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Articles 1 - 30 of 46
Full-Text Articles in Physics
Projection Of Diffraction Patterns For Use In Cold-Neutral-Atom Trapping, Katharina Gillen-Christandl, Glen D. Gillen
Projection Of Diffraction Patterns For Use In Cold-Neutral-Atom Trapping, Katharina Gillen-Christandl, Glen D. Gillen
Physics
Scalar diffraction theory is combined with beam-propagation techniques to investigate the projection of near-field diffraction patterns to spatial locations away from the aperture for use in optically trapping cold neutral alkali-metal atoms. Calculations show that intensity distributions with localized bright and dark spots usually found within a millimeter of the diffracting aperture can be projected to a region free from optical components such as a cloud of cold atoms within a vacuum chamber. Calculations also predict that the critical properties of the optical dipole atom traps are not only maintained for the projected intensity patterns but also can be manipulated …
Could Alice Find The Elusive Higgs?, Tyler Williams
Could Alice Find The Elusive Higgs?, Tyler Williams
Physics
The Higgs boson is the theoretical mechanism for creating the mass of particles. Although it has never been seen, the CERN Large Hadron Collider (LHC) is the most likely place for it to be created in the laboratory. The ALICE (A Large Ion Collider Experiment) detector is focused on the study of heavy ion collisions at the LHC and was not designed to find the Higgs boson; however, there is a chance it could be detected there. Although the luminosity (collision rate) for PbPb collisions is much lower than that for pp collisions, PbPb collisions have a higher probability to …
Liquid Helium Refill Shifts At The Cryogenic Underground Observatory For Rare Events, Robin L. Reil
Liquid Helium Refill Shifts At The Cryogenic Underground Observatory For Rare Events, Robin L. Reil
Physics
No abstract provided.
The Lick Agn Monitoring Project: Alternate Routes To A Broad-Line Region Radius, Jenny E. Greene, Carol E. Hood, Aaron J. Barth, Vardha N. Bennert, Misty C. Benz, Alexei V. Filippenko, Elinor Gates, Matthew A. Malkan, Tommaso Treu, Jonelle L. Walsh, Jong-Hak Woo
The Lick Agn Monitoring Project: Alternate Routes To A Broad-Line Region Radius, Jenny E. Greene, Carol E. Hood, Aaron J. Barth, Vardha N. Bennert, Misty C. Benz, Alexei V. Filippenko, Elinor Gates, Matthew A. Malkan, Tommaso Treu, Jonelle L. Walsh, Jong-Hak Woo
Physics
It is now possible to estimate black hole (BH) masses across cosmic time, using broad emission lines in active galaxies. This technique informs our views of how galaxies and their central BHs coevolve. Unfortunately, there are many outstanding uncertainties associated with these "virial" mass estimates. One of these comes from using the accretion luminosity to infer a size for the broad-line region (BLR). Incorporating the new sample of low-luminosity active galaxies from our recent monitoring campaign at Lick Observatory, we recalibrate the radius-luminosity relation with tracers of the accretion luminosity other than the optical continuum. We find that the radius …
Construction And Improvement Of A Scheffler Reflector And Thermal Storage Device, Jason Rapp
Construction And Improvement Of A Scheffler Reflector And Thermal Storage Device, Jason Rapp
Physics
We constructed and successfully tested a 2 m2 parabolic dish solar concentrator (Scheffler Concentrator) to focus sunlight onto a stationary target. Present efforts are to decrease the construction complexity and cost of the concentrator. In order to store solar heat, we also constructed and are testing a thermal storage device made of sand (for thermal mass), and pumice (for insulation). Preliminary tests indicate thermal retention times of many hours. Present efforts are to increase accessible power, and structural integrity.
Rf System Models For The Cern Large Hadron Collider With Application To Longitudinal Dynamics, T. Mastorides, C. Rivetta, J.D. Fox, D. Van Winkle, P. Baudrenghien
Rf System Models For The Cern Large Hadron Collider With Application To Longitudinal Dynamics, T. Mastorides, C. Rivetta, J.D. Fox, D. Van Winkle, P. Baudrenghien
Physics
The LHC RF station-beam interaction strongly influences the longitudinal beam dynamics, both single bunch and collective effects. Non-linearities and noise generated within the Radio Frequency (RF) accelerating system interact with the beam and contribute to beam motion and longitudinal emittance blowup. Thus, the noise power spectrum of the RF accelerating voltage strongly affects the longitudinal beam distribution. Furthermore, the coupled-bunch instabilities are also directly affected by the RF components and the configuration of the Low Level RF (LLRF) feedback loops. In this work we present a formalism relating the longitudinal beam dynamics with the RF system configurations, an estimation of …
Veritas Search For Vhe Gamma-Ray Emission From Dwarf Spheroidal Galaxies, V. A. Acciari, T. Arlen, T. Aune, M. Beilicke, W. Benbow, D. Boltuch, S. M. Bradbury, J. H. Buckley, V. Bugaev, K. Byrum, A. Cannon, A. Cesarini, Jodi L. Christiansen, L. Ciupik, W. Cui, R. Dickherber, C. Duke, J. P. Finley, G. Finnegan, A. Furniss, N. Galante, S. Godambe, J. Grube, R. Guenette, G. Gyuk, D. Hanna, J. Holder, C. M. Hui, T. B. Humensky, A. Imran, P. Kaaret, N. Karlsson, M. Kertzman, D. Kieda, A. Konopelko, H. Krawczynski, F. Krennrich, G. Maier, S. Mcarthur, A. Mccann, M. Mccutcheon, P. Moriarty, R. A. Ong, A. N. Otte, D. Pandel, J. S. Perkins, M. Pohl, J. Quinn, K. Ragan, L. C. Reyes, P. T. Reynolds, E. Roache, H. J. Rose, M. Schroedter, G. H. Sembroski, G. D. Senturk, A. W. Smith, D. Steele, S. P. Swordy, G. Tesic, M. Theiling, S. Thibadeau, A. Varlotta, V. V. Vassiliev, S. Vincent, R. G. Wagner, S. P. Wakely, J. E. Ward, T. C. Weekes, A. Weinstein, T. Weisgarber, D. A. Williams, S. Wissel, B. Zitzer
Veritas Search For Vhe Gamma-Ray Emission From Dwarf Spheroidal Galaxies, V. A. Acciari, T. Arlen, T. Aune, M. Beilicke, W. Benbow, D. Boltuch, S. M. Bradbury, J. H. Buckley, V. Bugaev, K. Byrum, A. Cannon, A. Cesarini, Jodi L. Christiansen, L. Ciupik, W. Cui, R. Dickherber, C. Duke, J. P. Finley, G. Finnegan, A. Furniss, N. Galante, S. Godambe, J. Grube, R. Guenette, G. Gyuk, D. Hanna, J. Holder, C. M. Hui, T. B. Humensky, A. Imran, P. Kaaret, N. Karlsson, M. Kertzman, D. Kieda, A. Konopelko, H. Krawczynski, F. Krennrich, G. Maier, S. Mcarthur, A. Mccann, M. Mccutcheon, P. Moriarty, R. A. Ong, A. N. Otte, D. Pandel, J. S. Perkins, M. Pohl, J. Quinn, K. Ragan, L. C. Reyes, P. T. Reynolds, E. Roache, H. J. Rose, M. Schroedter, G. H. Sembroski, G. D. Senturk, A. W. Smith, D. Steele, S. P. Swordy, G. Tesic, M. Theiling, S. Thibadeau, A. Varlotta, V. V. Vassiliev, S. Vincent, R. G. Wagner, S. P. Wakely, J. E. Ward, T. C. Weekes, A. Weinstein, T. Weisgarber, D. A. Williams, S. Wissel, B. Zitzer
Physics
Indirect dark matter searches with ground-based gamma-ray observatories provide an alternative for identifying the particle nature of dark matter that is complementary to that of direct search or accelerator production experiments. We present the results of observations of the dwarf spheroidal galaxies Draco, Ursa Minor, Bootes 1, and Willman 1 conducted by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). These galaxies are nearby dark matter dominated objects located at a typical distance of several tens of kiloparsecs for which there are good measurements of the dark matter density profile from stellar velocity measurements. Since the conventional astrophysical background …
The Lick Agn Monitoring Project: Velocity-Delay Maps From The Maximum-Entropy Method For Arp 151, Misty C. Bentz, Keith Horne, Aaron J. Barth, Vardha Nicola Bennert, Gabriela Canalizo, Alexei V. Filippenko, Elinor L. Gates, Matthew A. Malkan, Takeo Minezaki, Tommaso Treu, Jong-Hak Woo, Jonelle L. Walsh
The Lick Agn Monitoring Project: Velocity-Delay Maps From The Maximum-Entropy Method For Arp 151, Misty C. Bentz, Keith Horne, Aaron J. Barth, Vardha Nicola Bennert, Gabriela Canalizo, Alexei V. Filippenko, Elinor L. Gates, Matthew A. Malkan, Takeo Minezaki, Tommaso Treu, Jong-Hak Woo, Jonelle L. Walsh
Physics
We present velocity-delay maps for optical H I, He I, and He II recombination lines in Arp 151, recovered by fitting a reverberation model to spectrophotometric monitoring data using the maximum-entropy method. H I response is detected over the range 0-15 days, with the response confined within the virial envelope. The Balmer-line maps have similar morphologies but exhibit radial stratification, with progressively longer delays for Hγ to Hβ to Hα. The He I and He II response is confined within 1-2 days. There is a deficit of prompt response in the Balmer-line cores but strong prompt response in the red …
U–Pb Zircon Geochronology And Tectonostratigraphy Of Southern Liverpool Land, East Greenland: Implications For Deformation In The Overriding Plates Of Continental Collisions, Scott M. Johnston, Ebbe H. Hartz, Hannes K. Brueckner, George E. Gehrels
U–Pb Zircon Geochronology And Tectonostratigraphy Of Southern Liverpool Land, East Greenland: Implications For Deformation In The Overriding Plates Of Continental Collisions, Scott M. Johnston, Ebbe H. Hartz, Hannes K. Brueckner, George E. Gehrels
Physics
The East Greenland Caledonides formed in the overriding plate as Baltica was subducted westward beneath Laurentia from 460 to 360 Ma, and offer a unique opportunity to investigate lower crustal deformation in the overriding plates of continental collisions. Field work and new zircon geochronology from gneisses in southern Liverpool Land, exposed in the hinterland ~100 km east of the nearest Caledonian gneisses, define three tectonostratigraphic units that are, from the bottom up, the eclogite+peridotite-bearing Tværdal complex and the granulite-facies Jættedal complex in the footwall of the top-N Gubbedalen shear zone, and the Hurry Inlet granite and associated paragneiss screens in …
Muon-Induced Backgrounds In The Cuoricino Experiment, E. Andreotti, C. Arnaboldi, F.T. Avignone Iii, M. Balata, I. Bandac, M. Barucci, J.W. Beeman, F. Bellini, T. Bloxham, C. Brofferio, A. Bryant, C. Bucci, L. Canonica, S. Capelli, L. Carbone, M. Carrettoni, M. Clemenza, O. Cremonesi, R.J. Creswick, S. Di Domizio, M.J. Dolinski, L. Ejzak, R. Faccini, H.A. Farach, E. Ferri, F. Ferroni, E. Fiorini, L. Foggetta, A. Giachero, L. Gironi, A. Giuliani, P. Gorla, E. Guardincerri, T.D. Gutierrez, E.E. Haller, R. Kadel, K. Kazkaz, S. Kraft, L. Kogler, Yu. G. Kolomensky, C. Maiano, R.H. Maruyama, C. Martinez, M. Martinez, L. Mizouni, S. Morganti, S. Nisi, C. Nones, E.B. Norman, A. Nucciotti, F. Orio, M. Pallavicini, V. Palmieri, L. Pattavina, M. Pavan, M. Pedretti, G. Pessina, S. Pirro, E. Previtali, L. Risegari, C. Rosenfeld, C. Rusconi, C. Salvioni, S. Sangiorgio, D. Schaeffer, N.D. Scielzo, M. Sisti, A.R. Smith, C. Tomei, G. Ventura, M. Vignati
Muon-Induced Backgrounds In The Cuoricino Experiment, E. Andreotti, C. Arnaboldi, F.T. Avignone Iii, M. Balata, I. Bandac, M. Barucci, J.W. Beeman, F. Bellini, T. Bloxham, C. Brofferio, A. Bryant, C. Bucci, L. Canonica, S. Capelli, L. Carbone, M. Carrettoni, M. Clemenza, O. Cremonesi, R.J. Creswick, S. Di Domizio, M.J. Dolinski, L. Ejzak, R. Faccini, H.A. Farach, E. Ferri, F. Ferroni, E. Fiorini, L. Foggetta, A. Giachero, L. Gironi, A. Giuliani, P. Gorla, E. Guardincerri, T.D. Gutierrez, E.E. Haller, R. Kadel, K. Kazkaz, S. Kraft, L. Kogler, Yu. G. Kolomensky, C. Maiano, R.H. Maruyama, C. Martinez, M. Martinez, L. Mizouni, S. Morganti, S. Nisi, C. Nones, E.B. Norman, A. Nucciotti, F. Orio, M. Pallavicini, V. Palmieri, L. Pattavina, M. Pavan, M. Pedretti, G. Pessina, S. Pirro, E. Previtali, L. Risegari, C. Rosenfeld, C. Rusconi, C. Salvioni, S. Sangiorgio, D. Schaeffer, N.D. Scielzo, M. Sisti, A.R. Smith, C. Tomei, G. Ventura, M. Vignati
Physics
To better understand the contribution of cosmic ray muons to the CUORICINO background, 10 plastic scintillator detectors were installed at the CUORICINO site and operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV kg yr) (95% CL) was obtained on the cosmic ray-induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to GEANT4 simulations.
Bottom Quark Detection With The Electromagnetic Calorimeter At Alice, Christopher Ryan Brown
Bottom Quark Detection With The Electromagnetic Calorimeter At Alice, Christopher Ryan Brown
Physics
Bottom quarks are one of the easiest ways to observe quark flow in a quark gluon plasma. For this reason, it is advantageous in a detector to have superb capabilities at detecting bottom quarks through their decay products and interactions. This paper will provide an overview of bottom quark behavior in a quark gluon plasma, as well as methods used to detect this behavior. Once this has been established, an overview of the heavy ion physics at the Large Hadron Collider (LHC), and particularly A Large Ion Collider Experiment (ALICE), will be discussed. It will then be argued that the …
The Lick Agn Monitoring Project: Reverberation Mapping Of Optical Hydrogen And Helium Recombination Lines, Misty C. Bentz, Jonelle L. Walsh, Aaron J. Barth, Yuzuru Yoshii, Jong-Hak Woo, Xiaofeng Wang, Tommaso Treu, Carol E. Thornton, Rachel A. Street, Thea N. Steele, Jeffrey M. Silverman, Frank J.D. Serduke, Yu Sakata, Takeo Minezaki, Matthew A. Malkan, Weidong Li, Nicholas Lee, Kyle D. Hiner, Marton G. Hidas, Jenny E. Greene, Elinor L. Gates, Mohan Ganeshalingam, Alexei V. Filippenko, Gabriela Canalizo, Vardha N. Bennert, Nairn Baliber
The Lick Agn Monitoring Project: Reverberation Mapping Of Optical Hydrogen And Helium Recombination Lines, Misty C. Bentz, Jonelle L. Walsh, Aaron J. Barth, Yuzuru Yoshii, Jong-Hak Woo, Xiaofeng Wang, Tommaso Treu, Carol E. Thornton, Rachel A. Street, Thea N. Steele, Jeffrey M. Silverman, Frank J.D. Serduke, Yu Sakata, Takeo Minezaki, Matthew A. Malkan, Weidong Li, Nicholas Lee, Kyle D. Hiner, Marton G. Hidas, Jenny E. Greene, Elinor L. Gates, Mohan Ganeshalingam, Alexei V. Filippenko, Gabriela Canalizo, Vardha N. Bennert, Nairn Baliber
Physics
We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3 m Shane telescope with the aim of measuring the masses of the black holes in 12 nearby (z < 0.05) Seyfert 1 galaxies with expected masses in the range ~106-107 M ☉ and also the well-studied nearby active galactic nucleus (AGN) NGC 5548. Nine of the objects in the sample (including NGC 5548) showed optical variability of sufficient strength during the monitoring campaign to allow for a time lag to be measured between the continuum fluctuations and the response to these fluctuations in the broad Hβ emission, which we have previously reported. We present …
The Lick Agn Monitoring Project: The M Bh-Σ* Relation For Reverberation-Mapped Active Galaxies, Jong-Hak Woo, Tommaso Treu, Aaron J. Barth, Shelley A. Wright, Jonelle L. Walsh, Misty C. Bentz, Paul Martini, Vardha N. Bennert, Gabriela Canalizo, Alexei V. Filippenko, Elinor Gates, Jenny Greene, Weidong Li, Matthew A. Malkan, Daniel Stern, Takeo Minezaki
The Lick Agn Monitoring Project: The M Bh-Σ* Relation For Reverberation-Mapped Active Galaxies, Jong-Hak Woo, Tommaso Treu, Aaron J. Barth, Shelley A. Wright, Jonelle L. Walsh, Misty C. Bentz, Paul Martini, Vardha N. Bennert, Gabriela Canalizo, Alexei V. Filippenko, Elinor Gates, Jenny Greene, Weidong Li, Matthew A. Malkan, Daniel Stern, Takeo Minezaki
Physics
To investigate the black hole mass versus stellar velocity dispersion (M BH-σ*) relation of active galaxies, we measured the velocity dispersions of a sample of local Seyfert 1 galaxies, for which we have recently determined black hole masses using reverberation mapping. For most objects, stellar velocity dispersions were measured from high signal-to-noise ratio optical spectra centered on the Ca II triplet region (~8500 Å), obtained at the Keck, Palomar, and Lick Observatories. For two objects, in which the Ca II triplet region was contaminated by nuclear emission, the measurement was based on high-quality H-band spectra …
Moderately Thermophilic Magnetotactic Bacteria From Hot Springs In Nevada, Christopher T. Lefevre, Fernanda Abreu, Marian L. Schimdt, Ulysses Lins, Richard B. Frankel, Brian P. Hedlund, Dennis A. Bazylinski
Moderately Thermophilic Magnetotactic Bacteria From Hot Springs In Nevada, Christopher T. Lefevre, Fernanda Abreu, Marian L. Schimdt, Ulysses Lins, Richard B. Frankel, Brian P. Hedlund, Dennis A. Bazylinski
Physics
Populations of a moderately thermophilic magnetotactic bacterium were discovered in Great Boiling Springs, Nevada, ranging from 32 to 63°C. Cells were small, Gram-negative, vibrioid to helicoid in morphology, and biomineralized a chain of bullet-shaped magnetite magnetosomes. Phylogenetically, based on 16S rRNA gene sequencing, the organism belongs to the phylum Nitrospirae.
Design And Construction Of A Thermal Diffusion Cloud Chamber, Alexander Donoghue
Design And Construction Of A Thermal Diffusion Cloud Chamber, Alexander Donoghue
Physics
This paper will cover the theory behind a thermal diffusion cloud chamber. In addition to that it will cover the process, thought and material used to construct two different cloud chambers. It will also discuss the effects of materials used in each chamber on the working of the chamber.
Resistance Of The Superconducting Material Ybco, Christopher Safranski
Resistance Of The Superconducting Material Ybco, Christopher Safranski
Physics
No abstract provided.
Cryogenic Refrigeration For Quantum Voltage Standards, Jeffrey Power
Cryogenic Refrigeration For Quantum Voltage Standards, Jeffrey Power
Physics
Currently the world maintains the voltage standard using a Josephson junction which makes use of the properties of superconductors and quantum tunneling. Current technology requires liquid He to cool the Josephson junctions to ~4 K to allow them to function as superconductors. He (l) is expensive and price is geographically dependent. Here we investigated using a cryocooler, modeled after a Gifford-McMahon Refrigerator, that could run on 120V (or a standard outlet) and used gaseous He as the working fluid –a less geographically dependent and inexpensive alternative to He (l). We found that indeed a standard outlet gaseous He compressor could …
Optical Coherence: Recreation Of The Experiment Of Thompson And Wolf, David Collins
Optical Coherence: Recreation Of The Experiment Of Thompson And Wolf, David Collins
Physics
The purpose of our experiment is to recreate the experiment done by Thompson and Wolf in 1957 on the measurement of optical coherence. What is novel about our approach is that it allows one to view the effects of source size on optical spatial coherence in real time.
Investigation Of Track-Cluster Matching Vs Track-Cell Matching In The Alice Detector At Cern, Kevin Coulombe
Investigation Of Track-Cluster Matching Vs Track-Cell Matching In The Alice Detector At Cern, Kevin Coulombe
Physics
The ALICE (A Large Ion Collider Experiment) Experiment is a detector that is one of four stationed at the CERN Large Hadron Collider. The goal of ALICE is to investigate the properties of the quark-gluon plasma, a new form of matter which only existed during the first microsecond of the Universe. ALICE measures the aftermath of the collision of two lead ions. Some information detected is the trajectory of the particles traveling through the tracking detectors and energy deposited in the calorimeters. Both the tracks and energy are required to determine the identities of the various particles as they travel …
Experiments On De Vries Liquid Crystals: A Software Approach, Austin Havens
Experiments On De Vries Liquid Crystals: A Software Approach, Austin Havens
Physics
This paper describes two programs I developed to facilitate the study of liquid crystals. The first program is a graphical user interface to increase the accuracy of the birefringence measurements , which relates to their orientational order, by using a camera. The second program was designed to help study the effects of time varying fields on liquid crystals by matching data from a recorded video to oscilloscope data in order to attach data from image analysis to the voltage applied to the cell.
Identification Of Bottom Quark Jets In Pb+Pb Collisions In Alice At The Lhc, Brandon Boswell
Identification Of Bottom Quark Jets In Pb+Pb Collisions In Alice At The Lhc, Brandon Boswell
Physics
In the near future, the Large Hadron Collider (LHC) will begin colliding lead ions together with energies high enough to produce a state of matter known as the Quark-Gluon Plasma (QGP). Simulations have shown that Bottom-quark-jets (B-jets) are expected to be produced in these collisions, and that these B-jets provide a useful probe into the nature of the QGP. The ALICE detector (A Large Ion Collider Experiment) at the LHC is designed to study the nature of the QGP. In this paper we investigate the effect of requiring that an electron be inside observed jets and how this improves the …
The Usage Of Smartphones In The Calculation Of Relativistic Time Dilation Effects At Meager Velocities, Leland Gregory
The Usage Of Smartphones In The Calculation Of Relativistic Time Dilation Effects At Meager Velocities, Leland Gregory
Physics
The theories of special and general relativity postulate that events are not simultaneous for different observers, and that different observer's times tick at different rates depending on relative velocity and the magnitude of the gravitational field they are in. This project seeks to design a program for use with smartphones that will calculate this change in time, in real time, and keep track of the discrepancies in time experienced between the observer and a stationary point on the surface of the earth.
Search For Dark Matter Annihilation In M5, Daniel Jackson
Search For Dark Matter Annihilation In M5, Daniel Jackson
Physics
We analyzed the Messier 5 (M5) globular cluster for dark matter annihilation using data from VERITAS (Very Energetic Radiation Imaging Telescope Array System) to improve the flux upper limit previously done by Michael McCutecheon. We used updated software and lower energy thresholds. VERITAS consists of four ground-based gamma-ray telescopes located at the Fred Lawrence Whipple Observatory in southern Arizona. Thirty-five 20 minute observations of M5 from VERITAS are used in our analysis. The observations were collected from February to March in 2009, for a total exposure time of 10.63 hours. Gamma-rays from dark matter annihilation were not found,
but better …
Lhc Beam Diffusion Dependence On Rf Noise: Models And Measurements, T. Mastoridis, C. Rivetta, J.D. Fox, D. Van Winkle, P. Baudrenghien, A. Butterworth, J. Molendijk
Lhc Beam Diffusion Dependence On Rf Noise: Models And Measurements, T. Mastoridis, C. Rivetta, J.D. Fox, D. Van Winkle, P. Baudrenghien, A. Butterworth, J. Molendijk
Physics
Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work.
Sps Ecloud Instabilities - Analysis Of Machine Studies And Implications For Ecloud Feedback, J.D. Fox, A. Bullitt, T. Mastoridis, G. Ndabashimiye, C. Rivetta, O. Turgut, D. Van Winkle, J. Byrd, M. Furman, J-L. Vay, W. Hofle, G. Rumolo, R. De Maria
Sps Ecloud Instabilities - Analysis Of Machine Studies And Implications For Ecloud Feedback, J.D. Fox, A. Bullitt, T. Mastoridis, G. Ndabashimiye, C. Rivetta, O. Turgut, D. Van Winkle, J. Byrd, M. Furman, J-L. Vay, W. Hofle, G. Rumolo, R. De Maria
Physics
The SPS at high intensities exhibits transverse singlebunch instabilities with signatures consistent with an Ecloud driven instability.[1] We present recent MD data from the SPS, details of the instrument technique and spectral analysis methods which help reveal complex vertical motion that develops within a subset of the injected bunch trains. The beam motion is detected via wideband exponential taper striplines and delta-sigma hybrids. The raw sum and difference data is sampled at 50 GHz with 1.8 GHz bandwidth. Sliding window FFT techniques and RMS motion techniques show the development of large vertical tune shifts on portions of the bunch of …
Commissioning Of The Lch Low Level Rf System Remote Configuration Tools, D. Van Winkle, C. Rivetta, T. Mastoridis, J. Fox, P. Baudrenghien, A. Butterworth, J. Molendijk
Commissioning Of The Lch Low Level Rf System Remote Configuration Tools, D. Van Winkle, C. Rivetta, T. Mastoridis, J. Fox, P. Baudrenghien, A. Butterworth, J. Molendijk
Physics
The LHC Low Level RF system (LLRF) is a complex multi-loop system used to regulate the superconductive cavity gap voltage as well as to reduce the impedance presented by RF stations to the beam. The RF system can have a profound impact on the stability of the beam; a mis-configured RF system has the potential of causing longitudinal instabilities, beam diffusion and beam loss. To configure the RF station for operation, a set of parameters in the LLRF multi-loop system have to be defined. Initial system commissioning as well as ongoing operation requires a consistent method of computer based remote …
Lessons Learned From Positon-Electron Project Low Level Rf And Longitudinal Feedback, J. Fox, Themis Mastorides, C. Rivetta, D. Van Winkle, D. Teytelman
Lessons Learned From Positon-Electron Project Low Level Rf And Longitudinal Feedback, J. Fox, Themis Mastorides, C. Rivetta, D. Van Winkle, D. Teytelman
Physics
The PEP-II B-Factory collider ended the final phase of operation at nearly twice the design current and 4X the design luminosity. To highlight the evolution from the original conceptual design through to the 1.2E34 final machine we choose one example each from the broadband feedback and from the LLRF system. They illustrate the original design estimation missed some very significant details, and how in the course of PEP-II operation unexpected difficulties led to significant insights and new approaches which allowed higher machine performance. We present valuable ”lessons learned” which are of interest to designers of next generation feedback and impedance …
Prospective Type Ia Supernova Surveys From Dome A, A. Kim, A. Bonissent, Jodi L. Christiansen, A. Ealet, L. Faccioli, L. Gladney, G. Kushner, E. Linder, C. Stoughton, L. Wang
Prospective Type Ia Supernova Surveys From Dome A, A. Kim, A. Bonissent, Jodi L. Christiansen, A. Ealet, L. Faccioli, L. Gladney, G. Kushner, E. Linder, C. Stoughton, L. Wang
Physics
Dome A, the highest plateau in Antarctica, is being developed as a site for an astronomical observatory. The planned telescopes and instrumentation and the unique site characteristics are conducive toward Type Ia supernova surveys for cosmology. A self-contained search and survey over five years can yield a spectro-photometric time series of ∼1000 z < 0.08 supernovae. These can serve to anchor the Hubble diagram and quantify the relationship between luminosities and heterogeneities within the Type Ia supernova class, reducing systematics. Larger aperture (>4-m) telescopes are capable of discovering supernovae shortly after explosion out to z ∼ 3. These can be fed to space telescopes, and can isolate systematics and extend the redshift range over which we measure the expansion history of the universe.
Construction And Enhancement Of Stereo Vacuum Tube Amplifier With Precision Machined Enclosure, Nikolaus (Nik) Glazar
Construction And Enhancement Of Stereo Vacuum Tube Amplifier With Precision Machined Enclosure, Nikolaus (Nik) Glazar
Physics
The purpose of this project was to build a high fidelity tube amplifier from a kit, and machine a beautiful enclosure to house the electronics. Improvements were made to the circuit, and the amplifier was then tested for audio performance.
An Analysis Of The Quasi Biennial Oscillation, Ozone And Thermal Damping, Kevin Jauregui
An Analysis Of The Quasi Biennial Oscillation, Ozone And Thermal Damping, Kevin Jauregui
Physics
No abstract provided.