Sökning: "Nbn"

Visar resultat 1 - 5 av 73058 avhandlingar innehållade ordet Nbn.

  1. 1. NbN and NbTiN Hot Electron Bolometer THz Mixers

    Författare :Pourya Khosropanah; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; receiver noise; hot electron bolometer; superconducting detector; spiral antenna; NbTiN; submillimeter mixer; THz mixer; HEB; FTS; NbN; quasioptical receiver; heterodyne receiver; double slot antenna; twin slot antenna; Fourier Transform Spectrometer;

    Sammanfattning : The thesis reports the development of Hot Electron Bolometer (HEB) mixers for radio astronomy heterodyne receivers in THz frequency range. Part of this work is the fabrication of HEB devices, which are based on NbN or NbTiN superconducting thin films (≤5 nm). They are integrated with wideband spiral or double-slot planar antennas. LÄS MER

  3. 2. Thin Films and Component Technologies for Low-Noise Terahertz Electronics

    Författare :Dimitar Milkov Dochev; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; THz electronics; SIS; tunnel junctions; Nb3Al; NbN; thin film; hot electron bolometer; microwave circuits; superconductor; epitaxial film;

    Sammanfattning : This thesis deals with several distinct subjects such as thin film deposition, design, fabrication and characterization of components for low-noise THz electronics.High energy-gap superconducting materials are of specific importance for low-noise THz mixer applications. LÄS MER

  4. 3. Reactivity of Metal Clusters with Diatomic Molecules

    Författare :Lotta Holmgren; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nbn; cluster; reactivity; Rhn; NO; D2; CO; N2; laser vaporization; Wn; Nin; photoionization; time-of-flight mass spectrometer; ionization potential; Cun; O2; Vn;

    Sammanfattning : The reactivity of transition-metal clusters, in the approximate size range 10-60 atoms, with diatomic molecules has been investigated. A pulsed beam of neutral clusters is produced by a laser-vaporization source and passed through a low-pressure reaction cell containing the reactive gas. LÄS MER

  5. 4. Low and High Tc Bolometer Detectors for THz Frequencies

    Författare :Auréle Adam; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; direct detection; HEB; Terahertz technology; hot spot model; Sub-millimetre wave; NbN; YBaCuO; Heterodyne Mixer; hot electron bolometer;

    Sammanfattning : .... LÄS MER

  7. 5. Metal Cluster Reactivity. Adsorption of small molecules in biomolecular collisions

    Författare :Mats Andersson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; O2; CO; ionization potential; Con; Fen; NO; sticking probability; laser ionization; D2; Wn; Cun; Rhn; reaction probability; cluster; jellium model; Nbn; metal cluster reactivity; N2; time-of-flight mass spectrometry; Nin;

    Sammanfattning : Metal clusters can be characterized as the tiniest possible metal particles, containing only an easily counted number of atoms. In this work, reactions between metal clusters and diatomic molecules have been investigated. We have constructed an experimental set-up to produce and detect clusters, and to investigate their chemical reactivity. LÄS MER