Student Talks


Science Ctr 304          Detecting and Measuring Land Subsidence in Houston-Galveston, Texas Using Interferometric Synthetic                                                                                                        Aperture Radar (InSAR) and Global Positioning System Data, 2012-2016.

                                                                                                  Ayanna Reed, Dr. Scott Baker

Several cities in the Houston-Galveston (HG) region in Texas have subsided up to 13 feet over several decades due to natural and anthropogenic processes [Yu et al. 2014]. Land subsidence, a gradual sinking of the Earth’s surface, is an often human-induced hazard and a major environmental problem expedited by activities such as mining, oil and gas extraction, urbanization and excessive groundwater pumping. We are able to detect and measure subsidence in HG using interferometric synthetic aperture radar (InSAR) and global positioning systems (GPS). Qu et al. [2015] used ERS, Envisat, and ALOS-1 to characterize subsidence in HG from 1995 to 2011, but a five-year gap in InSAR measurements exists due to a lack of freely available SAR data. We build upon the previous study by comparing subsidence patterns detected by Sentinel-1 data starting in July 2015. We used GMT5SAR to generate a stack of interferograms with perpendicular baselines less than 100 meters and temporal baselines less than 100 days to minimize temporal and spatial decorrelation. We applied the short baseline subset (SBAS) time series processing using GIAnT and compared our results with GPS measurements. The implications of this work will strengthen land subsidence monitoring systems in HG and broadly aid in the development of effective water resource management policies and strategies.

Science Ctr 105                                                                Designing The TolTEC Camera. 

                                                                                              Alexandra Burkott, Grant Wilson

Ground based millimeter wavelength telescopes offer astronomers the ability to observe the dust obscured universe - elucidating fundamental questions about the universe that we live in.  With the addition of the TolTEC camera to the suite of instruments on the Large Millimeter Telescope in 2018, astronomers will be able to map deeper, larger areas of the sky faster and to a higher resolution than ever before.  TolTEC observes in three bands simultaneously and increases the mapping efficiency of the LMT by two orders of magnitude.  The instrument also features polarization-sensitive detectors and will be used to map the effect of magnetic fields in star-forming regions. TolTEC employs kinetic inductive detectors - a superconducting detector technology - cooled to 0.1K. Here we detail the design of the cryogenic system of TolTEC and it’s optimization.

Science Ctr 309A                                                       Elastic Buckling of Rigid Bio-Polymers.

                                                                  Margaret Morris, Feodor Hilitski, Walter Schwenger, Zvonimir Dogic (PI)

It has recently been found that some rigid-biopolymers, particularly microtubules, do not bend like Eulerian rigid rods, in that they become softer the further they are bent. Using optical tweezers, we measured the force required to buckle straight bacterial flagella and found that they do bend as Eulerian rods. This allows us to use our measurements to determine the persistence length of the flagella, which we also determine independently by observing the filaments` thermal fluctuations.

Science Ctr 110                                 Electrical Transport in a Few-Layer High-Temperature Superconductor.

                                           Margaret Panetta, Frank Zhao, N. Poccia, R. Zhong, G. Gu, K. Watanabe, T. Taniguchi, Philip Kim (supervisor)

When thinned to a few atomic layers, superconductors behave differently than they do in their bulkier forms. While electrons in thin film superconductors still form Cooper pairs that normally condense into a superconducting state, when a magnetic field is applied to these materials, their superconductivity is destroyed even at the lowest experimentally achievable temperatures. We investigate electronic transport in thin films of Bi2Sr2CaCu2O8+x (BSCCO) a copper-oxide high-temperature superconductor. We measure the resistance of thin samples down to the millikelvin range under an applied magnetic field, seeking to characterize the behavior of the material at one thousandth of the BSCCO superconducting transition temperature of 85K. To do this, we employ a novel stencil-mask technique to pattern electrical contacts to samples while avoiding surface degradation during lithography. We observe behavior consistent with that of bulk BSCCO in samples thicker than nine copper oxide planes: resistance decreases linearly with temperature, before displaying a transition to a superconducting state at the conventional transition temperature. We observe anomalies in the resistance of thin samples at low temperature: the superconducting transition is slightly broadened, and a finite resistance reappears at temperatures below the transition temperature before again decreasing. 

Science Ctr 216                   A Micromegas-based Directional Dark Matter Detector for Use with Negative Ion Gases.

                                                                                                                 Catherine Nicoloff, James Battat

Directional dark matter detectors seek to measure the direction of WIMP-induced nuclear recoils. The angular distribution of these recoils provides a unique signature that is not mimicked by any known background population. Low-pressure gas time projection chambers (TPCs) have a long and successful history in directional dark matter searches. The benefit of the low-pressure gas target is that nuclear recoils from dark matter extend long enough to be reliably reconstructed. For the last decade, the DRIFT collaboration has employed a MWPC-based negative-ion TPC for directional dark matter detection. DRIFT recently published the leading limit from a directional detector on the spin-dependent WIMP-proton interaction (1.1 pb at a WIMP mass of 100 GeV/c^2). Although the effective spatial granularity along the drift direction is 60 um, the MWPC wire spacing of 2 mm limits DRIFT`s track reconstruction. DRIFT is now exploring TPC readouts that offer higher spatial resolution. Here, we report on one such effort that uses a Micromegas for gas amplification with orthogonal strips for charge signal readout. The detector can be used with both electron drift and negative ion gases. We will describe the detector design and present preliminary commissioning data taken in a surface laboratory.

Science Ctr B10                             Counts of Galaxy Clusters: abundance matching across wavelengths                                                                                                        

                                                                                                    Xinyi Chen, August E. Evrard, Arya Farahi

Galaxy clusters, the most massive gravitationally bound structures in the universe, are a powerful probe to study cosmology. With calibration by simulations, cluster counts can be calculated from a mass function, the space density of halos as a function of mass and redshift. We extend the approximate mass function treatment in Evrard et al. (2014) to compute the mass function of halos in the redshift range 0<z<2.5, for WMAP7 and Planck15 cosmologies. We compare our theoretical model with the SPT and Planck SZ cluster catalogs as well as the redMaPPer optically selected SDSS DR8 catalog, finding interesting discrepancies.


Science Ctr 304            Comparison of Satellite and Ground-Based Observations of Solar Energetic Particle Event Onsets.

                                                                                              Jing He, Juan Rodriguez  

Solar energetic particles (SEPs) propagating to Earth cause airline communication blackouts, radiation hazards for astronauts and airline passengers, and upsets in as well as degradation of spacecraft electronics. The NOAA Space Weather Prediction Center uses observations from the Geostationary Operational Environmental Satellites (GOES) to monitor SEPs. This satellite-based system for monitoring SEP events is complemented by a network of ground-based neutron monitors (NMs). Detections of SEPs by NMs, also called ground level enhancements (GLEs), are particularly important for mitigating radiation dosage to airline passengers and crew during a SEP event.  A previous study by Kuwabara et al. (Space Weather, v. 4, S10001, 2006) concluded that a NM network could detect GLE onsets ~10-30 minutes earlier than GOES. However, their study did not account for differences in the instruments, the time resolution of the data, and the alert protocols. Using newly-available high-resolution data from GOES 8-12 and NMs, we analyzed 16 GLEs from 1997-2006 and conducted a more ‘apples-to-apples’ comparison of these two systems’ relative GLE detection times using 1-minute-cadence data. We reproduced Kuwabara et al.’s results for NM onsets using their real-time onset-detection technique (which involves a moving trailing average), then applied the same technique to the GOES observations, tuned to the different background noise levels such that false alerts are minimized. We compared the NM and GOES onset times and discovered that they did not differ as drastically as Kuwabara et al. claimed. Moreover, there was no significant local time dependence of the GOES onset times. The median difference between GOES and NM onsets was 1 minute (GOES lagging NM), with the 80th percentile of the differences (GOES onset – NM onset) being 3 minutes.

Science Ctr 105             AGN-halo Mass Assembly Connection in Galaxy Clusters: Investigation Using the Splashback Radius.

                                                                                                           Melissa McIntosh, Surhud More, John Silverman

The splashback radius (also known as the last density caustic or the second turnaround radius) is a sharp dark matter halo edge that corresponds to the location of the first orbital apocenter of satellite galaxies after their infall. This definition of a halo boundary is more physical compared to the traditional definitions of halo boundaries which tend to be quite arbitrary. The splashback radius responds to the mass assembly history of clusters. For dark matter halos of the same mass, a large mass accretion rate results in a smaller splashback radius, since its deeper halo potential well has a closer apocenter. Using two cluster samples which had the same mass, but different splashback radii, we set out to check if the incidences of active galactic nuclei (AGN) in the member galaxies of these clusters are affected by their mass assembly history. Using SDSS spectroscopic data, we determined metallicity of galaxies and constructed a BPT diagram to classify each galaxy member in each cluster (Seyfert, Liner, Composite, etc.) and determined if an AGN was likely to be present. We compared the samples and determined that the rapidly assembling sample did have a larger AGN presence. 

Science Ctr 309A                              Improving Alternating Magnetic Field Setups for Biomedical Applications.

                                                                                                    Christina Howe, Michael G. Christiansen, Polina Anikeeva

Biomedical applications of magnetic nanoparticles (MNPs) include cancer hyperthermia, drug release, and minimally-invasive cellular stimulation. Alternating magnetic fields (AMFs) cause MNPs to dissipate heat locally due to hysteresis losses while leaving surrounding tissue unaffected. In addition to bulk heating, recent experimental evidence has suggested that nanoscale heating of MNPs is orders of magnitude greater than predicted by macroscopic heat transport. Even the physical process of heating is a topic of active research. Linear response theory, the predominant physical model used to describe MNP heating in AMFs, is not sufficiently general to explain experimental results. New models for describing hysteresis are currently being developed and tested. The experimental setups typically used to produce AMFs with suitable field amplitudes and frequency can be prohibitively expensive and present a barrier to research. This talk will present simple, cost-effective, and robust alternatives to typical AMF setups for multiple experimental scales. For small working volumes (1 cc), the use of soft ferromagnetic cores to focus the flux into a gap is an effective strategy; for larger working volumes (1000 cc), poor thermal conductivity and power dissipation that scales with volume render that strategy ineffective. Surprisingly, it can be shown instead that low loss tank circuits with limited inductance generating more than 1 kA are more effective. These principles are important because determining the most feasible way to scale AMF setups to human-scale is the only way that applications of MNPs will ever leave the laboratory and become clinically relevant.

Science Ctr 110                                      Surface Raman Studies of Reduced Strontium Barium Niobate.

                                                                                                                    Hope Whitelock, Jean Toulouse

The vibrational spectra of SrxBa1−xNb2O6−δ (SBN, x = 0.61) are studied on the surface of single crystals for δ = 0 (unreduced) and δ > 0 (reduced) using Raman confocal microscopy. The surface spectra are compared with the bulk spectra measured using conventional Raman spectroscopy. Differences between bulk and surface measurements based on beam geometry will be discussed. Supported by NSF grant PHY-1359195.

Science Ctr 216                                        Statistical Analysis of Quasar Light Curves from Pan-STARRS1.

                                                                                                            Betsy Hernandez, Tingting Liu, Suvi Gezari

We present a statistical analysis of variable quasars in the Pan-STARRS1 Medium Deep Survey (PS1 MDS).  PS1 MDS obtained multi-epoch images of 10 fields, each 8 square degrees in size, over 4 years, starting in May 2010. The MDS fields were observed in 5 filters (gp1, rp1, ip1, zp1, and yp1) during their season of visibility, with a typical cadence per filter of 3 days.  We extracted the light curves of 670 color-selected quasars in the PS1 MDS using Point Spread Function photometry from the Image Processing Pipeline data products. From the quasar sample, we selected 104 quasars whose variability was at least 2 standard deviations higher than the non-variable reference star sample. We performed a statistical analysis of the light curves of the selected quasars in the g,r,i and z bands using a maximum likelihood method to find the best-fit Damped Random Walk parameters (sigma and tau – also incorporating the Zoghbi et al. 2013 method for uneven sampling). The resulting distributions for sigma and tau were similar to those found in previous studies of quasars.

Science Ctr B10        Impact of the Electron Neutrino Disappearance on the Sterile Neutrino Search in the SBN Experiment.

                                                                                      Maria Prado, Professor David Schmitz, Professor David Tucker-Smith

The Short-Baseline Neutrino (SBN) experiment located at Fermilab is looking for sterile neutrinos by searching primarily for νμ → νe oscillations. The experiment consists of a beam of 99.5% muon neutrinos and 0.5% electron neutrinos aimed at three liquid argon time projection chamber (LArTPC) detectors at different baselines: SBND (near detector), MicroBooNE (intermediate detector), and ICARUS-T600 (far detector). Intrinsic electron neutrinos from the beam could oscillate to a different flavor, canceling some of the νμ → νe signal. My research studies the effects of incorporating νe disappearance into the SBN analysis. This is done by recreating the electron neutrino interaction event distribution and the electron neutrino signal sensitivity surface where sin2(2θee) does not equal zero. These components are still in the process of being completed.


Science Ctr 304   Evaluation of Strontium Iodide doped with Europium coupled with Silicon Photomultipliers for 2-D SPECT Imaging.

                                                                 LaNell Williams, Michael Groza, Jarrhett Butler, Emmanuel Rowe, Todd Peterson and Arnold Burger

The detection of gamma rays for nuclear imaging has become increasingly important in designing non-invasive imaging tools for biological research and modeling. Although imaging techniques such as computed tomography (CT) and Positron Emission Tomography (PET) have been previously used, and improved spatial resolution and sensitivity continue to be an issue. Thus, improvements in these detection devices are needed to create better images for more accurate modeling in research [Cressey, 2011]. Scintillators such as Cesium Iodide (CsI), and Sodium Iodide (NaI) have been used for many imaging techniques for their ease of growth, energy resolution, and overall effectiveness as a gamma ray detectors. In more recent studies, Strontium Iodide doped with Europium (SrI2(Eu2+)has shown to be a promising scintillator compared to NaI and CsI. Because of’s SrI2(Eu2+) improved energy resolution (~2.7%), fast decay time (~1.2 µs) and light yield (110,000 photons/MeV), it is an ideal replacement for technologies that have used previously been made with NaI and CsI. [Cherepy, 2008]. In addition,  SrI2(Eu2+)also has an emission centered around 420 nm making it an ideal scintillator to be used with silicon photomultipliers that provide lower energy consumption than the standard photomultiplier tube. The improved energy resolution of  SrI2(Eu2+)in a gamma camera will result in an promising detector for nuclear imaging.

Science Ctr 105                                The Co-Evolution of Post-Merger Galaxies and Dust-Reddened Quasars.

                                                                                                          Milena Crnogorcevic, Professor Eilat Glikman

This project utilizes data obtained from the OSIRIS integral field spectrograph combined with Laser Guide-Star Adaptive Optics (LGS) to better understand the evolution of moderately dust-reddened quasars as well as their hosting galaxies. The quasars considered are centered in galaxies with high degree of merger activity, and thus we expect to see intense star-formation regions. The high spatial resolution of OSIRIS+LGS allows us to analyze the quasar contribution separately from that of star-formation regions. In turn, this gives us more information about the host galaxy’s activity. The goal is to characterize the evolutionary stage of the host galaxy by extracting information about the degree of star formation and the kinematics for five different targets.

Science Ctr 309A                    Simulation of Excitations in Shell Bose-Einstein Condensates at Finite Temperature.

                                                                                                                   Shuyao Gu, Courtney Lannert

Shell Bose-Einstein Condensates, in the shape of hollow spheres, can undergo a transition from solid sphere condensates to two-dimensional thin closed surface ones in an appropriately-designed trap. Shell condensates pave the way for studying the dynamics of two-dimensional condensates by showing how the oscillation modes change as shell thickness decreases. While previous research has examined the oscillation modes of shell condensates at zero temperature, we extend the scope of the investigation to finite temperature where the system is physically realizable. We use Dissipative Gross-Pitaevskii Equation to describe the behavior of the system and present an algorithm to simulate the damped oscillation of the condensate after initial excitation. The algorithm is tested by reproducing known collective modes of solid sphere condensates. We use this algorithm and study the dynamical behavior of collective modes of shell condensates.

Science Ctr 110                                          Non-Homogenous Flow Behaviors in Dense Emulsions.

                                                                                          Gabrielle Roberts, Vishwas V Vasisht, Emanuela Del Gado

Straining dense emulsions at a constant rate gives rise to non-uniform flow. In this work, we show using computer simulations that the phenomenon may persist well beyond when the shear stress reaches a constant value and the system settles into an apparent steady state. We find that there is indeed a slower evolution of the inter-particle forces that can be detected by pressure.

Science Ctr 216                              Quasiparticles in Flatland: Symmetry, Topological Phases, and Anyons.

                                                                                                        Carolyn Zhang, Dr. Meng Cheng (Yale)

In elementary school, we learn that matter comes in 3 phases: solid, liquid, and gas.  Later on in our studies, we learn that phases of matter can be classified by Landau's theory of symmetry-breaking: magnets break time reversal symmetry and crystals break translation symmetry.  The late 1980s, discovery of orders beyond symmetry breaking introduced the notion of topological phases of matter.  Non-trivial topological phases lead to boundary excitations that can take on fractional quantum numbers: an electron can split into 1/3 charges, or a chargeon and a spinon.  These fractional excitations, called anyons, allow braiding of quasiparticles, the crux of fault-tolerant topological quantum computation.  Here we study a momentum polarization method to extract characteristics of such anyons.  We first benchmark the method with known results of the 2D p+ip topological superconductor.  Next, we develop a way to apply it to time-reversal invariant 3D topological superfluid 3He-B, which combines symmetry with inherent topological order as a symmetry enriched topological phase.

Science Ctr B10                         Design of a Novel Flexible Sensor Based on Human Motion Measurement.

                                                                                Min Huang, Qiuping Sheng, Lele Ju, Bo Jing, Aiping Liu (supervisor)

Our research focus on making composite nanomaterial (such like graphene, copper nanowires), and compositing them with flexible high polymer material which we use PDMS to manufacture multiple flexible sensor. Utilizing the good force sensitive characteristic of graphene, the nice malleability and electro conductivity of copper nanowires can improve the sensitive and durability of flexible sensor. What’s more, it has ability to consider both force sensitive under large deformation and small deformation. By fitting with human body, it has good use of monitoring the signal of large deformation (such like crooking elbow, making a fist, curling fingers). Meanwhile, the sensor can export the waveform of tinny signal in time (such like radial artery pulse and apex beat graph). Some research has shown that the signal of pulse can detect inchoate CVD (cardiovascular disease ). For example, the young patient who get coronary heart disease has some vasculopathy which only reflects on some symptoms like enhancement of radial artery coefficient without enhancement of periphery systolic pressure and pulse pressure. And this one can be used as a useful indicator of early coronary artery disease in young adults and as a new indicator of vascular aging. The flexible sensor attached to a specific limb position, through the hardware circuit and SCM system at the system signal, with the LCD display technology, can achieve real-time monitoring of body movement and signal output. The project provides experimental reference for the development and development of new force-sensitive materials and strain sensors, and real-time monitoring of human health physiological indexes such as pulse, heartbeat and muscle group vibration through flexible strain sensor, and makes timely feedback to human health data. The development of intelligent physiological monitoring equipment provides a new way of thinking and helps to prevent and diagnose the disease early.

Science Ctr 109                            A Million Years Young: Determining the Age of Young Brown Dwarfs.

                                                    Victoria DiTomasso, Ellie Schwab, Emily L. Rice, Adric R. Riedel, Kelle L. Cruz, Jacqueline K. Faherty

Brown dwarfs are substellar astronomical objects that form like stars, but that are not massive enough to fuse hydrogen the way stars do. Brown dwarfs continuously cool, fade, and shrink over billions of years, but maintain the same mass. Changes in radius and temperature affect the brown dwarf`s spectrum, which we can then analyze to determine its age. In order to constrain the ages of 11 potentially young, nearby brown dwarfs, we have reduced their high-resolution near-infrared (1.1-1.4μm) spectra collected using the Keck II telescope in Hawaii. Using this data, we calculated their radial velocities and combined those values with previously calculated parallax distances and proper motions to determine their likelihood of membership in nearby young moving groups, successfully placing three of them. We also compared spectra from our 11 brown dwarfs to spectra of established young and field brown dwarfs in order to evaluate the consistency of spectral indicators of youth across spectral type, age, resolution, and wavelength regime.


Science Ctr 304                                 Development of the PROSPECT Source Calibration System.

                                                                                                         Arina Bykadorova, Karsten Heeger

PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, is an antineutrino experiment operated at Oak Ridge National Laboratory’s High Flux Isotope Reactor (HFIR). PROSPECT will search for short-baseline neutrino oscillations and make a precision measurement of the antineutrino energy spectrum emitted from the highly-enriched 235U core. These measurements will address anomalies found in reactor experiments: a ~6% flux deficit relative to reactor models, which could be an indication of eV-scale “sterile” neutrinos; and a discrepancy between the predicted and measured antineutrino spectrum. PROSPECT is a segmented liquid scintillator detector, read out with photomultiplier tubes. Energy response and position reconstruction are calibrated using radioactive gamma and neutron sources. We have developed a retractable source deployment system that allows the placement of sources along the length of the detector segments. We will present the design of the PROSPECT source calibration system and results from its deployment in the two-segment prototype, PROSPECT-50.

Science Ctr 105                                Primordial Black Holes from First Principles- An Overview.

                                                             Casey Lam, Alan Guth, Jolyon Bloomfield, Zander Moss, Megan Russell, Stephen Face

Given a power spectrum from inflation, our goal is to calculate, from first principles, the number density and mass spectrum of primordial black holes that form in the early universe. Previously, these have been calculated using the Press- Schechter formalism and some demonstrably dubious rules of thumb regarding predictions of black hole collapse. Instead, we use Monte Carlo integration methods to sample field configurations from a power spectrum combined with numerical relativity simulations to obtain a more accurate picture of primordial black hole formation. We demonstrate how this can be applied for both Gaussian perturbations and the more interesting (for primordial black holes) theory of hybrid inflation. One of the tools that we employ is a variant of the BBKS formalism for computing the statistics of density peaks in the early universe. We discuss the issue of overcounting due to subpeaks that can arise from this approach (the “cloud-in-cloud” problem).

Science Ctr 309A                     Probing High-Temperature Superconductivity with Extreme Pressures.

                                                   Grace Zhang, Patricia Alireza, Sofia Taylor-Coronel, Mate Hartstein, Yu-Te Hsu, Suchitra Sebastian

Superconductors carry electrical currents with zero resistance, capable of transferring power without energy loss, expelling magnetic fields to levitate trains, and producing interference effects in quantum circuits. Unlike low-temperature superconductivity, which occurs in conducting parent metals, high-temperature superconductivity is born out of ceramic insulators – cuprates, typically sheets of copper oxide sandwiched between charge reservoirs. These materials exhibit a plethora of intriguing quantum orders; in particular, the copper oxide layers behave like an electronic traffic jam under normal conditions but paradoxically superconduct upon donations of extra charge carriers from the charge reservoirs. In this work, we study the effects of pressure on these charge carriers, in context of these cuprates’ phase diagrams, which map out the boundaries at which these different quantum orders appear and vanish under varying conditions of the material itself and its environment. We demonstrate high pressure as a tool for accessing and controllably exploring previously uncharted territories of the cuprate phase diagram and introduce techniques for investigating their electronic structure under these extreme conditions.

Science Ctr 110                                                           Bridge the Gap Initiative.

                                                                            Rachel Maizel, Joe Meese, Madison Wyatt, James Adam Damon

Bridge the Gap Initiative (BGI) is a program originating from Rensselaer Polytechnic Institute that will provide stability, opportunity, and mentorship to inner-city students that do not have the availability to do so themselves. Ultimately BGI will offer assistance across the nation to minimize the achievement gap in STEM in America.

Science Ctr 216                                Space Oddities: The Search For Ephemeral Coronal Holes. 

                                                                             Rachel O’Connor, W. Dean Pesnell, Michael Kirk, Nishu Karna

Ephemeral coronal holes are short-lived, volatile counterparts to equatorial coronal holes. Very little is known about their characteristics and behavior aside from their definition: open, unipolar magnetic field lines resulting in darkened regions of the corona. The first exemplar of this phenomenon was observed by NASA’s Solar Dynamics Observatory (SDO) on October 26, 2010, which spurred our search for other occurrences in order to understand the frequency and evolution of these phenomena. To accomplish this, we visually evaluated SDO 211 Å images on a 12-hour cadence between June 2010 and June 2016. Each compact and isolated dim region we encountered was flagged as a potential ephemeral coronal hole for further analysis. This preliminary effort resulted in 149 candidate holes. For further analysis of their characteristics, we applied a strict definition criterion of an ephemeral coronal hole. This criterion was a set of four factors that were created in order to ensure events being observed were isolated, individual events-- the candidates had to be dark relative to the surrounding material, not influenced by a nearby eruption, not obviously connected to other coronal hole structures, and their lifetime had to occur completely within the disk crossing. This criterion was designed so that events could be completely analyzed, from beginning to end, to better understand the origins. Application of this criterion eliminated all candidates but 5 of the original 149.  True ephemeral coronal holes are rare occurrences, appearing only five times in six years. Future research in this area is needed to both locate additional events and study the underlying driving forces behind these rare phenomena.

Science Ctr B10                           Assembling and Preliminary Testing of the CMS GE1/1 chambers.

                                                                      Jessica Allan, Archana Sharma (CERN), Michele Bianco (CERN)

The CMS (Compact Muon Solenoid) detector is one of two general-purpose detectors currently collecting data at the LHC (Large Hadron Collider). It uses many layers of detecting material to record the products of proton-proton collisions, which are essential to building up the picture of what happened at the heart of the collision.  This means the detectors are constantly evolving and being upgraded with the latest technology, in order to collect the largest amount of data most efficiently. My project involved the testing of specially designed foils that will be installed into the Endcap of the CMS detector. Each foil will be combined into a chamber of three foils to produce a GEM (Gas Electron Multiplier) detector. I used a high voltage power supply, controlled by LabVIEW code I wrote, to test 8 foils simultaneously and ensure they were ready for assembly into GEM chambers, and for eventual installation during the second long shutdown in 2019. The test was conducted in a climate-controlled box, whose temperature and humidity I also monitored using data loggers. In the event of a failure, the foils would be taken back to their assembly site at CERN and modified in an attempt to fix the problem, though failure rate of foils was relatively low. I was able to test 120 foils, and they will continue to be tested until the 216 needed are deemed to be suitable.

Science Ctr 109       Developing TolTEC - a next-generation millimeter camera for the Large Millimeter Telescope.

                                                                                                       Miranda Eiben, Grant Wilson

Observations of the sky in the millimeter wavelength have the potential to illuminate a variety of key astronomical questions from “How do galaxies grow and evolve in the largest scale structures?” to “How can comets spread the ingredients for life?” TolTEC, a new camera for the Large Millimeter Telescope (LMT), will push the boundaries of current high-resolution millimeter observations by enabling rapid and deep mapping of the sky between 2 and 1mm wavelengths. TolTEC will increase the efficiency of the LMT’s mapping capabilities by two orders of magnitude, image the sky simultaneously in three mm-wavelength bands, and add a new polarimetric capability that will allow unique observations of the role of magnetic fields in star formation. This presentation highlights several key mechanical and thermal design considerations for the TolTEC system, including material choices and structural design.