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Full-Text Articles in Physical Sciences and Mathematics
Applying Binomial Statistics To Weighted Monte Carlo, Sue Ellen Mccloskey, William C. Hall, Wilfred J. Braithwaite
Applying Binomial Statistics To Weighted Monte Carlo, Sue Ellen Mccloskey, William C. Hall, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
Weighted Monte Carlo calculations requiring a uniform sampling of the problem-space can suffer from diminished statistical significance because many, if not most, of the randomly-chosen sampling points contribute only slightly to the desired result. Their contribution is reduced in size due the variable-size of the weighting terms. In contrast, none of the randomly-chosen points which are favored by variable size weighting terms will have their statistical significance enhanced beyond that of just one random point in the Monte Carlo sampling. A Monte Carlo analysis was used in earlier work to verify both Gauss' Law and Newton's Shell Theorem. Both examples …
Continuous Monitoring Of Star's Main Time Projection Chamber, Wilfred J. Braithwaite, Edwin S. Braithwaite
Continuous Monitoring Of Star's Main Time Projection Chamber, Wilfred J. Braithwaite, Edwin S. Braithwaite
Journal of the Arkansas Academy of Science
STAR refers to the Solenoidal Tracking instrument At RHIC (the Relativistic Heavy Ion Collider). For momenta above 500 MeV/c charged kaons are not separated from pions within STAR's Main TPC (Time Projection Chamber) by track density alone and they are poorly separated below 500 MeV/c, even when using information from other sources like the vertex tracker. Within the TPC large numbers of kaons and pions decay into muons (and undetected neutrinos). Earlier work has shown parent pions and kaons whose decays are detected within a TPC may be distinguished uniquely from each other in a two-dimensional plot of muon-emission angle …
Using Labview To Synchronize An Infrared Diode Laser Spectrometer With A Pulsed Supersonic Jet Expansion, Philip Williams, Anthony Bednar, Eric Barnett, Scott W. Reeve
Using Labview To Synchronize An Infrared Diode Laser Spectrometer With A Pulsed Supersonic Jet Expansion, Philip Williams, Anthony Bednar, Eric Barnett, Scott W. Reeve
Journal of the Arkansas Academy of Science
We describe software developed with LabVIEW to provide operational control for an in-house infrared diode laser spectrometer that has been combined with a pulsed supersonic jet expansion sample source. Data were collected with this instrument using a modified version of the rapid-scanning method. A prerequisite in employing the rapid-scan detection scheme is that the modulation used to scan the laser be synchronized in time with the electrical signal used to trigger the pulsed gas valve. Software performance was evaluated by examining a series of rotation vibration (ro-vibrational) spectra for the carbon monoxide molecule in the five micron region of the …
Speed Cut-Off Point For Antiforce Waves, Mostafa Hemmati, Mathues Shane Doss, Eric L. George
Speed Cut-Off Point For Antiforce Waves, Mostafa Hemmati, Mathues Shane Doss, Eric L. George
Journal of the Arkansas Academy of Science
A one-dimensional, three-component, fluid model has been employed to investigate the existence of a speed cut-off point for antiforce breakdown waves. The term antiforce wave is used to identify breakdown waves for which the electric field force on electrons is in the opposite direction of wave propagation. The electron fluid-dynamical equations for antiforce waves are different from those of proforce waves. This presentation will address the difference in the set of equations for proforce and antiforce waves and the method of integration of the set of equations through the dynamical transition region for antiforce waves. Also, for antiforce waves, the …
Infrared Diode Laser Spectrometer For The Study Of Jet Cooled Gases, Anthony Bednar, Eric Barnett, Candace Lindsay, Trey Heath, Philip Williams, Mark Draganjac, Scott W. Reeve
Infrared Diode Laser Spectrometer For The Study Of Jet Cooled Gases, Anthony Bednar, Eric Barnett, Candace Lindsay, Trey Heath, Philip Williams, Mark Draganjac, Scott W. Reeve
Journal of the Arkansas Academy of Science
We have constructed a tunable, high resolution, infrared diode laser spectrometer and combined it with a pulsed supersonic jet expansion. A modified version of the Perry multipass cell has been incorporated into the spectrometer to increase the effective absorption path length. Performance capabilities of the spectrometer are evaluated by examining ro-vibrational spectra for the carbon monoxide molecule in the five micron region of the infrared. From these measurements, an instrumental absorption sensitivity is determined. Finally, since one of our immediate goals is the infrared study of jet cooled transition metal carbonyls, we present high resolution data obtained by entraining the …
Separating K+/- From Pi+/- Using In-Flight Decays To Mu+/- + Nu, Wilfred J. Braithwaite, Edwin S. Braithwaite
Separating K+/- From Pi+/- Using In-Flight Decays To Mu+/- + Nu, Wilfred J. Braithwaite, Edwin S. Braithwaite
Journal of the Arkansas Academy of Science
A method is presented for completely distinguishing between charged kaons and charged pions by using their charged muon (plus neutrino) decays (with neutrinos undetected) for meson laboratory momenta up to 1000 MeV/c. When either a charged kaon or a charged pion decays into a muon and a neutrino, momentum-energy (four-momentum) conservation will be used to provide unique "kinematic trajectories" for distinguishing kaon decays from pion decays when the change in three-momentum of the muon from that of either parent kaon or pion is measured (or simulated). Ina magnetic field, observation of a tracked particle showing a "kink" and/or a change …
Coplanarity Test For Selecting A Pair Of Charged-Particle Tracks Resulting From A Single Neutral-Particle Decay, Edwin S. Braithwaite, Wilfred J. Braithwaite
Coplanarity Test For Selecting A Pair Of Charged-Particle Tracks Resulting From A Single Neutral-Particle Decay, Edwin S. Braithwaite, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
It is hard to determine directly the position of a neutral subatomic particle, but when such a particle decays into a pair of charged particles, it is easy to determine the positions of the charged decay particles and thereby infer the position of the parent particle at the time of its decay. A minimum of two coordinate points for each of the two decay particles is needed to reconstruct the position of the parent vertex. The mathematics of the reconstruction process is inherently interesting, and it can be used to demonstrate to students the utility of some of the most …
Wave Profile For Proforce Current Bearing Waves, Mostafa Hemmati, Steven Young
Wave Profile For Proforce Current Bearing Waves, Mostafa Hemmati, Steven Young
Journal of the Arkansas Academy of Science
A complete wave profile for proforce style of breakdown waves with a current behind the shock front is discussed. The solution of the electron fluid dynamical equations in the sheath region for proforce current bearing waves conforms with the expected conditins for the values of the dynamical variables at the trailing edge of the wave. The wave profile for electric field and electron velocity, temperature, and number density are presented.
Measuring Strangeness Production From Relativisitic Collisions Between Pairs Of Nuclei Using A Vertex Time Projection Chamber, Christine A. Byrd, Wilfred J. Braithwaite
Measuring Strangeness Production From Relativisitic Collisions Between Pairs Of Nuclei Using A Vertex Time Projection Chamber, Christine A. Byrd, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
At collider energies of 200A-GeV, tracking of charged particle pairs originating from neutrals is dominated by singlystrange KJ.' decays. Counting the number ofsecondary vertex pairs is a method of measuring the strangeness production. The VTX is a four-layer micro-strip gas time projection chamber being designed for use with the STAR instrument in an experiment using the Relativistic Heavy Ion Collider under construction at Brookhaven National Laboratory. Simulated pixel data generated from CERN's Monte Carlo detector-modeling program Geant were put into tables using the TAS sorting structures available from the STAR Collaboration. The response of VTX was mapped for charged pion …
Proforce Waves: The Effect Of Current Behind The Shock Front On Wave Structure, Mostafa Hemmati, Steven Young
Proforce Waves: The Effect Of Current Behind The Shock Front On Wave Structure, Mostafa Hemmati, Steven Young
Journal of the Arkansas Academy of Science
Recently, the initial boundary conditions for proforce waves with a substantial current behind the shock front have been derived. Computer solutions of the Electron Fluid Dynamical equations meet the expected boundary conditions at the end of the sheath region. This paper will compare the wave structure for proforce waves with and without current behind the shock front.
Critical Energy Of Torus Knots, Fred Hickling, Wesley Davis, Heather Woolverton
Critical Energy Of Torus Knots, Fred Hickling, Wesley Davis, Heather Woolverton
Journal of the Arkansas Academy of Science
The energy of a smoothly parameterized knot y(t) is defined as rr\ i i lp7 \\dn dsdt Jo Jo \||7M-7(0f (D(t(s),T(t))) 2 j\\ds \\dt where D(y (s), y(t)) is the arc length between the two points y (s) and y(t) on the curve. Simple calculus based arguments are used to locate critical values of the energy functional for torus knots. Explicitly the curves given parametrically by °(«*)W = (V2°iSri).JSSBe V2 C s7nS are CriticalP ° intS ° fthe energy functional whenever a and b are relatively prime.
Optimizing Tracking Software For A Time Projection Chamber, Wilson H. Howe, Christine A. Byrd, Amber D. Climer, Wilfred J. Braithwaite, Jeffrey T. Mitchell
Optimizing Tracking Software For A Time Projection Chamber, Wilson H. Howe, Christine A. Byrd, Amber D. Climer, Wilfred J. Braithwaite, Jeffrey T. Mitchell
Journal of the Arkansas Academy of Science
International research collaborations will be using accelerators in the U.S. and Europe to produce and detect t5 phase transition in high-density nuclear matter called the Quark-Gluon Plasma, formed in collisions between pairs of A=200 nuclei, for projectiles with kinetic energies large compared to their rest mass energies. Each collaboration will use time projection chambers (TPC) to track thousands ofsecondary charged particles formed in the aftermath ofeach central primary collision. Creating and optimizing TPC tracking software is difficultinsuch a high multiplicity environment, particularly for particles with a low momentum (below 300 MeV/C). A thigh momenta, energy loss is low enough for …
Introduction To Monte Carlo Methods, Sue Ellen Mccloskey, Wilfred J. Braithwaite
Introduction To Monte Carlo Methods, Sue Ellen Mccloskey, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
Monte Carlo computer programming is becoming increasingly popular to those who use it, due to the ease with which complex problems may be formulated and solved. However, the growth of MC programming for small projects is inhibited by a frequent misconception of difficulty, inferred from the high level of complexity of problems solved in High Energy and Nuclear Physics using MC methods. In addition, few students of science and engineering are receiving exposure to the basic issues involved in the Monte Carlo process despite the ease with which MC can be used to solve classical physics problems, especially those problems …
Drift Chamber Utilizing Microstrip Readout For Testing A New Micro Tpc Concept, H. Weiman, W. G. Gong, S. Margetis, M. T. Burks, Wilfred J. Braithwaite, A. A. Rollefson
Drift Chamber Utilizing Microstrip Readout For Testing A New Micro Tpc Concept, H. Weiman, W. G. Gong, S. Margetis, M. T. Burks, Wilfred J. Braithwaite, A. A. Rollefson
Journal of the Arkansas Academy of Science
A drift chamber type radiation detector is being used to examine design criteria for a new type of detector called a micro Time Projection Chamber (micro TPC) which is being proposed for use in high energy nuclear physics experiments. The main advantage of the micro TPC detector is its very low radiation thickness compared to its silicon counterpart. The micro TPC is a charged-particle detector which willbe optimized for good two track resolution which is needed inahigh track density environment. Such performance requires low electron diffusion and high resolution readout. The diffusion willbe reduced bylimiting the drift distance to 15 …
Energy-Loss Particle Identification In 2-D Silicon Drift Detectors, G. Douglas Maudlin, A. A. Rollefson, Wilfred J. Braithwaite
Energy-Loss Particle Identification In 2-D Silicon Drift Detectors, G. Douglas Maudlin, A. A. Rollefson, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
A relatively new type of transducer known as the Silicon Drift Detector (SDD) has been fabricated onto thin silicon wafers. SDD operates like a miniature, high-resolution, 2-D Time-projection chamber. One of these devices can detect two dimensions of an ionizing particle's position, and its integrated electrical charge output level isproportional to the particle's energy loss through the silicon. An array ofSDD's, arranged in three coaxial cylinders, is being considered as part of an instrument surrounding the beam pipe of highly-relativistic colliding beam facility, where it would be used to simultaneously track individual paths of thousands of charged particles emerging from …
Computational Fluid Dynamics In Small Airway Models Of The Human Lung, G. Burnside, J. R. Hammersley, Rama N. Reddy, B. Catlin
Computational Fluid Dynamics In Small Airway Models Of The Human Lung, G. Burnside, J. R. Hammersley, Rama N. Reddy, B. Catlin
Journal of the Arkansas Academy of Science
The promise of gene replacement therapy for cystic fibrosis, the administration of drugs via inhalation therapy, and die deposition location of man-made airborne particulates all involve a more complete understanding of the fluid dynamics in the human lung. Flow in the larger airways may be measured through life-sized models directly, but the airways in the peripheral lung are too small and the flows are too complex to be studied in this manner. Computational models can be developed which will accurately represent both the geometric nature of the central airways and the fluid dynamics with in them. Two-dimensional and three-dimensional models …
Using The Cern Program-Library Graphics And Interactive Data Display, Morgan T. Burks, Wilson H. Howe, Christine A. Byrd, Wilfred J. Braithwaite
Using The Cern Program-Library Graphics And Interactive Data Display, Morgan T. Burks, Wilson H. Howe, Christine A. Byrd, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
Small scale Monte Carlo programming is growing rapidly due to the ease with which complex problems may be formulated by any programmer. These programmers may choose to exploit graphics and interactive displays available in the program library developed and maintained by CERN (the Center for European Nuclear Research). This paper outlines the use of graphics and interactive data display features of the CERN program library, developed for visualizing simulated data events in particle detectors. One example uses GEANT, CERN's Monte Carlo modeling program, to simulate 300 MeV/c protons incident on a silicon slab. Display packages for GEANT are available both …
Fluid Dynamics Model Of Data Acquisition And Date Analysis For High-Energy Physics, Charles M. Byrd, Christine A. Byrd, Wilson H. Howe, W. J. Braithwaite
Fluid Dynamics Model Of Data Acquisition And Date Analysis For High-Energy Physics, Charles M. Byrd, Christine A. Byrd, Wilson H. Howe, W. J. Braithwaite
Journal of the Arkansas Academy of Science
No abstract provided.
Compton Scattering Of Gamma-Rays From Electrons In Advanced Laboratory, Christine A. Byrd, Morgan T. Burks, Lawrence A. Yates, Wilfred J. Braithwaite
Compton Scattering Of Gamma-Rays From Electrons In Advanced Laboratory, Christine A. Byrd, Morgan T. Burks, Lawrence A. Yates, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
A kinematically-complete 2-body final state measurement of Compton scattering of 662-keV photons is presened, where both scattered photon energy and electron recoil energy are measured versus photon scattering angle, theta gamma. Passive collimation of the photon beam is avoided; each recoiling electron triggers a photon-scattering event providing active beam collimation. Recoiling electrons have low energies at small theta gamma, impairing electron detection efficiency. Examining the recoiling-electron energy spectra in coincidence with high-resolution gammas indicates a 1"x 1"NaI detector is superior to a 1"x1" NE-102 plastic scintillator as the active scattering material, for efficient recoil-electron detection. Electron efficiencies versus theta gamma …
User-Interface Coding For The Cern/Geant Nuclear Physics Program, David L. Roetzel, Wilfred J. Braithwaite
User-Interface Coding For The Cern/Geant Nuclear Physics Program, David L. Roetzel, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
Explanations will be given of the various user-written routines required by the Monte Carlo detector-modeling program GEANT, developed by CERN, the European Organization for Nuclear Research. User-written routines must be linked with the CERN library to accomplish the researcher's intentions. Examples will illustrate how GEANT passes information to subprograms needed to model events. Various data structures used by GEANT library calls and included in each user routine, are similarly illustrated. Both computational-speed and memory-size limitations need to be factored into the construction of a simulation model. This will constrain the calls used in the user-written routines. Examples are provided of …
Time Projection Chamber's Efficiency, Obtained Using Cern's Geant Code, Christine A. Byrd, Charles M. Byrd, Wilfred J. Braithwaite
Time Projection Chamber's Efficiency, Obtained Using Cern's Geant Code, Christine A. Byrd, Charles M. Byrd, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
Geometrical acceptance and reconstruction of tracks have been carried out for a Time Projection Chamber (TPC) used in Experiment NA35: the 35th experiment in the North Area of the Super Proton Synchrotron (SPS), located at the European Organization for Nuclear Research (CERN). NA35 used the SPS at CERN to produce 6.4 TeV beams of 32S for central collisions with Au nuclei. The TPC modeling effort used a modified version of CERN's Monte Carlo program GEANT, which simulates the response of the NA35 TPC to output from CERN's primary event generators. GEANT was used to simulate three-dimensional pixel data in the …
Ultraviolet Spectra Of Acetic Acid, Glycine, And Glyphosate, J. Scott Mcconnell, Rose M. Mcconnell, Lloyd R. Hossner
Ultraviolet Spectra Of Acetic Acid, Glycine, And Glyphosate, J. Scott Mcconnell, Rose M. Mcconnell, Lloyd R. Hossner
Journal of the Arkansas Academy of Science
The influence of pH on the ultraviolet spectra of 0.001, 0.005, and 0.010 M glyphosate, glycine, and acetic acid was investigated. Each dilution of each acid was adjusted to acidic, neutral, and basic pH values. Ultraviolet spectra were recorded from 300 to 200 nm for each acid-dilution-pH combination. The wavelength of maximum absorption (Lambdamax) of glyphosate and glycine was slightly higher in the high pH solutions than in the neutral and low pH solutions. The Lambdamax of acetic acid was apparently unaffected by changes in ph. Molar extinction coefficients (epsilon) at Lambdamax increased with pH for all three acids. Regression …
Monte Carlo Director Modeling And Display, Using The Cern Laboratory, Christine A. Byrd, Charles M. Byrd, Wilfred J. Braithwaite
Monte Carlo Director Modeling And Display, Using The Cern Laboratory, Christine A. Byrd, Charles M. Byrd, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
Detectors for high energy nuclear physics experiments are being modeled using programs developed and maintained at CERN, the European Organization for Nuclear Research. These programs include data handling and display routines, as well as those using random-sampling Monte Carlo techniques to calculate energy depositions for high energy particles as they pass through the various parts of the detector system. The complete CERN library has been imported for use with our Workstation computers in a multiple user environment. The enormous CERN Monte Carlo program GEANT(French for GIANT) tracks the progress of a particle through a detector on a simulated event-by-event basis. …
Schroedinger Equation With Spherically Averaged Potentials, C. A. Hughes
Schroedinger Equation With Spherically Averaged Potentials, C. A. Hughes
Journal of the Arkansas Academy of Science
Using a method adapted from few—body hyperspherical techniques, an approach to the solution of the Schroedinger equation with nonspherical potentials is discussed. The method is to spherically average the potential over spherical angles and then solve the resulting set of coupled differential equations. A discussion of how this method is applied to the Stark effect is presented.
Development Of A Variable Wavelength Flame Infrared Emission Gas Chromatography Detector, Weiqun Zhang, M. Keith Hudson, Mokhtar Mofidi
Development Of A Variable Wavelength Flame Infrared Emission Gas Chromatography Detector, Weiqun Zhang, M. Keith Hudson, Mokhtar Mofidi
Journal of the Arkansas Academy of Science
No abstract provided.
Comparison Of Two Models For Breakdown Waves, Debra Burris, Mostafa Hemmati
Comparison Of Two Models For Breakdown Waves, Debra Burris, Mostafa Hemmati
Journal of the Arkansas Academy of Science
In this paper, the two theories concerning the propagation of breakdown waves are compared. The two theories are as follows: 1. The photoionization theory, in which the driving force of the propagation is the electromagnetic radiation from the hot gas generated at the electrode with the greatest potential gradient. 2. The electron fluid dynamical theory, in which the driving force of the propagation is the partial pressure of the high temperature electron gas generated in the neighborhood of the pulsed electrode. Successes in explaining the experimental data will be compared.
Double Tuned Cosine Coil For Nmr Imaging/Microscopy, Roger M. Hawk, Rao P. Gullapalli, Dikoma P. Shungu
Double Tuned Cosine Coil For Nmr Imaging/Microscopy, Roger M. Hawk, Rao P. Gullapalli, Dikoma P. Shungu
Journal of the Arkansas Academy of Science
The fabrication of a cosine coil having unevenly distributed struts is detailed. Placing the struts in such a manner enables a standing wave at the desired frequency and, hence, only one resonance frequency is obtained. This study details the fabrication of a cosine coil tuned to the LJ-7 frequency (77.76 MHz) and then double-tuned to the H-1 frequency (200.1 MHz) when operated at 4.7 Tesla. Double-tuning is attained by placing an LC trap in series with a capacitor used to single-tune the coil. Also, a method is suggested by which a cosine coil can be broadbanded in the lower frequency …
K-Shell Ionization Measurements For Light Incident Icons, Rahul Mehta, George Bissinger
K-Shell Ionization Measurements For Light Incident Icons, Rahul Mehta, George Bissinger
Journal of the Arkansas Academy of Science
The ionization of the K-shell in targets of copper, silver, dysprosium and gold was investigated with incident ion beams of proton and helium ions in the range 0.5 MeV/u to 3 MeV/u. The x-rays were detected by a HpGe detector. K-shell x-ray production cross section were determined by normalization of the x-ray yield to the incident beam flux, the Rutherford-scattered ions and the nuclear-Coulomb excited gamma ray yield. The multiple normalization procedures minimize the errors in these cross section measurements. The data are compared with the predictions of the ECPSSR theory for K-shell ionization. The atomic number dependence of these …
Lightning: A Complex Natural Phenomenon That Defies Simple Analysis, Mostafa Hemmati
Lightning: A Complex Natural Phenomenon That Defies Simple Analysis, Mostafa Hemmati
Journal of the Arkansas Academy of Science
No abstract provided.
Rotational Symmetries Of Nuclear States: Spin Determinations In Advanced Laboratory, Wilfred J. Braithwaite
Rotational Symmetries Of Nuclear States: Spin Determinations In Advanced Laboratory, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
An advanced laboratory experiment is described which shows the connection between the rotational symmetries of nuclear states and the assignments of spins to discrete nuclear states. Standard angular correlation methods were used to study the two sequential gamma ray transitions in each ⁶⁰Ni nucleus, populated by unobserved beta decays from a weak radioactive ⁶⁰Co source. The chosen electronics and detectors were inexpensive and easy to operate. This experiment was extended to introduce students to real-world data acquisition, using finite-geometry detectors, which resulted in enormously larger coincident data rates.