Bulletin of the American Physical Society
Joint Spring 2011 Meeting of the New England Sections of the APS and the AAPT
Volume 56, Number 2
Friday–Saturday, April 8–9, 2011; Lowell, Massachusetts
Session C1: Poster Session (5:30-7:00PM) |
Hide Abstracts |
Room: UML ICC Lower Locks Room |
|
C1.00001: Apparatus for measuring speed through the Doppler frequency shift of sound Walter Schier The Doppler frequency shift of sound apparatus is based on a one meter diameter rotary table with a ``button'' speaker at its outer edge. A semicircular waveguide encloses half the periphery and has a microphone pickup on its wall at the midpoint. The tangential speed of the button speaker can be determined two ways for comparison. One method calculates speed from the frequency shift of sound, the other uses the repeat sound pattern. Agreement to one percent is possible at speeds of about 25 mph. In the lab the microphone output is fed successively to pairs of students at ten computer stations. Students must also perform an exercise in their lab report that introduces them to the red shifted wavelengths of receding galaxies at determined distances from the earth thus introducing them to Hubble's law, the concept of the ``Big Bang'', and their estimate of the age of the universe. [Preview Abstract] |
|
C1.00002: Harvesting energy from the sun---photovoltaic panel apparatus David Riccio, Walter Schier Two 11 cm x 18 cm photovoltaic panels are mounted on a modified ballistic pendulum apparatus that was retired from service in our labs. Its heavy base with pivoted arm provides a stable mount with angle adjustment. Residential PV panel installations group the panels both in series and in parallel, extract maximum power from these groupings, and deal with varying intensity due to changing light conditions. Measurements in the undergraduate lab with a bare light bulb simultaneously provide characteristic graphs of current vs voltage, power vs voltage, load resistance vs voltage for PV panels singly, in series, or in parallel. Also intensity dependence on angle and on distance to the light source are studied in the lab. A custom junction box with a variable load resistor connects the PV panels to PASCO's interface box with voltage and current leads. PASCO's Data Studio is used to record and analyze the graphs. [Preview Abstract] |
|
C1.00003: Implementing ILDs and Assessment in Small-enrollment, Calculus-based Physics Classes -- Lessons, Observations and Open Questions Deborah Mason-McCaffrey At Salem State, we offer a Physics minor, but most of our teaching load is support courses for other science majors and a lab sequence which satisfies the University's core education requirement. In three years of using assessments and ILDs in small-enrollment calculus-based Physics classes, there has been a significant implementation learning curve, there are encouraging results, a few cautions, and still some open questions to report. ILDs can be highly effective teaching tools. They do require significant advance preparation as well as a safe environment for student participation. Motivating students to do their best on assessment pre- and post-tests can also be difficult. Strategies for motivating assessment performance, experiments using clickers to encourage participation in ILDs, and modifying and developing home-grown ILDs are discussed. [Preview Abstract] |
|
C1.00004: Ultrasensitive Sensing through Nanophotonics Gary Smith In the summer of 2010, I was a participant in a summer RET experience hosted by Boston University's Electrical and Computer Engineering department. As a part of my experience, I worked with Prof. Hatice Altug to develop classroom materials that would introduce high school students to the promise of nano-scale science, while providing them with some essential conceptual background in the subject. This summer, with NSF support, I hope to develop this background further by helping my cooperating professor refine novel techniques her group has developed in constructing nanoplasmonic antenna arrays through lithographic techniques. I currently work as a physics teacher and science department head for a Massachusetts Catholic high school. [Preview Abstract] |
|
C1.00005: Geometric Laws in the Periodic Table of Elements Albert Khazan Despite many versions of the Periodic table of Elements were suggested, no one discussed the problem how the elements are connected to each other inside the Groups and Periods of the Table. As is known, the Groups are joined along the vertical (18 Groups in total), while the Periods are joined along the horizontal (7 Periods; we also suggest Period 8). Period 1 consists of 2 elements, Periods 2 and 3 : 8 elements each, Periods 4 and 5 : 18 elements each, Periods 6 and 7 : 32 elements each, and Period 8 : 37 elements. Dependency of the number of elements in each Period on its number is expressed with a broken line, described by equations of the respective linear intervals. It is shown that, according to the dependency of the common number of elements in each Period on its number, all Periods are joined into three sections, for the elements of all 18 Groups: Periods 1-3 (y=8x-6), Periods 3-5 (y=18x-36), Periods 5-7 (y=32x-106), Periods 7-8 (y=37x-141). For the elements of Group 1, we obtain a respective line. The region created by these two lines includes all elements of the Periodic Table (Khazan A. Progress in Physics, v.4, 2010, 64). [Preview Abstract] |
|
C1.00006: A new model for extracting the physical parameters from I-V curves of organic and inorganic solar cells Nadia Nehaoua, Yahia Chergui, Djamel Eddine Mekki Computer simulation is an important tool for investigating the behaviour of solar cell devices and for optimising their performance. So, an accurate extraction and optimization of solar cells and solar panel parameters are very important in improving the device quality during fabrication and in device modelling and simulation. In this paper, a new method for extracting parameters (series resistance $R_{s}$, shunt resistance $G_{sh}$, ideality factor $n$, saturation current $I_{s}$ and photocurrent $I_{ph})$ value is proposed. The proposed method deduces the characteristics curve of an ideal solar cell using the current-voltage characteristics curve measured and reported by solar cell manufacturers and calculates the difference between the deduced and actual measured curves. The method has been successfully applied to organic and inorganic solar cells under different condition of temperature and illumination. In addition, the precision of the proposed method is demonstrated by calculating the correlation between the I-V characteristics curve based on modelling parameters and the I-V curve actually measured employing a numerical method and we compare the extracted values with the experimental results and the calculated values obtained by other methods for proving its significance. [Preview Abstract] |
|
C1.00007: Correlation Functions and Glass Structure Y. Chergui, N. Nehaoua, B. Telghemti, S. Guemid, N.E. Deraddji, H. Belkhir, D.E. Mekki This work presents the use of molecular dynamics (MD) and the code of Dl Poly, in order to study the structure of fluoride glass after melting and quenching. We are realized the processing phase liquid-phase, simulating rapid quenching at different speeds to see the effect of quenching rate on the operation of the devitrification. This technique of simulation has become a powerful tool for investigating the microscopic behaviour of matter as well as for calculating macroscopic observable quantities. As basic results, we calculated the interatomic distance, angles and statistics, which help us to know the geometric form and the structure of PbF2. These results are in experimental agreement to those reported in literature. [Preview Abstract] |
|
C1.00008: Observation of Anomalous Potential Electric Energy in Distilled Water Under Solar Heating Florentin Smarandache, V. Christianto In this paper, we describe a very simple experiment with distilled water which could exhibit anomalous potential electrical energy with \textit{very minimum preparation energy}. While this observed excess energy here is less impressive than J-P. Beberian's and M. Porringa's, and the material used is also far less exotic than common LENR-CANR experiments, from the viewpoint of minimum preparation requirement --and therefore less barrier for rapid implementation--, it seems that further experiments could be recommended in order to verify and also to explore various implications of this new proposition. [Preview Abstract] |
|
C1.00009: Comparison of ultrasonic distillation to sparging of liquid mixtures Han Jung Park, Hye Yun Jung, Joseph Calo, Gerald Diebold The application of intense ultrasound to a liquid-gas interface results in the formation of an ultrasonic fountain and generates both mist and vapor from the liquid. Here, the composition of the vapor and aerosol above an ultrasonic fountain is determined as a function of irradiation time and compared with the results of sparging for five different solutions. The experimental apparatus for determining the efficiency of separation consists of a glass vessel containing a piezoelectric transducer driven at either 1.65 or 2.40 MHz. Dry nitrogen is passed over the ultrasonic fountain to remove the vapor and aerosol. The compositions of the liquid solutions are recorded as a function of irradiation time using gas chromatography, refractive index measurement, nuclear magnetic resonance, or spectrophotometry. Data are presented for ethanol-water and ethyl acetate-ethanol solutions, cobalt chloride in water, colloidal silica, and colloidal gold. The experiments show that ultrasonic distillation produces separations that are somewhat less complete than what is obtained using sparging. [Preview Abstract] |
|
C1.00010: Neutron Scattering Cross Section Measurements for $^{169}$TM via the Time-of-Flight Technique Afrim Alimeti, James Egan, Gunter Kegel This research entails the first direct neutron scattering cross section measurements for $^{169}$Tm via the time-of-flight technique. Neutron elastic and inelastic cross-section angular distributions were measured at 590-keV and 1000-keV incident neutron energies. Differential cross-section excitation functions were also measured in 0.1-MeV steps at 125$^{o}$ (scattering angle) from 495-keV to 1000-keV incident energy. The elastic measurements in the 0.5-MeV to 1.0-MeV incident neutron energy range compare favorably with the JENDL-4.0 evaluation based on nuclear reaction model calculations in the Japanese Evaluated Nuclear Data Library. The inelastic measurements are compared to JENDL-4.0 and to earlier measurements by Ko \textit{et al}. (\textit{Nucl. Phys.} \textbf{A679}, 147-162 (2000)) who used the (n,~n'~$\gamma )$ technique for states above 100 keV in excitation. The measurements were made using the UMass Lowell 5.5-MV Van de Graaff accelerator, operated in the pulsed and bunched beam mode, producing subnanosecond proton pulses at a 5-MHz repetition rate to generate neutrons via the $^{7}$Li(p,n)$^{7}$Be reaction in a thin metallic elemental lithium target. [Preview Abstract] |
|
C1.00011: Why 400 Years to Discover Countless Planets? Paul H. Carr In 1584, Dominican monk Giordano Bruno envisioned the stars as ``countless suns with countless earths, all rotating around their suns.'' Searching for intellectual freedom, he fled his native Italy to Protestant Switzerland and Germany, but in 1600 the Roman Inquisition condemned him for heresy. He was burned at the stake. Fast-forwarding to 1995, the Swiss astronomers Michel Mayor and Didier Queloz announced the discovery of a planet orbiting a star similar to our sun (51 Pegasi). In 2010, 500 planets had been found orbiting 421 stars. On Feb 2, 2011, NASA announced 1200 planet candidates. It took 400 years for telescope technology to advance and for Copernicus, Galileo, Newton, Bradley, and Foucault to make major contributions, culminating in today's astrophysics with digital imaging and processing. Contrasting with Bruno, in 2010 Dominican Francisco Ayala, who had been president of the Sigma Xi and AAAS, won the {\$}1.6M Templeton Prize for affirming life's spiritual dimension. [Preview Abstract] |
|
C1.00012: An alternative to Wave Particle Duality Jeffrey Boyd by Jeffrey H Boyd. It is incorrectly thought that there is a mountain of experimental data supporting wave particle duality, WPD. We present a theory, Theory of Elementary Waves, that equally well explains that mountain of data. TEW views waves as independent of particles. Wave interference is complete before a particle is emitted. Often the waves and particles travel in opposite directions. To support TEW we offer four experiments. One. The TEW explanation of the double slit experiment. Two. Neutron interferometer data that can be explained by TEW but not WPD. Three. A variation on the double slit experiment in which WPD and TEW predict different outcomes. Four. The TEW explanation of the Bell Test experiments. [Preview Abstract] |
|
C1.00013: Effect of Mechanical Boundary Conditions and Thermal Stresses on the Electrocaloric and Pyroelectric Properties of Ferroelectric Films Jialan Zhang, George. A. Rossetti, Jr., S. Pamir Alpay We use a non-linear thermodynamic model to describe quantitatively the electrothermal response of perovskite ferroelectric thin films under different electrical, thermal and mechanical boundary conditions. A comparison of ferroelectric materials such as BaTiO$_{3}$, PbTiO$_{3}$, and SrTiO$_{3}$ illustrates the influence of composition and lateral clamping effect on the electrocaloric properties. The theoretical analysis of a variety of (001)-textured polycrystalline ferroelectric thin films on IC-friendly substrates such as Si and sapphire shows that the thermal stresses that develop during processing shift the zero-field Curie temperature, and have a significant influence on the pyroelectric properties of thin film ferroelectric materials. We also demonstrate that the maximum in the electrocaloric properties can be shifted to a working temperature of interest by adjusting the deposition/processing temperature. These results provide insights on how to optimize pyroelectric and electrocaloric properties. [Preview Abstract] |
|
C1.00014: Heavy Element Spectroscopy: $^{244,245,246}$Pu (Z=94) Sankha Hota, P. Chowdhury, S. Lakshmi, S.K. Tandel, T. Harrington, E. Jackson, K. Moran, U. Shirwadkar, I. Ahmad, M.P. Carpenter, C.J. Chiara, J. Greene, C.R. Hoffman, R.V.F. Janssens, T.L. Khoo, F.G. Kondev, T. Lauritsen, C.J. Lister, E.A. McCutchan, D. Seweryniak, I. Stefanescu, S. Zhu We report new spectroscopic observations in the N=150,151,152 nuclei $^{244,245,246}$Pu (Z=94) in continuation of our exploration of heavy elements using deep-inelastic and transfer reactions. High-spin states in $^{244,245,246}$Pu were populated using a $^{208}$Pb beam from the ATLAS superconducting LINAC at Argonne National Laboratory, incident on a $^{244}$Pu target, with gamma rays detected by 101 high resolution high-purity Ge detectors of the Gammasphere array. New bands are observed in $^{244,245}$Pu and the ground state band in $^{246}$Pu has been extended to higher spins. The new results will be discussed in the context of the physics of neighboring N=150,151 and 152 even-Z isotones, along with expected high-K configurations and their decay modes in this region. The results help constrain theoretical models that attempt to describe the stability and structure of superheavy nuclei. [Preview Abstract] |
|
C1.00015: Enhanced sensitivity and reliability of a self-cleaning room temperature gas sensor Haizhou Ren, Haibin Huo, Pengtao Wang, Cong Wang, Sai Liu, Mengyan Shen, Hongwei Sun, Marina Ruths A room temperature SnO2 gas sensor with different sensitivity to CO and NH3 gases was fabricated on a silicon substrate with nanostructures formed by femtosecond laser irradiation in water. After deposition of a silane monolayer, the nanostructured sensor surface showed super hydrophobic wetting behavior and exhibited self-cleaning properties like lotus leaves. The reliability of the self-cleaning of the sensor was investigated under thousands of cleaning cycles and characterized by measurement of the sensitivity change during this cleaning process. [Preview Abstract] |
|
C1.00016: Characteristics of the Lakeshore Wind Measured with an Ultrasonic Anemometer Richard Stimets Time series of wind speed, wind direction and wind elevation at an altitude of 1.5 m above ground level at a lakeshore site on a lake in Maine have been recorded using an ultrasonic anemometer at a sampling rate of 10 Hz. The data have been analyzed to compute power spectra, correlation spectra and distribution functions of the various quantities. The power spectra of wind speed and wind direction typically have peaks in the frequency range of 0.002 Hz to 0.05 Hz (500 s to 20 s period); those of wind elevation peak at higher frequencies. Power-law behavior is often observed in the high-frequency regime although the numerical value of the exponent is variable. When the wind blows steadily from the east-southeast (stormy weather) and west (fair weather) directions the distribution functions of both wind speed and direction are close to normal Gaussian distribution functions. When the wind blows gustily from the northwest, often following the passage of a cold front, the distribution function of wind direction is bimodal and the distribution functions of wind speed are clearly non-Gaussian and are better fit by a gamma distribution function. [Preview Abstract] |
|
C1.00017: Correlation between Optical properties of 3D models and their 2D analogs Rahul Khanna, Sandeep Inampudi, Viktor Podolskiy It is widely known that numerical solutions of Maxwell equations in three dimensions require substantial memory and processor resources. For this reason, it is attractive to analyze the propagation of light in complex 3D waveguiding structures by studying the behavior of their simplified 2D analogs. In this project we study the validity of such approximations, using examples of abruptly terminated and bent waveguides, commonly used as laser cavities in quantum cascade lasers. [Preview Abstract] |
|
C1.00018: Photoacoustic effect in a periodically modulated structure Binbin Wu, Gerald Diebold We discuss the photoacoustic effect in one-dimensional phononic structures with sinusoidal modulation of its acoustic properties. The periodic structure is considered to have a modulation in its density or compressibility of the form $1-2\gamma \cos (\frac{2\pi x}{a})$, where $\gamma$ is the modulation factor and $a$ is the periodic length of the phononic structures. The properties of the photoacoustic waves are determined by an inhomogeneous Mathieu equation. We give several different methods including Green's function solutions, series expansions, and variation of parameters solutions for determining closed from solutions to the inhomogeneous Mathieu equation to obtain the properties of the photoacoustic effect. [Preview Abstract] |
|
C1.00019: Nuclear Spectroscopy using Novel, Position-Sensitive Detectors S. Lakshmi, P. Chowdhury, E. Jackson, S.S. Hota, S.K. Tandel, C.J. Lister, S. Gros, M. McClish, R. Farrel, K. Shah Novel, position-sensitive particle and gamma detectors were tested for applications in nuclear physics experiments. Angular correlation between the alpha particle decay of $^{224}$Ra to an excited state in $^{220}$Rn, and the subsequent gamma decay to the ground state in $^{220}$Rn was measured. A 1 inch$^{2}$ position-sensitive avalanche photo-diode (PSAPD) was used for detecting the alpha particles and a planar germanium double-sided strip detector (GeDSSD) for detecting the gamma rays. A large solid angle coverage has been achieved in a single, fixed geometry, due to the excellent position resolution of the PSAPD (400 microns) and the GeDSSD (5 mm) by positioning the detectors close to the source. Distortion correction algorithms for the PSAPD, pixel efficiencies, method of angle reconstruction and the measured angular correlation will be presented. [Preview Abstract] |
|
C1.00020: Discriminating Neutron-Gamma Waveforms from Novel Scintillation Detectors using Digital Pulse Processing T. Harrington, S. Lakshmi, P. Chowdhury, J. Glodo, K. Shah In this research, we report the results of neutron-$\gamma $ pulse shape discrimination studies performed with digital signal processing techniques. Two novel scintillator crystals, Cs$_{2}$LiLaBr$_{6}$ (CLLB) and Cs$_{2}$LiYCl$_{6}$ (CLYC), (provided by Radiation Monitoring Devices Inc.), which have different pulse shapes for neutron and $\gamma $-ray detection, were used to detect neutrons and $\gamma $-rays from a PuBe source enclosed in paraffin. Following digitization of the pulse waveforms with a 1 GHz Lecroy Digital Oscilloscope, a pulse shape discrimination algorithm was explored through custom C++ programs integrated within the ROOT analysis software developed at CERN. The selection of integration windows was optimized to provide the greatest separation between the two signals. The latest results for the CLYC and CLLB crystal will be presented and the neutron-$\gamma $ discrimination capabilities of the two detectors will be compared. [Preview Abstract] |
|
C1.00021: Mode Matching Analysis for Negative refraction in a two dimensional Plasmonic Metamaterial Sandeep Inampudi, Igor I. Smolyaninov, Viktor A. Podolskiy We present a theoretical analysis of negative refraction of surface plasmons in a plasmonic metamaterial formed by the periodic PMMA array on a gold surface. We used mode matching technique to analyze the dynamics of the plasmonic mode and its non trivial coupling to the free space waves and to the other guided modes of the system. Our analysis, based on the dispersion of the effective wavevector indicates the presence of a hyperbolic dispersion relation, consistent with the negative refraction. [Preview Abstract] |
|
C1.00022: Nanocoulomb Proton Burst Nicholas Borges, Kimyli Recca, Gregg Parker At the UMASS Lowell Van-de-Graph accelerator, we are required to provide proton irradiation doses which corresponds to proton charges much less than one $\mu $C. We found that machine regulation requires a proton beam of about 1 $\mu $A. We designed a shutter provided with a slit which allows us to irradiate a sample for a fraction of 1 second with a 1 $\mu $A beam. To determine the time, $\Delta $t, during which the shutter is open, we use a light beam. Our equipment consists of the following: a photomultiplier tube (BURLE S83010E) set up as a photodiode, an electrometer (KEITHLEY 6514), a HeNe laser and a shutter that interrupts the laser beam. We measure the photodiode current, I$_{0}$, with the shutter open and we measure the charge with the electrometer, Q=I$_{0}\Delta $t, delivered to the target which the shutter is operated. From this data we obtain $\Delta $t, the time during which the shutter permits the light beam to pass, and during which we would pass the proton beam. [Preview Abstract] |
|
C1.00023: Application of CeBr$_3$ Scintillator Crystals for Sub-Nanosecond Lifetime Measurements N. D'Olympia, S. Lakshmi, P. Chowdhury, E. Jackson, J. Glodo, K. Shah Ongoing efforts in the development of next generation radiation detectors has yielded several new scintillation crystals with gamma ray detection properties superior to more traditional materials. Amongst these so-called ``super'' scintillators is CeBr$_3$, which exhibits fast timing properties similar to that of LaBr$_3$ and BaF$_2$, as well as excellent energy resolution. The time resolution of CeBr$_3$ detectors has been found to be as low as 120 ps in coincidence measurements. We are currently investigating the use of CeBr$_3$ detectors for research in basic and applied nuclear physics involving fast timing measurements. In the work presented here, a pair of CeBr$_3$ detectors have been used to directly measure the half-life of a 1.48 ns isomer in $^{152}$Sm using the delayed coincidence technique and a multi-parameter data acquisition system. Further work is underway to apply this method for measuring sub-nanosecond lifetimes in isotopes created through thermal neutron capture at the UMass Lowell research reactor. [Preview Abstract] |
|
C1.00024: Bending Loss Optimization in Hollow Flexible Terahertz Waveguides Pallavi Doradla, C.S. Joseph, Jayant Kumar, Robert H. Giles Hollow, flexible, metal (Ag/Au) coated polycarbonate waveguides have been designed and fabricated for the transmission of Terahertz radiation. Attenuation characteristics of waveguides with bore diameters 4.1mm, 3.2mm, 2 mm were studied at two different wavelengths 215$\mu $m and 513$\mu $m. Minimal propagation loss of 2dB/m was achieved by coupling the lowest loss TE11 mode into the waveguide from an optically pumped terahertz laser. Maximal bending loss of 0.8dB was achieved for waveguides of bending radii 8, 13, 18cm and bending angles of 30 to 150 degrees. The investigation shows that a mode can be preserved in metal coated waveguide by launching the lowest order TE11 mode into a small bore hollow guide. Results will be presented during APS meeting. [Preview Abstract] |
|
C1.00025: Pion Identification Methods in Pion Photoproduction Measurements at MAX-lab Daniel Kelleher One of the unsolved problems in nuclear physics is describing the properties of nucleons in terms of the framework provided by Quantum Chromodynamics (QCD). To do this, the comparison of experimental measurement with theoretical predictions can be made for those reactions where both theory and experiment can be performed accurately. One reaction where this is possible is pion photoproduction near threshold, which is a fundamental reaction in which a photon interacts with a a proton or neutron to produce a pion. Theoretical approaches such as Chiral Perturbation Theory and model-independent partial-wave analysis can provide accurate predictions for this reaction. A program to measure the $\gamma p \rightarrow pi^+ n$ reaction is underway using the MAX-lab photon tagging facility in Lund, Sweden. One difficulty with these measurements is isolating the pion events from the large proton and electron background present in the counters. By searching for the extra energy deposited from the $\pi \rightarrow \mu$ decay, it is possible to reliably identify the pion events. This event identification technique will be discussed and additional tests used to confirm the reliability of this method will be shown. [Preview Abstract] |
|
C1.00026: Gain Calibrations for Scintillation Counters in Pion Photoproduction Measurements at MAX-lab Khayla England In nuclear science, researchers strive to describe the properties of nucleons in terms of the underlying quark structure. In order to do this, comparison of experimental measurements with theoretical calculations are made for those reactions where both theory and experiment can provide accurate answers. One such reaction is pion photoproduction near the threshold energy. This is a fundamental nuclear reaction in which a photon interacts with a proton or neutron to produce a pion. Measurements of the $\gamma p \rightarrow \pi^+ n$ reaction are being performed using the photon tagging facility located at MAX-lab in Lund, Sweden. The outgoing pions were detected in scintillation counters. To ensure the accuracy of the pion energy measurements, gain calibrations of the scintillation counters were made during the data acquisition period. The energy spectrum produced by $\gamma$-rays emitted from a Th-C source was recorded. These data were analyzed to determine the position of the Compton edge, which has a known energy. Daily calibrations enabled changes in the scintillation counter gains to be monitored and corrected for in the data analysis. Additionally, these data also provided an estimate of uncertainties in the pion energy determination. [Preview Abstract] |
|
C1.00027: Studying the Charge Transport Property through Fitting the Current of Carrier Extraction by Linearly Increasing Voltage (CELIV) Ke Yang, Jayant Kumar, Akshay Kokil, Ramaswamy Nagarajan, Nagarjuna Gavvalapalli, Dhandapani Venkataraman A new method of data processing based on CELIV experiments is developed to determine the semiconductors' mobility and conductivity. This method is to solve the differential equation governing the carrier extraction process, and use the numerical solution to predict the carrier extraction current and compare the prediction with the experimentally extracted current. The best fit is obtained by adjusting the mobility, conductivity and the dielectric constant automatically in computer program loops until the minimum current difference is reached. The condition for the conventional CELIV method that the dielectric relaxation time should be much longer or shorter than the transit time is not required for this fitting method. The mobility and the conductivity of a methoxy film are determined by this fitting method. The results are consistent with the results from Space Charge Limited Current (SCLC) measurements and the LCR meter measurements on the same film. [Preview Abstract] |
|
C1.00028: The Rare Isotope Breeder Upgrade to ATLAS at Argonne National Laboratory P.F. Bertone, F. Buchinger, S. Caldwell, A. Chaudhuri, P. Chowdhury, J.A. Clark, J.E. Crawford, A.Y. Deo, J.P. Greene, S. Gulick, F.G. Kondev, S. Lakshmi, D. Lascar, A.F. Levand, G. Li, C.J. Lister, C. Nair, R.C. Pardo, G. Savard, K.S. Sharma, M. Sternberg, T. Sun, J. Van Schelt, R. Vondrasek, B.J. Zabransky The CAlifornium Rare Isotope Breeder Upgrade (CARIBU) to the Argonne Tandem-Linac Accelerator System (ATLAS) represents a highly novel approach to producing radioactive ion beams (RIBs) for nuclear physics studies. There are currently only two RIB facilities in the US. When commissioned, CARIBU will provide many exciting new opportunities to extend basic science knowledge as well as yielding valuable data for applications. The presentation will provide a brief overview of the physics goals for the facility, the suite of experimental apparatus, and current status. [Preview Abstract] |
|
C1.00029: Development of Side-gated Carbon Nanotubes for Terahertz Studies Chris McKitterick, Joel Chudow, Daniel Santavicca, Daniel Prober The single-walled carbon nanotube is a truly one-dimensional conductor. The currently accepted theory describing propagation of electrons in the nanotube is Luttinger liquid theory, which predicts collective charge modes moving at a velocity greater than the Fermi velocity. By modeling the carbon nanotube as a transmission line, this propagation velocity can be determined from the standing wave resonances in the system. Due to the high resistance of carbon nanotubes, a length on the order of one micron must be used, resulting in resonances which occur at terahertz (THz) frequencies. These resonances can be measured using the heating of the nanotube electron system [1]. To avoid the use of a conducting substrate that absorbs THz, we use a side gate. We describe the development of nanotube samples with side gates for the proposed THz experiment. \\[4pt] [1] D.F. Santavicca, J.D. Chudow, D.E. Prober, M.S. Purewal and P. Kim, Nano Lett. 10, 4538 (2010). [Preview Abstract] |
|
C1.00030: Optical coupling to nanoscale superconducting transition edge sensors for GHz count rate near-IR single-photon detection Faustin Carter, Daniel Santavicca, Daniel Prober Detection of individual near-IR photons with GHz count rates, good timing resolution, and high quantum efficiency is important in a number of applications. These include quantum key distribution, single-photon classical communication, and CMOS imaging for defect analysis. We propose a nano-scale superconducting niobium transition edge sensor (TES). The extremely small detector volume allows for single-photon sensitivity at 4 K, with a much faster response time (nsec) than conventional TES detectors operating below 0.4 K. The proposed device is intrinsically photon number resolving, unlike a superconducting nanowire single-photon detector or an avalanche photodiode. Efficient photon coupling is achieved with a resonant near-IR planar antenna. This is non-trivial in the near-IR regime. We present numerical simulations of the optical coupling for such a device. [Preview Abstract] |
|
C1.00031: Spintronics and Transportation Richard Kriske The author has previously suggested that Fermi Energy Levels on the interior of nanotubes may be result in a novel transport mechanism that may on the one hand act as a QED mechanism and on the other as the normal Fermi Energy theory of Solid States. At this boundary between Classical and Quantum Physics many unexpected properties of Spintronics may be seen that could be useful for Computational and Electronic Devices. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700