Sökning: "impact ionization"

Visar resultat 1 - 5 av 43 avhandlingar innehållade orden impact ionization.

  1. 1. First Principles Calculations of Electron Transport and Structural Damage by Intense Irradiation

    Författare :Carlos Ortiz; Olle Eriksson; Mattias Klintenberg; Richard A. London; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Condense matter theory; electronic structure; quasiparticles; GW theory; molecular dynamics; Boltzmann transport; electron transport; impact ionization; structural damage; dielectric response; structural biology; radiation detectors; scintillators; positron emission tommography; Electronic structure; Elektronstruktur; Semiconductor physics; Halvledarfysik; Biological physics; Biologisk fysik; Critical phenomena phase transitions ; Kritiska fenomen fasövergångar ; Functional materials; Funktionella material; Materiefysik; Physics of Matter;

    Sammanfattning : First principle electronic structure theory is used to describe the effect of crystal binding on radiation detectors, electron transport properties, and structural damage induced by intense irradiation. A large database containing general electronic structure results to which data mining algorithms can be applied in the search for new functional materials, a case study is presented for scintillator detector materials. LÄS MER

  3. 2. Electrophoretic focusing in microchannels combined with mass spectrometry : Applications on amyloid beta peptides

    Författare :Saara Mikkonen; Åsa Emmer; Johan Jacksén; Tapio Kotiaho; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; amyloid beta; computer simulation; electrophoresis; electrospray ionization; isoelectric focusing; isotachophoresis; MALDI; mass spectrometry; microchannel; microchip; nano-electrospray ionization; preconcentration; separation; Kemi; Chemistry;

    Sammanfattning : Analysis of low-abundance components in small samples remains a challenge within bioanalytical chemistry, and new techniques for sample pretreatments followed by sensitive and informative detection are required. In this thesis, procedures for preconcentration and separation of proteins and peptides in open microchannels fabricated on silicon microchips are presented. LÄS MER

  4. 3. Measurements of the 234U(n,f) Reaction with a Frisch-Grid Ionization Chamber up to En=5 MeV

    Författare :Ali Al-Adili; Pomp Stephan; Franz-Josef Hambsch; Michael Österlund; Talou Patrick; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fission; U-234; Neutron; Uranium; Resonance; Ionization Chamber; Frisch-grid; Fysik med inriktning mot tillämpad kärnfysik; Physics with specialization in Applied Nuclear Physics;

    Sammanfattning : This study on the neutron-induced fission of 234U was carried out at the 7 MV Van de Graaff accelerator of IRMM in Belgium. A Twin Frisch-Grid Ionization Chamber (TFGIC) was used to study 234U(n,f) between En = 0.2 and 5.0 MeV. LÄS MER

  5. 4. Recombination and ionization of astrophysically abundant ions

    Författare :Michael Jr. Fogle; Reinhold Schuch; Daniel Savin; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atomic data; plasma; Atomic and molecular physics; Atom- och molekylfysik;

    Sammanfattning : The electron-ion recombination and electron-impact ionization of several astrophysically abundant C, N, O, and Ni ions have been investigated using the synchrotron storage ring CRYRING. The recombination rate coefficients predominanty used in the analyses of emission line spectra and for ionization balance calculations are determined from isoelectronic fits and extrapolations of theoretical and limited experimental results available from the literature. LÄS MER

  7. 5. Electron impact dissociation of molecular ions at CRYRING

    Författare :Ahmed Al-Khalili; Ronald A Phaneuf; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; fysik;

    Sammanfattning : In this thesis, the electron impact dissociation of molecular ions has been studied using the ion storage ring CRYRING at Manne Siegbahn Laboratory in Stockholm, Sweden. The electron impact dissociation of molecular ions occurs via many processes, which lead to different charge states of the product fragments. LÄS MER