PML 2023 SURF Projects

Eric Norrgard

eric.norrgard [at] nist.gov (eric.norrgard@
nist.gov )

On campus

Rotational Cooling of a Molecular Beam

Polar molecules can be used as precision quantum sensors of their environment (radiance temperature, pressure, electromagnetic fields, and more). Often this requires a large number of molecules to be in a given quantum state. Student will develop and use a combination of microwave and laser frequencies to “cool” the rotational distribution of a molecular beam. Student will assist in data collection to demonstrate effectiveness of cooling technique, determined by the increased population in the target quantum state.

Ian Spielman

ian.spielman@
nist.gov 

On campus

Disorder potentials for Bose-Einstein condensates

The successful student will use digital mirror devices (DMDs) commonly used in overhead projectors to create a disordered optical pattern. This pattern will illuminate an atomic Bose-Einstein condensate (BEC) creating a random energy landscape for the atoms to move about in.

Zachary H. Levine

zlevine [at] nist.gov (zlevine@
nist.gov )

Remote

Soliton Formation in a Laser Cavity Containing an Rb Vapor Cell: Simulations

Highly stable lasers can interact with the hyperfine-split levels of certain atoms such as Rb. The dielectric response of such systems is highly dispersive and nonlinear. The active media are in an optical cavity formed by optical fibers, leading to well-defined modes in the environment. The project seeks to calculate the response of such systems to both pulses and periodic driving fields. We hope to find stable periodic patterns which correspond to soliton solutions. The methods will be primarily numerical with some analytic work on model systems

Stephen Eckel

stephen.eckel@
nist.gov

On campus

Creating a fully digital proportional-integrator-differentiator servo loop

For the cold atom vacuum standard, we use several analog proportional-integrator-differentiator (PID) circuits for to control laser frequencies, laser intensities, magnetic fields, and temperatures. Not only are our current generation of PIDs based on unreliable analog electronics, they are also missing features, such as sampling and holding the integrator, that would be extremely useful for our experiment. For this project, we would like to build a new, fully digital PID based on a field-programmable gate array (FPGA) or microcontroller with all the complex features we need for our specific experiment. We will most likely build our PID around a Red Pitaya. Once developed, the student will help to deploy the PID on the apparatus to help control our complex laser-cooling apparatus. The student will learn programming and engineering skills, and help to develop an excited new tool that will be used in the lab for years to come.

Thinh Q. Bui

thinh.bui [at] nist.gov (thinh.bui@
nist.gov )

On campus

Electronic instrumentation for magnetic particle imaging (MPI)

In the current Thermal MagIC IMS program, we are developing a novel 3D thermal imaging technology based on magnetic nanoparticles as nanoscale temperature sensors. To achieve fast, high throughput 3D thermal imaging, we rely on state-of-the-art electronics to generate magnetic fields for excitation of nanoparticles and detect their time-dependent response. This requires custom, tailormade analog and digital electronics to operate the homebuilt electromagnets and magnetic sensors. The electromagnets for the excitation field are driven by high-power resonant circuits, and the detection of magnetic nanoparticle response utilizes low-noise amplifiers and filter circuits to maximize signal-to-noise. Experience in circuit design (SPICE), electronic measurements, electronics labwork, and programming for control and data acquisition with LabVIEW, MATLAB, or Python are desired.

Richard Steiner

richard.steiner@
nist.gov 

On campus

Power and Energy instrument calibrations for the US Electric Power Grid

As car chargers and solar panel arrays proliferate, a new DC Power and Energy calibration service is needed to accurately calibrate the instruments used to measure (and charge money for) that power and energy. Accurately determining all the variables in this project means studying and learning the programming details and physics of how electric signal sources and meters work in real conditions. There are several mini-projects involved: 1. Accurately characterize a current transducer (I-to-V converter) to measure up to 200 A of current; 2. Program several instruments to generate up to 200 A and 1000 V; 3. Program two digital multimeters to measure the current and voltage, while keeping accurate time of the integration periods; 4. Learn to use and program power meters or power calibration sources, if available; 5. Calculate the correction factors and uncertainties in the measurements; 6. Create and document a procedure, including an analysis of the hazards involved.

Daniel Barker

daniel.barker [at] nist.gov (daniel.barker@
nist.gov )

On campus

Automated data acquisition and analysis for optomechanical thermometry

In the applied optomechanics lab, we are developing optomechanical primary thermometers, which use laser light to measure the thermal motion of nanoscale mechanical systems to deduce temperature. The current thermometry data acquisition setup uses manufacturer-provided software to control lab instrumentation and requires us to be physically present in the lab to change experimental settings. In this project, we want to develop Python programs to control the apparatus, automate data acquisition, and send SMS alerts when errors occur. The student will also build any electronics necessary for automation and help to create data analysis scripts that interface with the new apparatus control software. During the course of the project, the student will gain scientific programming, optical alignment, and data analysis skills as well as contribute to an aspect of the apparatus that will be used for the foreseeable future.

Arvind Balijepalli

arvind.balijepalli@
nist.gov

On campus

High-Resolution Bioelectronics Metrology

Charge sensitive electronics provide a label-free approach to measure multiple biomarker types such as proteins, nucleic acids and small molecules. This project involves developing instrumentation and data acquisition tools for multiplexed measurements of DNA. The student will develop LabView and Python scripts to interface measurement instrumentation such as lock-in amplifiers and PID controllers with switch matrices to realize multi-channel measurements.

Christina Hacker

christina.hacker [at] nist.gov (christina.hacker@
nist.gov )

On campus

Spectroscopic analysis of low-dimensional interfaces for optoelectronic and magnetoelectronic applications

In this project, the student will leverage the spectroscopic techniques at NIST to study interfaces of low dimensional materials like nanoparticles and monolayers with polymer films. These interfaces are expected to demonstrate interesting optoelectronic and magnetoelectronic behavior that could be leveraged for next generation devices. Duties will include learning and utilizing advanced spectroscopic techniques, building optical systems for sample characterization, and fabricating samples for testing via spin-coating and vapor deposition.

Jason Ryan

jason.ryan@
nist.gov

On campus

Advanced Characterization of Few- and Single Defect Transistors

Atomic-scale defects at the oxide/semiconductor interface of metal-oxide-semiconductor field-effect transistors (MOSFETs) have become increasingly difficult to study as transistors have been scaled down to impossibly small dimensions. In some cases, modern MOSFETs can contain very few, or even just a single defect. Despite their small numbers, these defects remain important to MOSFET function and reliability, and they may have other applications outside of the typical operation of a MOSFET. The goals of this project are to: 1. Experimentally explore the sensitivity limits of the characterization techniques used to study atomic-scale defects in MOSFETs. These techniques include current vs. voltage measurements, charge pumping, gated diode measurements, capacitance vs. voltage measurements, and others. The extension of these techniques to electrically detected magnetic resonance may also be explored. Comparing the relative sensitivities of these methods on standard, well-characterized test structures is not only beneficial to the field of metrology, but also will allow for better communication between NIST’s Magnetic Resonance Spectroscopy project staff and potential collaborators. 2. Experimentally evaluate the utility of the characterized few- and single-defect MOSFETs for alternate purposes such as sensing or probing electron/nuclear spin interactions. Pushing the limits of the techniques above could ultimately lead to the observation of quantized charge transfer and quantized spin transitions. The duties of the intern will include: 1. Reviewing literature on MOSFET interface defect characterization; 2. Characterizing MOSFETs on a wafer probing station with the techniques listed above; 3. Organizing, plotting, and reporting data to the PI and research group.

Joseph Tan

joseph.tan [at] nist.gov (joseph.tan@
nist.gov )

On campus

Experiments with highly charged ions

Highly ionized atoms have certain long-lived states that are potentially interesting candidates for optical atomic clocks and for determination of fundamental constants. Experiments can utilize a compact electron beam ion trap (mini-EBIT) or the NIST superconductive EBIT to facilitate the generation of such exotic charge states.

Isabel Chavez-Baucom

isabel.chavez.
baucom [at] nist.gov

On campus

Laboratory Metrology Proficiency Testing and Training Resource Development

SURF candidate will work directly with their mentor to collaborate with subject matter experts to develop Office of Weights and Measures (OWM) Proficiency Testing (PT) Program quality and statistical analysis tools, program and implement a PT tracking and process management scheme with companion user instructions, improve the PT artifact inventory management process (Access database) that is used by OWM’s national program coordinators and participants to support calibration laboratory Recognition and Accreditation requirements. Candidate will collaborate to develop measurement science training resources, including video scripts and storyboards. Videos may include: PT Quality Manual (NISTIR 7214) and PT Test Policy and Plan (NISTIR 7082) topics, such as statistical equations and Pass/Fail criteria; or laboratory operating procedures and techniques, such as care and handling of state standards (GLP 3), understanding factors affecting weight operations (GMP 10), and standard operating procedures (SOP 8); and/or general “Welcome to Training” topics that support OWM’s IACET accredited Training Program. The candidate will serve on an OWM working group exploring new modes of training service delivery, such as Learning Management Systems and Virtual delivery platforms. This project will be hosted as an in-person (Gaithersburg campus) workplace experience. The researcher will work with a diverse team to research, design, develop, edit, and produce project deliverables. Project development will include independent and collaborative research, defining project, purpose, scope, goals, and timeline. Typical tasks may include reviewing current publications and scientific literature, applying international and national PT statistical methods and techniques, spreadsheet design and validation, handling and organizing PT artifacts, collaborating with state laboratory stakeholders, training video script writing, storyboarding and editing support, reviewing training presentations, identifying appropriate photographic assets, and draft publication review for 508 compliance and content accuracy to meet NIST publication requirements.

David La Mantia

david.lamantia [at] nist.gov (david.lamantia@
nist.gov )

On campus

Compact Blackbody Radiation Atomic Sensors

Electromagnetic radiation sensing is at the core of modern physics. While coherent radiation sensing techniques are quite mature, incoherent radiation sensing has not seen significant recent advancement. A ubiquitous source of incoherent radiation is blackbody radiation (BBR); i.e., radiation emitted by thermal bodies. Characterizing BBR is an appropriate technique to accurately assess the temperature of a distant entity. Rydberg atoms are a cutting-edge tool with enhanced physical properties. Therefore, it is natural they be used in electrometry as radiation sensors. The undergraduate Research Fellow will participate in an experiment dedicated to the use of Rydberg atoms to serve as calibration-free, SI-traceable sensors of thermal radiation, thereby characterizing reference blackbodies and greatly reducing the calibration uncertainty for classical thermal radiation sensors.

Amit Agrawal

amit.agrawal@
nist.gov

On campus

Development of flexible broadband nonlinear metasurfaces with multiresonant plasmonic enhancement

Simultaneous nano-localized enhancement of excitation and emission transitions in nonlinear processes remains a challenge in nanophotonics research but can offer many applications in coherent light conversion, imaging, sensing, quantum optics, and spectroscopy. This project aims to develop flexible nanolaminate plasmonic metasurfaces with broadband multiresonant enhancement of excitation and emission transitions in the second harmonic generation (SHG) and third harmonic generation (THG) processes. In the first stage, the student will employ physical vapor deposition to create flexible nanolaminate plasmonic metasurfaces on nanoimprinted polymer nanopillar arrays based on different plasmonic metal materials, including Ag, Au, Cu, and Al. In the second stage, the student will assist in conducting optical measurements to characterize both linear and nonlinear optical characteristics of the fabricated nanolaminate plasmonic metasurfaces. We envision that Al-based plasmonic metasurfaces can push the nonlinear SHG/THG emission into the UV region, and Ag-based plasmonic metasurfaces can achieve the broadest nonlinear SHG/THG emissions over the entire visible to near-infrared range.

Csilla Szabo-Foster

csilla.szabo-foster [at] nist.gov ( )

Remote or on campus

Electric field modelling for medical physics application

Radiation therapy with small, encapsulated implantable sources (brachytherapy) is a powerful tool in the treatment of various kinds of cancer. The National Institute of Standards and Technology (NIST) maintains the U.S. primary standard for radioactive source strength (air-kerma-strength) for low dose rate photon emitting brachytherapy sources. The device to provide these measurements is the Wide-Angle Free-Air Chamber (WAFAC). The WAFAC has a front membrane electrode with a cylindrical side electrode raised to high voltage potential to guide electrons to the grounded back electrode when ionizing radiation enters the chamber. The scope of this project is to create a model of the WAFAC in COMSOL Multiphysics software and simulate the electric field of the ion chamber under various conditions. This research will help us to understand the influence of systematic effects on brachytherapy source strength measurements and with that potentially improve the understanding of sources of measurement uncertainty.

Joseph Robertson

joseph.robertson@
nist.gov

On campus

Plasmonic nanopores through DNA nanotechnology

The student will develop a generalized nanopore sensor platform that will allow for rapid control over the local temperature gradients at various length scales at a nanopore resistive pulse biosensor. Plasmonic nano-structures will be fabricated through DNA nanotechnology (origami), which will create super-assemblies of pore forming proteins and plasmonic nanoparticles and these will be used as an optically modulated single-molecule sensor. The student will design LSPR-DNA origami structures to organize and place particles with precision on the 1 nm to 100 nm length range and test the feasibility of creating structures with mixed particles (i.e., combining Au clusters with diamond nanoparticles) to create sensors that provide both optical and ionic measurement of local temperature. These structures and measurement protocols will also advance fundamental biophysical measurements, such as that found in transport of peptides and proteins across membranes.

Aaron Goldfain

aaron.goldfain [at] nist.gov (aaron.goldfain@
nist.gov )

On campus

Directional reflectance measurements from the UV to IR

NIST is creating an open access database of the optical directional reflectance of materials. How materials reflect light in different directions is important to a variety of applications, such as the disinfection of public spaces using UV light and interpreting satellite-based remote sensing images of the Earth. We will use a new commercial instrument to measure the directional reflectance, specifically the bidirectional reflectance distribution function (BRDF), of a wide range of materials across the wavelength range of 200 nm to 2400 nm. We will thoroughly characterize the new commercial instrument by validating it against other NIST instruments and will improve its performance as necessary. A key part of this validation will be formulating an uncertainty budget. One of the main challenges anticipated with this project will be ensuring the results are accurate when measuring materials with varied and unusual optical properties. There will also be opportunities to explore new methods to visualize and share BRDF data, as our goal is to eventually build an interactive, online data viewer where users can explore and download BRDF data.

Joe Rice

joe.rice@
nist.gov

On campus

Stability of Photodiodes in Space

The student will mine existing data from three satellite missions from NIST collaborators at the University of Colorado Laboratory and Atmospheric Space Physics (LASP). These three satellites used a variety of photodiodes and thermal detectors to measure solar flux across the near ultraviolet, visible, and near-infrared as their primary missions. As a secondary bye-product that has not yet been analyzed, data exists that can be analyzed for spectral response stability. The student will work with collaborators at LASP to obtain the data, understand the data formats, and perform analysis to extract information about how much silicon and InGaAs photodiodes degrade while exposed to the harsh radiation environment of space. This will inform future satellite missions trying to select photodiodes for accurate measurements from space.

Jared Wahlstrand

jared.wahlstrand [at] nist.gov (jared.wahlstrand@
nist.gov )

On campus

Time-resolved spectroscopy of excitons and exciton-polaritons in organic crystals

Organic semiconductors offer a number of potential advantages over conventional semiconductors, including low-cost processing and the ability to tailor materials by modifying molecular structure. For opto-electronic applications, they have particularly interesting and rich properties, including tightly bound excitons (bound electron-hole pairs) that interact strongly with light and remain bound at room temperature, with spin dynamics that depend sensitively on material properties and can be modified by applying a magnetic field. Recently, it was shown using time-resolved fluorescence measurements that organic crystals placed on 2D plasmonic nanoparticle arrays display modified exciton dynamics due to the formation of exciton-polaritons, hybrid modes that result from strong light-matter coupling. This phenomenon may enable new applications of these materials, but before it can be applied in a commercial setting, more fundamental research is needed. The student will perform experiments using a broadband subpicosecond pump-probe setup and a streak camera to investigate exciton and exciton-polariton dynamics in organic crystals. The project will involve a combination of hands-on experimental work and data analysis.

Greg Cooksey

Gregory.cooksey@
nist.gov

On campus

microfluidic cytometry

This project supports the development of a microfluidic cytometer that repeats measurements of single objects in flow. These measurements enable estimation of per-object uncertainty, something conventional cytometers cannot do, which facilitates optimization of device performance and leads to better classification of sample composition. The student will learn how to make microfluidic devices with integrated optical waveguides, to interface the chips with flow systems, light sources and detectors, and to collect and analyze data. The student will explore measurement of object size and shape and work on metrics to improve cell counting and classification. The student will receive appropriate safety training in addition to hands-on training regarding the other specialized equipment in the NIST laboratory.

Emily Bittle, Katelyn Goetz

emily.bittle [at] nist.gov (emily.bittle@
nist.gov );
Katelyn.goetz@
nist.gov 

On campus

Towards Rapid Optimization of Solution-processed Organic Thin-film Transistors

Organic semiconductors are processable from solution, making them suitable for low-temperature fabrication processes on flexible substrates. This is beneficial because it enables previously impossible electronic devices. Unfortunately, solution processing is complex and depends on numerous interactions between the semiconductor solute, solvent, and substrate, making the window of optimal processing difficult and time-consuming to understand. Only a select few, high-performance semiconductors undergo optimization at a years-long, cross-laboratory pace. This both reduces commercialization potential and complicates scientific metrology studies where a lower-performance semiconductor may be interesting. For this project, the SURF student will develop strategies to reduce the time taken to optimize the solution-processing parameter space. They will fabricate organic field-effect transistors by the blade-coating technique, image them and measure their electrical characteristics, and finally, develop a MATLAB or Python-driven toolkit to rapidly correlate structure-function properties for a large set of devices. This work will assist scientists in the fabrication of “ideal” devices for both commercial and scientific purposes. Tasks: 1. Fabricate, measure, and image organic field-effect transistors; 2. Write code to rapidly identify and catalogue features of interest; 3. Correlate optimal electrical characteristics with image features and fabrication procedure; 4. Use results to refine fabrication process

Ronald E. Tosh

ronald.tosh [at] nist.gov (ronald.tosh@
nist.gov )

Remote or on campus

Ultrasonic CT for radiation dosimetry

Cancer therapy with external-beam radiation seeks to destroy malignancies while minimizing damage to surrounding healthy tissue. This often entails elaborate mechanisms for shaping radiation beams spatially and temporally to optimize conformality of dose delivery to irregular tumor volumes. Absolute dosimetry of such highly nonuniform dose distributions is not possible with current technology, but we are working on dose-imaging techniques that would make this achievable. One such technique pioneered at NIST uses an array of transducers for imaging temperature changes within an irradiated phantom. Computational modeling of the thermal response of the array and acquisition and processing of temperature profiles is necessary for interpreting experimental data and design improvements. This project would seek to advance preliminary work we have completed in finite-element modeling of heat transfer in irradiated phantoms and simulation of image-data acquisition and tomographic reconstruction of temperature distributions, ultimately to involve a hybrid computational platform combining CPUs and a GPU.

Brittany Broder; Denis Bergeron

brittany.broder@
nist.gov ;
denis.bergeron [at] nist.gov (denis.bergeron@
nist.gov )

On campus

Source Measurements and Simulation of Dose Calibrator

A new generation of radiotherapeutic agents are being developed in the medical community to target disease and treatments more directly. The efficacy of these treatments is often determined using quantitative imaging to assess how much of the radiopharmaceutical accumulates in a tissue of interest compared to the initial administered activity. An accurate, reliable measurement of the activity is necessary for precision imaging and dosimetry for therapy treatments. Such measurements are usually made with radionuclide dose calibrators, a common utility in nuclear medicine to determine the initial activity administered to the patient. NIST is responsible for making sure dose calibrator measurements can be made with traceability to a common National standard, making dose calibrators an important tool in disseminating activity standards. Modelling dose calibrators allows us to predict the response for new nuclides and validate experimental data. In this project, the student will use a model of a commercial dose calibrator to simulate the response of various nuclides using TOPAS, a Geant4-based, Monte Carlo simulation program. The student will validate their simulations by comparing the results to published response curves and measurements they obtain in the lab. The student may also use this model to investigate measurement errors that can arise when sources are measured under common clinical conditions.

Susana Deustua

susana.deustua@
nist.gov

On campus

NIST Stars: Absolute Flux Calibration of Stars for Astronomy

The objective is to provide visible and near infrared stellar spectral energy distributions of standard stars with sub-percent uncertainty that are SI-traceable for use by the astronomical research community. Some of the research areas supported by these improved flux standards are dark energy experiments, the growing area of exoplanet research, and stellar astrophysics. In collaboration with the European Southern Observatory in Chile, NIST is building a research station on Cerro Paranal, whose instruments include small telescopes, and instruments for measuring atmospheric properties. We are also interested in research using LIDAR, spectroradiometry, and other methods to improve the determination of the atmospheric corrections. In preparation for deploying our telescope system in Chile, we shall be characterizing the instruments, automating telescope operation, and testing these in the lab and on the sky.

Mark Stiles, Nitin Prasad

nitin.prasad [at] nist.gov (nitin.prasad@
nist.gov );
mark.stiles@
nist.gov

Remote

Training embedded inference engines to be robust against device variations

Efficient computation on edge-computing platforms such as autonomous vehicles requires the use of compressed neural network models with low precision parameters. Binary neural networks, in which network parameters take one of only two values, are extreme versions of such compressed models. These networks can be realized in mixed signal computing platforms containing arrays of devices with bistable conductance values. However, implementations of such bistable devices are prone to device-to-device variations, which degrade performance. The goal of the project is to create offline training algorithms that account for and compensate for such device-to-device variations during the offline training process. The resulting offline-trained solutions should exhibit optimized accuracies when implemented on physical networks with actual device variations.

Maritoni Litorja

litorja [at] nist.gov (litorja@
nist.gov )

On campus

DC Power and Energy Calibrations to Verify Electric Vehicle Supply Equipment Meters

The power and energy dispensed by charging equipment to an electric vehicle has to be verified using secondary field meters. These meters in turn, must be calibrated to be traceable to the SI. This project has several parts: 1) work with the Office of Weights and Measures to determine the calibration needs of the EVSE community and 2) work with another student (advisee of Dr. Richard Steiner) to develop the basic laboratory measurements necessary for a NIST calibration service to disseminate SI to meters used by regulators. 3) Depending on the time available, test commercial charging equipment using a commercial field meter.

Yaw Obeng

yaw.obeng@
nist.gov

On campus

ANALYTICAL Simulations of Electromagnetic Test Structures to Investigate and Partition Microwave Signal Losses In emerging barrier materials for Cu Interconnects

Higher-speed signal transmission is increasingly required to handle massive data in electronic systems. So, signal transmission loss of copper wiring interconnects is critical. The total signal loss can be divided into dielectric loss and conductor loss based on electromagnetic theory. In particular, the scattering loss due to skin effects, and the copper-barrier interface will be quantitatively examined in detail. The elative usefulness of the emerging copper barriers materials, and their interfaces to copper, will be examined though analytical simulations. Specifically, efforts will be made to understand signal loss partitioning, viz.: 1. Losses in the metal (Cu): Skin Effect, metal surface roughness; 2. Losses in the dielectric around metal line; 3. Losses in the metal-dielectric / corrosion film interface: voids, corrosions; 4. Losses into the Si substrate; 5. Where else? Starting from existing base COMSOL codes, the SURF student will evaluate the impact of some newly identified Cu-barrier candidate materials on high speed signal loss. The exiting codes may be optimized based on new physical/ chemical insights, as well as to improve accuracy and computation efficiency.

Jason Underwood

jason.underwood [at] nist.gov (jason.underwood@
nist.gov )

On campus

Quantum waveform metrology

Over the last several decades, quantum voltage standards based on the Josephson effect have revolutionized dc electrical metrology. More recently, the development of the Josephson Arbitrary Waveform Synthesizer (JAWS) promises to improve ac electrical metrology and may eventually supersede artifact standards. Students will contribute to research efforts on quantum-based arbitrary waveform synthesis and control. Concepts covered include instrument control, digital signal processing, superconducting electronics, and formal uncertainty evaluation.