PHY Research Publications (from 2011)

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The Department of Mathematics and Statistics and the Department of Physics have merged into the Department of Mathematics, Statistics, and Physics in summer 2011. This collection includes publication dated 2011-. For previous years, look at the Department of Physics collection in SOAR

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    Mössbauer spectral analysis and Rietveld structural refinement for cationic distribution of Cr-Co ferrites
    (Elsevier B.V., 2024-02) Beera, Chandra Sekhar; Dhanalakshmi, B.; Jyothula, Sudhakar; Vujji, Avinash; Ramesh, S.; Rao, B. Parvatheeswara; Hamdeh, Hussein H.
    Sol-gel autocombustion was used to prepare Chromium-substituted Cobalt ferrite nanoparticles with the chemical formulas CoCr${_x}$Fe$_{2-x}$O$_4$, with x (0.1 to 0.5 in steps of 0.1).The samples were systematically examined for providing information related to their structural aspects X-ray diffractometry and energy dispersive spectrometry and for determination of accurate ionic distribution using Mössbauer spectrometry and Rietveld structural refinement. The patterns obtained from the energy dispersive spectra ensure that the elemental concentrations of the samples match well with the ionic proportions set in the empirical formulae. Cationic distributions were first made by Mössbauer spectral analysis using hyperfine fields and then by Rietveld analysis based on integrated intensity ratios and profile matching. The results of the study are explained in terms of the compositional variations, cationic inversion degree associated with the fine particle nature of the materials and the relevant cationic distributions as a result of chromium substituted cobalt ferrite.
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    An efficient method to create high-density nitrogen-vacancy centers in CVD diamond for sensing applications
    (Elsevier Ltd, 2023-12) Karki, Prem Bahadur; Timalsina, Rupak; Dowran, Mohammadjavad; Aregbesola, Ayodimeji E.; Laraoui, Abdelghani; Ambal, Kapildeb
    The negatively charged Nitrogen-Vacancy (NV$^−$) center in diamond is one of the most versatile and robust quantum sensors suitable for quantum technologies, including magnetic field and temperature sensors. For precision sensing applications, densely packed NV$^−$ centers within a small volume are preferable due to benefiting from 1/$√N$ sensitivity enhancement ($N$ is the number of sensing NV centers) and efficient excitation of NV centers. However, methods for quickly and efficiently forming high concentrations of NV$^−$ centers are in the development stage. We report an efficient method for creating high-density NV$^−$ centers production from a relatively low nitrogen concentration based on high-energy photons generated from Ar$^+$ plasma source. This study was done on type-IIa, single crystal, chemical vapor deposition (CVD)-grown diamond substrates with an as-grown nitrogen concentration of 1 × 10$^{17}$ cm$^{−3}$. We created high NV$^−$ density (~20,000 NVs over the diffraction limited sample volume) distributed homogeneously over 150–200 μm deep from the diamond surface. The plasma-created NV$^−$s in CVD diamond have a spin-lattice relaxation time (T$_1$) of 5 ms and a spin-spin coherence time (T$_2$) of 4 μs. We measure a DC magnetic field sensitivity of ∼104 nT Hz$^{-1/2}$, an AC magnetic field sensitivity of ∼0.12 pT Hz$^{-1/2}$ and demonstrate real-time magnetic field sensing at a rate over 10 mT s$^{−1}$ using the diffraction limited sample volume.
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    Reconstruction of interactions in the ProtoDUNE-SP detector with Pandora
    (Institute for Ionics, 2023-07-14) DUNE Collaboration (over 1,200 authors); Solomey, Nickolas; Meyer, Holger; Muether, Mathew; Roy, P.
    The Pandora Software Development Kit and algorithm libraries provide pattern-recognition logic essential to the reconstruction of particle interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at ProtoDUNE-SP, a prototype for the Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at CERN, is exposed to a charged-particle test beam. This paper gives an overview of the Pandora reconstruction algorithms and how they have been tailored for use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam background particles, the simulated reconstruction and identification efficiency for triggered test-beam particles is above 80% for the majority of particle type and beam momentum combinations. Specifically, simulated 1 GeV/c charged pions and protons are correctly reconstructed and identified with efficiencies of 86.1±0.6% and 84.1±0.6%, respectively. The efficiencies measured for test-beam data are shown to be within 5% of those predicted by the simulation.
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    Impact of cross-section uncertainties on supernova neutrino spectral parameter fitting in the Deep Underground Neutrino Experiment
    (American Physical Society, 2023-06-29) DUNE Collaboration; Meyer, Holger; Muether, Mathew; Roy, P.; Solomey, Nickolas
    A primary goal of the upcoming Deep Underground Neutrino Experiment (DUNE) is to measure the $O(10) MeV$ neutrinos produced by a Galactic core-collapse supernova if one should occur during the lifetime of the experiment. The liquid-argon-based detectors planned for DUNE are expected to be uniquely sensitive to the $ν_e$ component of the supernova flux, enabling a wide variety of physics and astrophysics measurements. A key requirement for a correct interpretation of these measurements is a good understanding of the energy-dependent total cross section σ(E$_ν$) for charged-current $ν_e$ absorption on argon. In the context of a simulated extraction of supernova $ν_e$ spectral parameters from a toy analysis, we investigate the impact of σ(E$_ν$) modeling uncertainties on DUNE's supernova neutrino physics sensitivity for the first time. We find that the currently large theoretical uncertainties on σ(E$_ν$) must be substantially reduced before the $ν_e$ flux parameters can be extracted reliably; in the absence of external constraints, a measurement of the integrated neutrino luminosity with less than 10% bias with DUNE requires σ(E$_ν$) to be known to about 5%. The neutrino spectral shape parameters can be known to better than 10% for a 20% uncertainty on the cross-section scale, although they will be sensitive to uncertainties on the shape of σ(E$_ν$). A direct measurement of low-energy $ν_e$-argon scattering would be invaluable for improving the theoretical precision to the needed level.
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    Measurement of ν$_μ$ charged-current inclusive π$^0$ production in the NOvA near detector
    (American Physical Society, 2023-06-05) NOvA Collaboration; Meyer, Holger; Muether, Mathew; Solomey, Nickolas
    Cross sections for the interaction ν$_μ$ A → μ −π$^0$ X with neutrino energies between 1 and 5 GeV are measured using a sample of 165,000 selected events collected in the NOvA experiment's near detector, a hydrocarbon-based detector exposed to the Neutrinos from the Main Injector beam at the Fermi National Accelerator Laboratory. Results are presented as a flux-averaged total cross section and as differential cross sections in the momenta and angles of the outgoing muon and π$^0$, the total four-momentum transfer, and the invariant mass of the hadronic system. Comparisons are made with predictions from a reference version of the genie neutrino interaction generator. The measured total cross section of (3.57 ± 0.44) 10$^-39$ cm$^2$ is 7.5% higher than the genie prediction, but is consistent within experimental errors.