Browsing Physics, Computer Science and Data Science (Physics) by Title
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- ItemA CT Scanner Using Coincidence Techniques(Houghton College, 2014-05-19) Finch, VictoriaA CT scanner has been designed which uses gamma rays produced by positron annihilation. A low-activity 22Na source produces the positrons, which, when they annihilate, create 0.511 MeV gamma rays travelling in opposite directions. These gamma rays can be used to image an object using NaI detectors that are collinear with the source. Requiring a coincidence between the detectors reduces background. LabVIEW software counted the number of gamma ray coincidences and translated and rotated a robotic table, allowing the attenuation to be measured along multiple beam paths through the object. Ultimately, the attenuation data can be used to reconstruct an image of the object being observed.
- ItemA Low Activity Mössbauer Source to Test General Relativity using the Transverse Doppler Effect(Houghton College, 2016-04-02) Gula, August; Yuly, MarkXXXV Annual Rochester Symposium for Physics Students, University of Rochester (Rochester, NY).
- ItemA Low-Cost Van de Graaff Accelerator(Houghton College, 2002-05-08) Winey, Brian AndrewA small, low-cost Van de Graaff electrostatic accelerator capable of accelerating electrons and producing bremsstrahlung x-rays has been constructed using components commonly found in most undergraduate physics laboratories. The electrons originate within the negative high-voltage terminal and are accelerated by a uniform electric field through an evacuated glass tube. Electron currents of up to 6 µA were collected in a Faraday cup. The end-point of the bremsstrahlung x-ray energy spectrum has been measured to be between 300 and 400 keV.
- ItemA Measurement of the 12C(n,2n)11C Cross-Section Needed for an Inertial Confinement Fusion Diagnostic(Houghton College, 2013-11-19) Hartshaw, Garrett; Love, Ian; Yuly, MarkHoughton College Science Colloquium, (Houghton, NY).
- ItemA Measurement of the 12C(n,2n)11C Cross-Section Needed for an Inertial Confinement Fusion Diagnostic(Houghton College, 2013-08-02) Hartshaw, Garrett; Love, Ian; Yuly, MarkGeneseo-Houghton Research Roundup, SUNY Geneseo (Geneseo, NY).
- ItemA Measurement of the 12C(n,2n)11C Cross-Section for Use as an Inertial Confinement Fusion Diagnostic(Houghton College, 2014-04-05) Hartshaw, Garrett; Yuly, MarkXXXIII Annual Rochester Symposium for Physics Students, University of Rochester (Rochester, NY).
- ItemA Measurement of the 12c(N,2n)11c Cross-Section for Use as an Inertial Confinement Fusion Diagnostic(Houghton College, 2014-05-06) Hartshaw, GarrettIn inertial confinement fusion (ICF), nuclear fusion reactions are initiated by bombarding a small fuel pellet with high power lasers. One ICF diagnostic involves measuring the high-energy neutron yield via activation of 12C, requiring an accurate value for the 12C(n,2n)11C cross-section. An experiment to determine this cross-section in the energy range of 20-27 MeV was performed using the tandem van de Graaff accelerator at Ohio University. Monoenergetic neutrons, produced via the T(d,n)α reaction, were allowed to strike targets of polyethylene and graphite. Target activation was determined by counting positron annihilations due to β+ decay using back-to-back NaI detectors and the neutron flux was determined indirectly via protons elastically scattered from the polyethylene target. The cross-section will be determined from the number of 11C present in the target after activation, the number of protons detected during activation, and the geometry of the experiment. Funded in part by a LLE contract through the DOE.
- ItemA Measurement of the Muon Magnetic Moment Using Cosmic Rays(Houghton College, 2001-11-03) Ely, David Richard; Kroening, Daniel Atkinson; Yuly, MarkThe muon magnetic moment is being measured via the decay of polarized cosmic-ray muons in a 44 G magnetic field. One, thick, 102.0 x 20.6 x 5.4 cm plastic scintillator detector was placed between two, 101.5 x 20.6 x 1.6 cm detectors in the uniform magnetic field produced by a solenoid. A veto-scintillator eliminated events from regions of non-uniform magnetic field. The time difference between when the muon stopped in the center detector and the detection of the decay positron was recorded for several thousand events. The decay positron is emitted along the direction of the precessing muon spin axis.Rochester Academy of Science, 28th Annual Paper Session, Nazareth College, Rochester NY. November 3, 2001.
- ItemA Measurement of the Muon Magnetic Moment Using Cosmic Rays(Houghton College, 2002-05-08) Kroening, DanielThe muon magnetic moment was measured via the decay of polarized cosmic-ray muons in a constant magnetic field with a three-scintillator detector system. Cosmic-ray muons stop in the central detector, precess in the magnetic field, and then decay by emitting positrons along the muon spin axis. A quantum-mechanical calculation allows the g-factor to be extracted from a measurement of the number of positrons emitted into one direction as a function of decay time. The results are t = 2.28 ± 0.07 µs (mean decay time) and g = 2.74 ± 0.20. Some possible explanations for the large value of g are discussed.
- ItemA New Evaporator for the Houghton College Deposition Chamber(Houghton College, 2022-04-08) Bowman, Matthew; Hoffman, BrandonXL Annual Rochester Symposium for Physics Students, University of Rochester, April 8, 2022.
- ItemA Novel 1st Generation Computed Tomography Scanner(Houghton College, 2003-12-19) Kingsley, NicholasA preliminary design for a first generation tomography scanner is being designed and constructed. The scanner uses Na-22 as the radiation source, with annihilation photons being counted by shielded NaI detectors. The novel design of the scanner allows a very weak radiation source to be used by taking advantage of the back-to-back 511 keV annihilation photons emitted after Na-22 B+ decay to improve the signal to noise ratio. The object being scanned will be translated and rotated systematically by computerized motor control using two motors attached to a standard rotary table.
- ItemA Parity Violation Experiment for Undergraduate Laboratories(Houghton College, 2017-04-01) Ganger, Michael; Yuly, MarkXXXVI Annual Rochester Symposium for Physics Students, University of Rochester (Rochester, NY).
- ItemA Parity Violation Experiment for Undergraduate Laboratories(Houghton College, 2017-05-19) Ganger, MichaelThe discovery of parity violation in weak interactions was a foundational discovery of the 20th century, first proposed by Lee and Yang in 1956 and experimentally verified by Wu in 1957. Lee and Yang also proposed a simpler experiment which does not require that the 60Co source be polarized. Randomly oriented 60Co beta decays to an excited state of 60Ni, which then deexcites by emitting two gamma rays. Conservation of angular momentum ensures that the spins of all emitted particles are aligned. Therefore, when a gamma ray and a beta particle have antiparallel momenta they necessarily have opposite helicities. In the proposed experiment, these circularly polarized gamma rays are transmitted through a steel rod magnetized along the axis between two collinear detectors, a germanium detector for the gamma rays and a silicon detector for the beta particles. Due to the slight dependence of the Compton scattering cross-section on the relative orientations of the gamma rays and the electron spins in the magnet, a parity violating asymmetry may be observed by comparing beta particle and transmitted gamma ray coincidence count rates for opposite directions of magnetization. An experiment to observe effect this is currently being prepared at Houghton College using modern techniques suitable for an undergraduate laboratory.
- ItemA Phoswich Detector System to Measure Sub-Second Half-Lives using ICF Reactions(Houghton College, 2017-10-23) Coats, Micah; Cook, Katelyn; Yuly, Mark; Padalino, Stephen; Sangster, Craig; Regan, SeanThe 3H(t,γ)6He cross section has not been measured at any bombarding energy due to the difficulties of simultaneously producing both a tritium beam and target at accelerator labs. An alternative technique may be to use an ICF tt implosion at the OMEGA Laser Facility. The 3H(t,γ)6He cross section could be determined in situ by measuring the beta decay of 6He beginning a few milliseconds after the shot along with other ICF diagnostics. A dE-E phoswich system capable of surviving in the OMEGA target chamber was tested using the SUNY Geneseo pelletron to create neutrons via 2H(d,n)3He and subsequently 6He via 9Be(n,α)6He in a beryllium target. The phoswich dE-E detector system was used to select beta decay events and measure the 807 ms halflife of 6He. It is composed of a thin, 2 ns decay time dE scintillator optically coupled to a thick, 285 ns E scintillator, with a linear gate to separate the short dE pulse from the longer E tail. Funded in part by a grant from the DOE through the Laboratory for Laser Energetics.Omega Laser User’s Group Meeting, Laboratory for Laser Energetics, Rochester, NY, April 25, 2018; XXXVII Annual Rochester Symposium for Physics Students, SUNY Brockport, Brockport, NY., April 7, 2018; 59th Annual Meeting of the APS Division of Plasma Physics, Milwaukee, WI, Oct. 23-27, 2017; 2017 APS Division of Plasma Physics Outstanding Undergraduate Poster Award; 2018 Omega Laser Facility Users Group Workshop Student Poster Award.
- ItemA possible 12C(n,2n)11C total cross section measurement(Houghton College, 2011-11-14) Evans, Andrew; Mann, Keith; Yuly, MarkTertiary neutron production can be used as an indicator of the burn fraction of a deuterium-tritium pellet in inertial confinement fusion reactions. One way to monitor tertiary neutrons is by carbon activation using the 12C(n,2n)11C reaction, which has a threshold of 20.3 MeV and so is insensitive to primary neutrons produced in the DT reaction. However, the cross section for this reaction is not well known. Several different experimental techniques for measuring 12C(n,2n) have been examined, with an activation experiment being the most feasible.XXXI Annual Rochester Symposium for Physics Students, Siena College, Loudonville, NY, April 14, 2012; 53rd Annual Meeting of the APS Division of Plasma Physics, Salt Lake City, Utah, November 14-18, 2011.
- ItemA Preliminary Design for a Small Permanent Magnet Cyclotron(Houghton College, 2002-11-22) King, BarryHoughton College Interdisciplinary Lunch Seminar.
- ItemA Preliminary Design for a Small Permanent Magnet Cyclotron(Houghton College, 2003-01-20) King, BarryA small cyclotron is being constructed using a 0.5 T permanent magnet and a vacuum chamber containing a single brass RF electrode. In this design the magnetic field strength may be modified by adjusting the separation of two iron pole pieces, which will be sealed to the chamber using vacuum grease. The chamber will be filled with low pressure hydrogen gas which will be ionized by electrons from a cathode at the center of the chamber. The required 3.6 to 11.5 MHz RF power will be supplied by a commercial RF amplifier. A diffusion pump backed by a voluntary forepump and a liquid nitrogen cold trap will be used to evacuate the chamber. Expected energies are 37.5 keV and 87.7 keV for protons and 18.7 keV and 43.8 keV for deuterons.
- ItemA Preliminary Transmission Computed Tomography Scanner(Houghton College, 2003-11-15) Kingsley, Nicholas; Rohe, Ronald30th Annual Scientific Paper Session of the Rochester Academy of Science (Rochester, NY).