18,406 research outputs found

    A new study of muons in air showers by NBU air shower array

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    The North Bengal University (NBU) air shower array has been in operation in conjunction with two muon magnetic spectrographs. The array incorporates 21 particle density sampling detectors around the magnetic spectrographs covering an area of 900 sq m. The layout of the array is based on the arrangement of detectors in a square symmetry. The array set up on the ground level is around a 10 m high magnetic spectrograph housing. This magnetic spectrograph housing limits the zenith angular acceptance of the incident showers to a few degrees. Three hundred muons in the fitted showers of size range 10 to the 4th power to 10 to the 5th power particles have so far been scanned and the momenta determined in the momentum range 2 - 440 GeV/c. More than 1500 recorded showers are now in the process of scanning and fitting. A lateral distribution of muons of energy greater than 300 MeV in the shower size range 10 to the 5th power to 7 x 10 to the 5th power has been obtained

    A Study on Local Moments and Charge Fluctuation in Mixed-Valence Systems

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    An attempt is made to study local moments and charge fluctuation in mixed valence systems. Model Hamiltonian approach has been accepted. Role of f-f Coulomb interaction and electron-phonon (EP) interaction is investigated. A comparison is also made with few existing results

    CMAC Trained Optimum Mid course Guidance for Tactical Flight Vehicle

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    This paper discusses design and validation of neural network based mid-course guidance law of a surface to air flight vehicle. In present study, initially different optimal trajectories have been generated off-line of different pursuer-evader engagements by ensuring minimum flight time, maximum terminal velocity and favorable handing over conditions for seeker based terminal guidance. These optimal trajectories have been evolved by nonlinear programming based direct method of optimisation. The kinematic information of both pursuer and evader, generated based on these trajectories have been used to train cerebellar model articulate controller (CMAC) neural network. Later for a given engagement scenario an on-line near optimal mid-course guidance law has been evolved based on output of trained network. Training has been carried out by CMAC type supervisory neural network. The tested engagement condition is within input/output training space of neural network. Seeker based homing guidance has been used for terminal phase. Complete methodology has been validated along pitch plane of pursuer-evader engagement. During mid-course phase, the guidance demand has been tracked by attitude hold autopilot and during terminal phase, the guidance demanded lateral acceleration has been tracked by acceleration autopilot. System robustness has been studied in presence of plant parameter variations and sensor noise under Monte Carlo Platform

    High-spin structure and Band Termination in 103^{103}Cd

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    Excited states of the neutron deficient 103^{103}Cd nucleus have been investigated via the 72^{72}Ge(35^{35}Cl, p3n) reaction at beam energy of 135 MeV by use of in-beam spectroscopic methods. Gamma rays depopulating the excited states were detected using the Gammasphere spectrometer with high-fold γ\gamma-ray coincidences. A quadrupole γ\gamma-ray coincidence analysis (γ4\gamma^{4}) has been used to extend the known level scheme. The positive parity levels have been established up to J=35/2J = 35/2\hbar and Ex=7.071E_{x} = 7.071 MeV. In addition to the observation of highly-fragmented level scheme belonging to the positive-parity sequences at Ex_{x}\sim 5 MeV, the termination of a negative-parity sequence connected by E2E2 transitions has been established at J=47/2J = 47/2 \hbar and Ex=11.877E_{x} = 11.877 MeV. The experimental results corresponding to both the positive- and negative-parity sequences have been theoretically interpreted in the framework of the core particle coupling model. Evidence is presented for a shape change from collective prolate to non-collective oblate above the Jπ=39/2J^{\pi} = 39/2^{-} (8011 keV) level and for a smooth termination of the negative-parity band.Comment: 19 pages, 8 figures. Submitted to Phys. Rev.

    Enhanced Shot Noise in Tunneling through a Stack of Coupled Quantum Dots

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    We have investigated the noise properties of the tunneling current through vertically coupled self-assembled InAs quantum dots. We observe super-Poissonian shot noise at low temperatures. For increased temperature this effect is suppressed. The super-Poissonian noise is explained by capacitive coupling between different stacks of quantum dots
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