves, calculating harmonic mode wavelengths and frequencies.

• Fourier Analysis: Learned to apply Fourier theorem to represent a square pulse as a sum of harmonic modes, computing Fourier coefficients simulating for varying harmonic terms (N = 1, 3, 5, 11, 100).

• Gaussian Wave Packet Animation: Acquired expertise in simulating and animating a Gaussian wave packet at multiple time points and over a 1-minute interval.

• Data Visualization: Enhanced ability to create clear, accurate plots for wave phenomena, including static graphs for harmonic modes and dynamic animations for wave propagation

Experiment 2: Fresnel Reflection

• Fresnel’s Equations: Mastered the use of Fresnel’s equations for reflection coefficients to analyze light reflection at air-dielectric interfaces.

• Brewster Angle Determination: Gained proficiency in measuring the Brewster angle (tan θB = n) to determine the refractive index of a material, where parallel-polarized light reflection is zero.

• Polarization Effects: Learned to measure reflection coefficients for parallel (∥) and perpendicular (⊥) polarizations over a range of incidence angles (15° to 75°), using a diode laser and silicon photocell.

• Experimental Setup: Developed skills in configuring an optical system with a prism table, polarizer, and photocell circuit to accurately measure reflected light intensity and angles.

• Data Analysis: Acquired expertise in plotting reflection coefficients versus incidence angle, comparing results with Fresnel’s predictions.

• Surface Quality Control: Understood the importance of maintaining clean, scratch-free reflecting surfaces to ensure accurate measurements, addressing potential sources of error.

• Safety Practices: Learned to safely handle diode lasers, avoiding direct beam exposure and using paper to view beam images.

Experiment 3: Geometrical Optics - Lens Systems

• Lens Equation Application: Mastered the thin lens equation to determine

  focal lengths and image distances for single and compound lens systems.

• Focal Length Measurement: Gained proficiency in measuring focal lengths of converging

  lenses using three methods: (a) graphing (b) displacement method for fixed object-image distance L > 4f, and (c) self-conjugate point method with a pin and mirror.

• Diverging Lens Analysis: Learned to measure the focal length of a diverging lens by analyzing the shift in image position when combined with a converging lens, using the lens equation with virtual object distances.

• Compound Lens Systems: Developed skills in analyzing two-lens systems, calculating effective focal length, and focal point positions.

• Telescope Construction: Acquired expertise in constructing and characterizing astronomical and Galilean telescopes, estimating magnification visually and comparing with theoretical values based on focal lengths.

• Laser Beam Expansion: Learned to use a telescope as a laser beam expander, measuring beam expansion and validating results with calculations from lens focal lengths.

• Experimental Validation: Enhanced ability to compare experimental measurements of focal lengths and focal point positions with theoretical predictions, assessing optical system performance.

Experiment 4: Polarization

• Polarization Concepts: Learned the nature of light as a transverse wave, distinguishing linear, circular, and elliptical polarization based on electric field vector behavior.

• Malus’s Law Verification: Gained proficiency in demonstrating Malus’s law by measuring transmitted light intensity through polarizer-analyzer pairs at varying angles.

• Brewster Angle Measurement: Developed skills in determining the Brewster angle (tan iB = n) for complete polarization of reflected light, using reflection from a dielectric surface.

• Circular Polarization Production: Mastered producing and verifying circularly polarized light using a quarter-wave plate, observing phase differences (ϕ = π

  2 ) in birefringent crystals.

• Photoelasticity Observation: Learned to observe birefringence in strained plastics between crossed polarizers, understanding stress-induced optical anisotropy.

• Photocell Calibration: Acquired expertise in calibrating a photocell with a sodium lamp and neutral density filters, plotting current versus light intensity.

• Experimental Setup: Developed skills in configuring optical systems with polaroids, quarter-wave plates, and photocells to measure polarization effects accurately.

Experiment 5: Diffraction and Interference

• Diffraction Theory: Learned Fraunhofer diffraction principles for single slits, double slits, diffraction gratings, and circular apertures, understanding intensity distribution formulas.

• Single Slit Diffraction: Gained proficiency in measuring diffraction patterns from a single slit using a He-Ne laser (λ = 632nm), calculating slit width from angle measurements.

• Double Slit Interference: Developed skills in analyzing double-slit diffraction-interference patterns, determining slit width and separation from measured intensity distributions.

• Diffraction Grating Analysis: Mastered measuring grating constants by analyzing diffraction patterns, using angle measurements derived from distances on a viewing screen.

• Circular Aperture Observation: Acquired qualitative understanding of diffraction patterns from circular apertures, observing Airy disk patterns.

• Experimental Techniques: Learned to use a He-Ne laser and optical bench to project diffraction patterns, calculating angles via geometric measurements (distance ratios).

• Safety Protocols: Understood safe laser handling, avoiding direct beam exposure using paper to view diffraction patterns.

PHY 2361 - Modern Physics

Experiment 1: Planck’s Constant

• Photoelectric Effect: Learned Einstein’s photon theory, explaining photoemission properties (threshold voltage dependence on frequency, not intensity) via energy conservation (hf = eϕ + 1/2mv2).

• Experimental Setup: Gained proficiency in using a mercury lamp, direct vision prism, photocell, picoammeter, and voltmeter to measure threshold voltages for visible wavelengths

  (460–635 nm).

• Threshold Voltage Measurement: Developed skills in determining threshold voltages by plotting picoammeter current versus applied voltage, identifying slope changes to account for thermal and back-current effects.

• Planck’s Constant Determination: Mastered plotting threshold voltage versus frequency

  (f = c/λ) to derive Planck’s constant h from the slope h/e.

• Optical System Handling: Learned to configure an optical system with lenses and slits to minimize anode photoemission and filter harmful UV radiation from the mercury lamp.

• Data Analysis: Acquired expertise in interpreting current-voltage graphs, using tangent intersection methods to estimate threshold voltages accurately

• Safety Practices: Understood the importance of avoiding direct exposure to UV radiation and handling sensitive picoammeter circuits carefully.

Experiment 2: Electron Diffraction

• Wave-Particle Duality: Learned de Broglie’s hypothesis (λ = h/p ) and its confirmation through electron diffraction, as demonstrated by Davisson-Germer and G.P. Thompson

• Bragg’s Law Application: Gained proficiency in applying Bragg’s law (2d sin θ = nλ) to analyze electron diffraction patterns from graphite’s crystal lattice.

• Experimental Apparatus: Mastered operating an electron diffraction tube with a 5 keV electron gun, graphite target, and phosphor screen, observing ring patterns.

• Measurement Techniques: Developed skills in measuring diffraction ring diameters

  D at varying voltages (3–5 kV) and using small-angle approximations (sin 2θ ≈ D2L) to calculate interplanar spacings.

• Graphite Lattice Analysis: Understood graphite’s hexagonal lattice structure (unit cell: a = 2.456˚A, c = 6.79˚A) and identified planes responsible for observed diffraction rings.

• Safety Protocols: Learned to handle high-voltage (5 kV) equipment safely, protect the fragile graphite target by limiting beam current (< 0.2 mA), and use plastic calipers to avoid bulb implosion.

• Data Interpretation: Acquired expertise in comparing measured interplanar spacings with theoretical values to validate de Broglie’s wavelength predictions.

Experiment 3: Frank-Hertz

• Energy Quantization Evidence: Learned the historical significance of the Frank-Hertz experiment in confirming atomic energy quantization, as predicted by Bohr’s model.

• Experimental Setup: Gained proficiency in setting up a mercury-vapor tube with a heated cathode, anode, and collector, measuring collector current with a picoammeter.

• Collision Dynamics: Understood elastic and inelastic electron-atom collisions, observing current drops when electron energy matches mercury’s excited state (2537 ˚A photon emission).

• Temperature Control: Developed skills in operating a thermostatic oven to maintain mercury vapor pressure at 150–180°C, avoiding temperatures above 250°C.

• Data Collection: Mastered plotting collector current versus anode voltage, identifying multiple peaks and minima corresponding to successive inelastic collisions.

• Data Collection: Mastered plotting collector current versus anode voltage, identifying multiple peaks and minima corresponding to successive inelastic collisions.

• Safety and Circuit Handling: Acquired expertise in managing high-voltage circuits, shielding collector connections, and preventing plasma discharge by limiting anode voltage.

Experiment 4: Spectroscopy

• Spectroscopy Fundamentals: Learned the principles of analyzing materials via absorption, reflection, or emission spectra, focusing on the emission spectra of low-pressure gases excited by electrical discharge.

• Grating Spectrometer Calibration: Gained proficiency in calibrating a spectrometer using the sodium line spectrum and the grating equation d sin θ = mλ, identifying first-order diffraction lines.

• Emission Spectra Measurement: Developed skills in measuring emission wavelengths of hydrogen (H) and other gases (He, Ne, Hg, or N2), comparing results with tabulated values.

• Rydberg Constant Determination: Acquired expertise in calculating the Rydberg constant R from hydrogen spectral lines for n = 3, 4, 5.

• Molecular Spectra Observation: Understood the continuous rotational-vibrational spectra of molecular gases like N2 due to closely spaced quantum mechanical energy levels.

• Molecular Spectra Observation: Understood the continuous rotational-vibrational spectra of molecular gases like N2 due to closely spaced quantum mechanical energy levels.

• Reference Utilization: Enhanced ability to consult optics textbooks (e.g., Fowles, Jenkins and White, Hecht and Zajec) for theoretical background before experimentation.

Experiment 5: Cosmic Microwave Background

• CMB Fundamentals: Learned the physical properties and origin of the Cosmic Microwave Background (CMB) radiation, formed 370,000 years post-Big Bang during recombination.

• Planck’s Model Application: Understood Planck’s blackbody radiation model and its relevance to CMB energy density as a function of wavenumber and

  temperature.

• Data Fitting with Python: Gained proficiency in using Python packages (e.g., SciPy) to fit experimental CMB data to Planck’s model, optimizing for Planck’s constant with known temperature.

• Temperature Estimation: Developed skills in fitting CMB data with known h to determine the cosmic background temperature, validating theoretical predictions.

• Error Estimation: Learned to estimate standard errors in fitted parameters (h and T) using statistical methods, assessing the reliability of results.

• Scientific Reporting: Enhanced ability to structure a lab report with sections on CMB discovery, properties, Planck’s model, Python tools, data analysis, and conclusions on model validity.

• Data Interpretation: Acquired expertise in analyzing satellite-collected CMB data, linking electromagnetic energy density to temperature and frequency.

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Explore the skills I learned during my Chemistry labs!

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