Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"antiprotons"”.
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Electromagnetic extraction and annihilation of antiprotons for spacecraft propulsion
… for the extraction and long-term trapping of antiprotons from planetary magnetospheres is developed. The excitation via rotating magnetic field of an electron population within a distributed neutral plasma is shown to produce a large-scale magnetic field approximating a dipole with r-² or …
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SOLAR MODULATION OF GALACTIC COSMIC RAYS: TECHNIQUES & APPLICATIONS (SHOCK ACCELERATION, ANTIPROTONS)
… involves the solar modulation of galactic antiprotons. It appears that a recent low-energy measurement of these particles has given cosmic-ray theorists trouble devising an interstellar spectrum to fit the observations. Using a steady-state, spherically-symmetric, numerical modulation code, …
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Measurement of cosmic antiprotons with the alpha magnetic spectrometer aboard the International Space Station
A precision measurement of the cosmic antiproton ( -p) flux and the antiproton-to-proton flux ratio ( -p/p) made with the Alpha Magnetic Spectrometer aboard the International Space Station is presented. The measurement covers the absolute rigidity range from 1 to 450 GV, and is based on 3.49x105 -p …
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Cold trapped positrons and progress to cold antihydrogen
… or electrons over a wide range of conditions. Antiprotons are trapped, cooled, and stacked from the new Antiproton Decelerator facility for the first time. Combining positrons and antiprotons, we have demonstrated the first positron cooling of antiprotons. The cooling takes place in a 4.2 K, …
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ATRAP Buffer-Gas Positron Accumulator
… has produced antihydrogen by positron cooling of antiprotons and by a laser-controlled charge-exchange process. Both methods require large numbers of antiprotons and positrons (the constituent particles of antihydrogen). This dissertation describes the methods developed to increase the number of …
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Design Of A High Luminosity 100 Tev Proton Antiproton Collider
… momentum capture 12 times. At Fermilab, antiprotons were stochastically cooled in one Debuncher and one Accumulator ring. Because the stochastic cooling time scales as the number of particles, two options of 12 independent cooling systems are presented. One electron cooling ring might …
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A measurement of proton anti-proton going to anti-lambda lambda baryon near threshold
Using antiprotons from the Low Energy Antiproton Ring at CERN, an investigation of the reaction $\bar pp\to \bar\Lambda\Lambda$ at threshold has been completed. This work includes a thorough scan of the 2 MeV region where a hint of a cross section resonance had been observed. No such resonance is …
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A Measurement of `pp��`LL near threshold
Using antiprotons from the Low Energy Antiproton Ring at CERN, an investigation of the reaction pp -+ AA at threshold has been completed. This work includes a thorough scan of the 2 MeV region where a hint of a cross section resonance had been observed. No such resonance is evident in this work. In …
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Towards the formation of a forward-boosted beam of neutral antihydrogen for gravitational studies
… The AD is the sole source of bunched trappable antiprotons in the world: they are a key ingredient for the formation of antihydrogen. The AE ̄gIS experimental apparatus consists of multiple subsystems linked together, used in different combinations depending on the experiment’s needs (e.g. …
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A search for signatures of dark matter in the AMS-01 electron and antiproton spectrum
… -1 spectrum of AMS-01 (essentially electrons and antiprotons). To avoid model dependent complications we assume that the primary annihilation channel is through W+W- production. We use the galactic propagation software GALPROP to determine the dark matter spectra at Earth from a smooth isothermal …
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Identified particle transverse momentum distributions from AU + AU collisions at 62.4 GeV per nucleon pair
… (PT) distributions for pions, kaons, protons and antiprotons have been measured near mid-rapidity for Au+Au collisions at sNN = 62.4 GeV using the PHOBOS detector at the Relativistic Heavy-Ion Collider (RHIC) in Brookhaven National Laboratory. Particle identification is performed using the PHOBOS …
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The ruins of science : whatever happened to the Tevatron?
… early 1980s, the machine accelerated protons and antiprotons through its 4.26-mile ring of magnets and smashed them together in one of two 5,000 ton detectors that traced and measured the collision debris. Scientists then analyzed the results in search of new fundamental particles or a deeper …
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Applications of X-ray Instrumentation for Dark Matter Searches with Cosmic-ray Antiparticles
… In addition, the GAPS sensitivity to cosmic-ray antiprotons is demonstrated in this work using a full instrument simulation, event reconstruction, and models of solar and atmospheric effects. With its large geometric acceptance, GAPS will detect ∼500 cosmic antiprotons per flight, producing a …
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Using power spectra to look for anisotropies in ultra-high energy cosmic ray distributions
… In these simulations, I will track antiprotons, along with other possible cosmic ray primaries, through various models of galactic and extragalactic magnetic fields. Once they reach a certain distance, I will record their positions on the sky. These final positions will determine the …
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Positronium in the AEgIS experiment: study on its emission from nanochanneled samples and design of a new apparatus for Rydberg excitations
… in Rydberg states interacts with cooled trapped antiprotons. Since the charge exchange cross section depends on Ps velocity and quantum number, the velocity distribution of Ps emitted by a positron-positronium converter as well as its excitation in Rydberg states have to be studied and optimized. …
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From quarks to cold atoms: the phases of strongly-interacting systems
… of the highly anticipated Facility for Antiprotons and Ion Research (FAIR), the only known “laboratories” in which low temperature dense quark matter is encountered are the cores of neutron stars. Fortunately, the structure of these astrophysical objects is highly dependent upon the …
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An Accelerator Measurement of Atomic X-ray Yields in Exotic Atoms and Implications for an Antideuteron-Based Dark Matter Search
The General AntiParticle Spectrometer (GAPS) is a novel approach for indirect dark matter searches that exploits cosmic antideuterons. The low energy antideuteron provides a clean dark matter signature, since the antideuteron production by cosmic ray interactions is suppressed at low energy, while …