11,852 research outputs found

    Gauge calibration by diffusion

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    Vacuum gage calibration by diffusing a known quantity of gas through a heated barrier into a gauge is examined. The gas flow raises the pressure in the gauge to known level and is then compared with the gauge's pressure reading

    Optimal Szeg\"o-Weinberger type inequalities

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    Denote with μ1(Ω;eh(x))\mu_{1}(\Omega;e^{h\left(|x|\right)}) the first nontrivial eigenvalue of the Neumann problem \begin{equation*} \left\{\begin{array}{lll} -\text{div}\left(e^{h\left(|x|\right)}\nabla u\right) =\mu e^{h\left(|x|\right)}u & \text{in} & \Omega & & \frac{\partial u}{\partial \nu}=0 & \text{on} & \partial \Omega , \end{array} \right. \end{equation*} where Ω\Omega is a bounded and Lipschitz domain in RN\mathbb{R}^{N}. Under suitable assumption on hh we prove that the ball centered at the origin is the unique set maximizing μ1(Ω;eh(x))\mu_{1}(\Omega;e^{h\left(|x|\right)}) among all Lipschitz bounded domains Ω\Omega of RN\mathbb{R}^{N} of prescribed eh(x)dxe^{h\left(|x|\right)}dx-measure and symmetric about the origin. Moreover, an example in the model case h(x)=x2,h\left(|x|\right) =|x|^{2}, shows that, in general, the assumption on the symmetry of the domain cannot be dropped. In the one-dimensional case, i.e. when Ω\Omega reduces to an interval (a,b),(a,b), we consider a wide class of weights (including both Gaussian and anti-Gaussian). We then describe the behavior of the eigenvalue as the interval (a,b)(a,b) slides along the xx-axis keeping fixed its weighted length

    Development of an accurate wide range ultra high vacuum gauge calibration method, 29 June 1966 - 28 February 1968

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    Calibration method and ultrahigh vacuum components for ionization gage and mass spectromete

    The Supersymmetric Fine-Tuning Problem and TeV-Scale Exotic Scalars

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    A general framework is presented for supersymmetric theories that do not suffer from fine-tuning in electroweak symmetry breaking. Supersymmetry is dynamically broken at a scale \Lambda \approx (10 - 100) TeV, which is transmitted to the supersymmetric standard model sector through standard model gauge interactions. The dynamical supersymmetry breaking sector possesses an approximate global SU(5) symmetry, whose SU(3) x SU(2) x U(1) subgroup is explicitly gauged and identified as the standard model gauge group. This SU(5) symmetry is dynamically broken at the scale \Lambda, leading to pseudo-Goldstone boson states, which we call xyons. We perform a detailed estimate for the xyon mass and find that it is naturally in the multi-TeV region. We study general properties of xyons, including their lifetime, and study their collider signatures. A generic signature is highly ionizing tracks caused by stable charged bound states of xyons, which may be observed at the LHC. We also consider cosmology in our scenario and find that a consistent picture can be obtained. Our framework is general and does not depend on the detailed structure of the Higgs sector, nor on the mechanism of gaugino mass generation.Comment: 53 pages, 7 figure

    Extension of gage calibration study in extreme high vacuum /orbitron and magnetron studies/

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    Orbitron and magnetron studies for gauge calibration in extreme high vacuu