The effect of multiple B+ implantation on 109 μm square single-domain magneto-optic elements formed by chemical etching of Bi-doped Tm:YIG epitaxial films ( \sim 7 \mu m) is investigated by measuring ...the external switching field H sw sw required to reverse the magnetization \bar{M_{s}} as a function of implant profile, dosage, and the angle θ between the field and the film normal. For low doses (< 0.15% strain), switching is determined by coherent rotation in the implanted layer; H sw decreases linearly ( \lambda_{111} = -5.5 \times 10^{-6,} \theta = 0\deg ) from H k . 4πM s = 3995 Oe to 566 Oe and H sw (θ) is the classic switching curve for a uniaxial anisotropy. For higher doses, H sw remains constant or increases slightly, and H sw (\theta) \propto (\cos\theta)^{-1} , indicating that switching is limited by wall motion, and the force proportional to \nablaH_{k} at the implant/bulk interface. With annealing H sw increases for low dose as H k increases, and decreases for higher doses as \nablaH_{k} decreases. Measurements width three stain profiles intricate that more gradual strain transitions produce lower H sw due to decreased \nablaH_{k} .
Magnetic oxide films Mee, J.; Pulliam, G.; Archer, J. ...
IEEE transactions on magnetics,
12/1969, Letnik:
5, Številka:
4
Journal Article
Polycrystalline and epitaxial magnetic oxide films have been fabricated by several investigators. This paper deals predominantly with epitaxial films grown by chemical vapor deposition. The majority ...of the discussion is concerned with substrates, the deposition process, and film characterization. Where possible, comparisons are made with bulk crystals and with films produced by other fabrication techniques.
MicroBooNE is a near-surface liquid argon (LAr) time projection chamber (TPC) located at Fermilab. We measure the characterisation of muons originating from cosmic interactions in the atmosphere ...using both the charge collection and light readout detectors. The data is compared with the CORSIKA cosmic-ray simulation. Good agreement is found between the observation, simulation and previous results. Furthermore, the angular resolution of the reconstructed muons inside the TPC is studied in simulation.
We present the first measurement of the negative pion total hadronic cross
section on argon, which we performed at the Liquid Argon In A Testbeam (LArIAT)
experiment. All hadronic reaction channels, ...as well as hadronic elastic
interactions with scattering angle greater than 5~degrees are included. The
pions have a kinetic energies in the range 100-700~MeV and are produced by a
beam of charged particles impinging on a solid target at the Fermilab Test Beam
Facility. LArIAT employs a 0.24~ton active mass Liquid Argon Time Projection
Chamber (LArTPC) to measure the pion hadronic interactions. For this
measurement, LArIAT has developed the ``thin slice method", a new technique to
measure cross sections with LArTPCs. While generally higher than the
prediction, our measurement of the ($\pi^-$,Ar) total hadronic cross section is
in agreement with the prediction of the Geant4 model when considering a model
uncertainty of $\sim$5.1\%.
We describe algorithms developed to isolate and accurately reconstruct two-track events that are contained within the MicroBooNE detector. This method is optimized to reconstruct two tracks of ...lengths longer than 5 cm. This code has applications to searches for neutrino oscillations and measurements of cross sections using quasi-elastic-like charged current events. The algorithms we discuss will be applicable to all detectors running in Fermilab's Short Baseline Neutrino program (SBN), and to any future liquid argon time projection chamber (LArTPC) experiment with beam energies ~1 GeV. The algorithms are publicly available on a GITHUB repository. This reconstruction offers a complementary and independent alternative to the Pandora reconstruction package currently in use in LArTPC experiments, and provides similar reconstruction performance for two-track events.
We describe a method used to calibrate the position- and time-dependent response of the MicroBooNE liquid argon time projection chamber anode wires to ionization particle energy loss. The method ...makes use of crossing cosmic-ray muons to partially correct anode wire signals for multiple effects as a function of time and position, including cross-connected TPC wires, space charge effects, electron attachment to impurities, diffusion, and recombination. The overall energy scale is then determined using fully-contained beam-induced muons originating and stopping in the active region of the detector. Using this method, we obtain an absolute energy scale uncertainty of 2\% in data. We use stopping protons to further refine the relation between the measured charge and the energy loss for highly-ionizing particles. This data-driven detector calibration improves both the measurement of total deposited energy and particle identification based on energy loss per unit length as a function of residual range. As an example, the proton selection efficiency is increased by 2\% after detector calibration.
We present upper limits on the production of heavy neutral leptons (HNLs) decaying to \(\mu \pi\) pairs using data collected with the MicroBooNE liquid-argon time projection chamber (TPC) operating ...at Fermilab. This search is the first of its kind performed in a liquid-argon TPC. We use data collected in 2017 and 2018 corresponding to an exposure of \(2.0 \times 10^{20}\) protons on target from the Fermilab Booster Neutrino Beam, which produces mainly muon neutrinos with an average energy of \(\approx 800\) MeV. HNLs with higher mass are expected to have a longer time-of-flight to the liquid-argon TPC than Standard Model neutrinos. The data are therefore recorded with a dedicated trigger configured to detect HNL decays that occur after the neutrino spill reaches the detector. We set upper limits at the \(90\%\) confidence level on the element \(\lvert U_{\mu4}\rvert^2\) of the extended PMNS mixing matrix in the range \(\lvert U_{\mu4}\rvert^2<(6.6\)-\(0.9)\times 10^{-7}\) for Dirac HNLs and \(\lvert U_{\mu4}\rvert^2<(4.7\)-\(0.7)\times 10^{-7}\) for Majorana HNLs, assuming HNL masses between \(260\) and \(385\) MeV and \(\lvert U_{e 4}\rvert^2 = \lvert U_{\tau 4}\rvert^2 = 0\).
