Change search
Refine search result
1 - 26 of 26
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Bentell, J.
    et al.
    Wennekes, F.
    Salomonsson, F.
    Hammar, M.
    Streubel, K.
    Characterisation of n-InP/n-GaAs Wafer Fused Heterojunctions1999In: Physica scripta. T, ISSN 0281-1847, Vol. 79, p. 206-208Article in journal (Refereed)
    Abstract [en]

    We have investigated the properties of wafer-fused Si-doped isotype hetero-junctions between GaAs and InP. Current/voltage measurements were conducted to study the influence of the doping concentrations on each side of the interface on the electrical conductivity. An almost ohmic behavior with a very low series resistance was obtained for the highest examined doping level on the GaAs side, whereas the doping concentration on the InP side was found to be of little significance. Fusion at different temperatures showed that the conductivity degrades significantly below 500°C, although mechanically stable junctions were obtained also at temperatures as low as 305°C. Secondary ion mass spectroscopy measurements showed no redistribution of Si, but indicated the presence of small amounts of C and Fe impurities at the interface.

  • 2. Coad, J. P.
    et al.
    Hole, D. E.
    Rubel, Marek J.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Widdowson, A.
    Vince, J.
    Deposition results from rotating collector diagnostics in JET2009In: Physica scripta. T, ISSN 0281-1847, Vol. T138, p. 014023-Article in journal (Refereed)
    Abstract [en]

    Rotating collectors (RC) were installed in JET during the period 2005-2007, each providing a time-resolved deposition pattern on the surface of a rotating silicon disc, which could be analysed once retrieved from the vessel. This paper reports results from the silicon disc removed from the RC located under the load-bearing septum replacement plate in JET in 2007. Nuclear reaction analysis results of the deposits on the disc have been correlated directly with the pattern of erosion and deposition observed by the quartz microbalance (QMB) located in an equivalent position. The thickest film in the time-resolved region (i.e. deposited in similar to 60 pulses) was similar to 250 nm, and the Be/C ratio was generally found to be 0.1 or lower, with two regions where the ratio rose to 0.2. The deposition observed with the QMB appears to be about a factor of four less.

  • 3. Danielsson, Erik
    et al.
    Breitholtz, Bo
    Zetterling, Carl-Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Östling, Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Simulation Study of on-state Losses as Function of Carrier Life-time for a GaN/SiC High Power HBT Design1999In: Physica scripta. T, ISSN 0281-1847, Vol. 79, p. 290-293Article in journal (Refereed)
    Abstract [en]

    SiC has several properties that makes it more suitable than silicon for high power devices. One problem with SiC bipolar devices is the short carrier life times, and this problem becomes more severe when designing devices for high voltage applications since the dimensions are larger. This work investigates how the Shockley-Read-Hall lifetime influences the on-state characteristics of a HBT or BJT switch in 4H-SiC. The on-state characteristics were simulated with varying SRH lifetimes in the base and drift region. Comparisons were made at 100 A/cm2 collector current density, Jc, and at the base current density, JB, where the total on-state power loss of the design is at minimum. The SRH lifetime in the drift region is the dominant parameter for on-state performance, whereas the SRH lifetime in the base is of much less importance. The simulations showed that to reach an acceptable JC/JB-ratio of 100 at power minimum a SRH lifetime of at least 100 ÎŒs in the drift region was needed for the HBT design. This lifetime is far from the experimental values reported for 4H-SiC. The advantages of the heterojunction in comparison to ordinary BJTs decreases with shorter SRH lifetimes, but an improvement could always be seen.

  • 4. De Temmerman, G.
    et al.
    Doerner, R. P.
    John, P.
    Lisgo, S.
    Litnovsky, A.
    Marot, L.
    Porro, S.
    Petersson, P.
    Rubel, Marek J.
    Rudakov, D. L.
    Van Rooij, G.
    Westerhout, J.
    Wilson, J. I. B.
    Interactions of diamond surfaces with fusion relevant plasmas2009In: Physica scripta. T, ISSN 0281-1847, Vol. T138, p. 014013-Article in journal (Refereed)
    Abstract [en]

    The outstanding thermal properties of diamond and its low reactivity towards hydrogen may make it an attractive plasma-facing material for fusion and calls for a proper evaluation of its behaviour under exposure to fusion-relevant plasma conditions. Micro and nanocrystalline diamond layers, deposited on Mo and Si substrates by hot filament chemical vapour deposition (CVD), have been exposed both in tokamaks and in linear plasma devices to measure the erosion rate of diamond and study the modification of the surface properties induced by particle bombardment. Experiments in Pilot-PSI and PISCES-B have shown that the sputtering yield of diamond (both physical and chemical) was a factor of 2 lower than that of graphite. Exposure to detached plasma conditions in the DIII-D tokamak have evidenced a strong resistance of diamond against erosion under those conditions.

  • 5.
    Domeij, Martin
    et al.
    KTH, Superseded Departments, Electronics.
    Breitholtz, Bo
    KTH, Superseded Departments, Electronics.
    Linnros, Jan
    KTH, Superseded Departments, Electronics.
    Ostling, Mikael
    KTH, Superseded Departments, Electronics.
    Avalanche injection in high voltage Si PiN diodes1997In: Physica scripta. T, ISSN 0281-1847, Vol. T69, p. 134-137Article in journal (Refereed)
    Abstract [en]

    An experimental technique using optical excitation by a YAG laser pulse for studying avalanche injection in power devices is demonstrated This technique enables the creation of high uniform excess carrier concentrations in an optically defined device volume, involving very little heating. A method for determining the onset of avalanche multiplication, by studying the time integral of the reverse recovery current, is proposed. A PiN diode is observed to turn off from avalanching at a dissipated power density of more than 200 kW/cm(2).

  • 6. Erman, P.
    et al.
    Karawajczyk, A.
    Rachlew-Källne, Elisabeth
    KTH, Superseded Departments, Physics.
    Riu, J. R. I.
    Stankiewicz, M.
    Franzen, K. Y.
    Moen, A. W.
    Veseth, L.
    Non Franck-Condon effects in photoionization of molecular oxygen2000In: Physica scripta. T, ISSN 0281-1847, Vol. 62, no 4, p. 294-300Article in journal (Refereed)
    Abstract [en]

    We present a theoretical and experimental analysis of non Franck-Condon effects in photoionization to the b (4)Sigma(g)(-), state of O-2(+). Experimentally, by dispersing the synchrotron radiation induced O-2(+) b (4)Sigma(g)(-) a (IIu)-I-4 fluorescence we derive the b (4)Sigma(g)(-), State vibrational branching ratios in the excitation energy range 21-34 eV. The vibrational branching ratios reveal features in the region 21-28 eV indicating strong non Franck-Condon effects. The experimental results have been analysed by computing ab initio the vibrational population branching ratios using a many-body perturbation method. Additionally the autoionizing neutral states existing in this energy region have been studied. We have computed the energies of the valence states up to an energy of 30 eV their transition moments for excitations from the ground state, and autoionization rates. Our calculations show, that strong non Franck-Condon effects recorded in the branching ratio spectrum (below 25 eV) are actually caused by the narrow 3 sigma(g) --> sigma(u) shape resonance, and its coupling to the 1 pi(u) --> pi(g) channel.

  • 7. FANT, B
    et al.
    Cederwall, Bo
    CEDERKALL, J
    NORLIN, LO
    WYSS, R
    FALLON, P
    BEAUSANG, CW
    BUTLER, PA
    ROBERTS, JW
    BRUCE, AM
    CULLEN, DM
    MULLINS, SM
    POYNTER, RJ
    WADSWORTH, R
    RILEY, MA
    KORTEN, W
    PIIPARINEN, MJ
    SHELL STRUCTURE AND SHAPE COEXISTENCE IN PB-1951995In: Physica scripta. T, ISSN 0281-1847, Vol. T56, p. 245-248Article in journal (Refereed)
    Abstract [en]

    Pb-195 was investigated utilizing the reactions Dy-164(S-36, 5n)Pb-195 and Dy-164(S-34, 3n)Pb-195 at beam energies of 170 and 160MeV respectively. Two new dipole bands which feed into the yrast 25/2(+) state, were found in Pb-195. The connection between the bands and the spherical states was established and thus spins and energies of the involved collective states were determined. The deformation is understood as mainly due to excitations of protons across the Z = 82 shell gap. The observed backbends are interpreted as alignment of i(13/2) neutrons.

  • 8.
    Han, Shunhui
    et al.
    KTH, Superseded Departments, Physics.
    Andersson, Magnus
    KTH, Superseded Departments, Physics.
    The upper critical-field of pb doped BI-SR-CA-CU-O compounds1991In: Physica scripta. T, ISSN 0281-1847, Vol. 44, no 11, p. 69-70Article in journal (Refereed)
    Abstract [en]

    The upper critical field H(c2) of four Bi-(Pb)-Sr-Ca-Cu-O superconductors with the 110 K phase has been measured as a function of temperature. H(c2) exhibited a (T(c) - T)alpha-temperature dependence with alpha > 1 f two impure samples, but showed a linear temperature dependence for the purest sample, which is not expected according to current theories and other experiments.

  • 9. Huber, A.
    et al.
    Mayer, M.
    Philipps, V.
    Pospieszczyk, A.
    Ohgo, T.
    Rubel, Marek J.
    KTH, Superseded Departments, Alfvén Laboratory.
    Schweer, B.
    Sergienko, G.
    Tanabe, T.
    In-situ measurement of trapped hydrogen by laser desorption in TEXTOR-942001In: Physica scripta. T, ISSN 0281-1847, Vol. T94, p. 102-105Article in journal (Refereed)
    Abstract [en]

    First measurements on laser induced desorption of deuterium incorporated in a boron layer formed by plasma chemical vapor deposition on tungsten and graphite limiter surfaces have been performed. A ruby laser (lambda = 694 nm) with maximum energy of 50 J and a pulse length of about 0.5 ms was used as a heat source. The desorbed deuterium was detected by mass spectroscopy and total pressure analysis in the residual gas. The amount of desorbed deuterium is about 10(17) D atoms cm(-2). The majority of the deuterium is released during the first laser pulse. The limiter heads were investigated post-mortem by means of ion beam analysis to determine the spatial distribution of boron and deuterium and to investigate the effect of the laser pulse on the release of deuterium and sublimation of boron in the laser spot. All the deuterium has been released by the laser pulse. The boron is sublimated partly from the graphite and removed nearly completely from the tungsten surface.

  • 10.
    Ivanova, Darya
    et al.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Rubel, Marek J.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Philipps, V.
    Institute for Energy Research, Forschungszentrum Jülich, Association EURATOM-FZJ, Germany.
    Freisinger, M.
    Institute for Energy Research, Forschungszentrum Jülich, Association EURATOM-FZJ, Germany.
    Huang, Z.
    KTH, School of Electrical Engineering (EES), Centres, Alfvén Laboratory Centre for Space and Fusion Plasma Physics.
    Penkalla, H.
    Institute for Energy Research, Forschungszentrum Jülich, Association EURATOM-FZJ, Germany.
    Schweer, B.
    Institute for Energy Research, Forschungszentrum Jülich, Association EURATOM-FZJ, Germany.
    Sergienko, G.
    Institute for Energy Research, Forschungszentrum Jülich, Association EURATOM-FZJ, Germany.
    Sundelin, Per
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Wessel, E.
    Institute for Energy Research, Forschungszentrum Jülich, Association EURATOM-FZJ, Germany.
    Survey of dust formed in the TEXTOR tokamak: structure and fuel retention2009In: Physica scripta. T, ISSN 0281-1847, Vol. T138, p. 014025-Article in journal (Refereed)
    Abstract [en]

    A detailed survey of erosion and deposition on plasma-facing components was performed in the TEXTOR tokamak. Co-deposits and dust particles were collected from graphite limiters and from several locations on the Inconel liner. The total amount of dust (loose material), originating mainly from carbon-rich co-deposits detached from the limiters and the liner, was around 2 g, with sizes from 0.1 mu m to 1 mm. The morphology and fuel retention was determined using microscopy methods, ion beam analysis and thermal desorption spectrometry. The study revealed differences in structure and fuel content between deposits from the toroidal and main poloidal limiters. There were also splashes, up to 1 mm in diameter, of molten metal (mainly nickel) on the toroidal limiters. Issues of the dust conversion factor (erosion-to-dust) are addressed and a comparison with results of previous dust surveys at TEXTOR is also briefly presented.

  • 11.
    KARLSSON, Ulf O
    et al.
    KTH, School of Information and Communication Technology (ICT).
    HANSSON, GV
    PERSSON, PES
    FLODSTROM, SA
    ELFARRASH, AH
    SURFACE-STATE AND DIRECT TRANSITIONS ON AL (111) INVESTIGATED WITH ANGLE-RESOLVED PHOTOELECTRON-SPECTROSCOPY1985In: Physica scripta. T, ISSN 0281-1847, Vol. 32, no 1, p. 39-42Article in journal (Refereed)
  • 12. Khotyaintsev, Y.
    et al.
    Ivchenko, Nickolay V.
    KTH, Superseded Departments, Alfvén Laboratory.
    Stasiewicz, K.
    Berthomier, M.
    Electron energization by Alfven waves: Freja and sounding rocket observations2000In: Physica scripta. T, ISSN 0281-1847, Vol. T84, p. 151-153Article in journal (Refereed)
    Abstract [en]

    Recent sounding rockets observations highlight some space-time ambiguities in phenomena taking place in the auroral ionosphere, previously observed by the Freja spacecraft. Field aligned electron populations with energies from a few tens of eV to a few keV streaming through cold background plasma are usually observed in the auroral zone in association with strongly nonlinear electromagnetic perturbations. Simultaneous observations of bursty Langmuir emissions indicate the unstable character of these plasma distributions. A detailed analysis shows that the electromagnetic perturbations take the form of quasi-stationary nonlinear spatial structures related to inertial Alfven waves. We suggest that inhomogeneous altitude distribution of the parallel electric field of these structures due to ionospheric density gradientis responsible for the observed electron distributions.

  • 13. Kreter, A.
    et al.
    Baldwin, M. J.
    Doerner, R. P.
    Nishijima, D.
    Petersson, P.
    Pospieszczyk, A.
    Rubel, Marek J.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Umstadter, K.
    Fuel retention in carbon materials under ITER-relevant mixed species plasma conditions2009In: Physica scripta. T, ISSN 0281-1847, Vol. T138, p. 014012-Article in journal (Refereed)
    Abstract [en]

    Samples of CFC NB41 and fine-grain graphite ATJ have been exposed to PISCES plasmas containing (i) pure deuterium, (ii) deuterium and beryllium, (iii) deuterium, beryllium and helium, and (iv) deuterium, beryllium and argon. Thermal desorption spectrometry (TDS) and nuclear reaction analysis (NRA) have been used to measure the amount and distribution of retained deuterium in the samples. For the case of pure deuterium plasma, parametric studies of deuterium retention in NB41 have been done with variations of the incident deuterium fluence (Phi = 1 x 10(25)-5 x 10(26) m(-2)), ion energy (E-i = 20-120 eV) and sample surface temperature (T-s = 370-820 K). It has been found, that for T-s = 470K the retention scales as Phi(0.35). For T-s = 820K the retention saturates at a level of similar to 10(21) Dm(-2). The retention increases with E-i and drops with higher T-s. At T-s = 720 K, the beryllium seeding results in a building of a protective beryllium carbide layer, which appears to prevent the in-bulk diffusion of deuterium, thus reducing the retention. Admixture of Ar and, in the case of low E-i, He leads to a significant reduction of the retention.

  • 14. Krlin, L.
    et al.
    Stockel, J.
    Svoboda, V.
    Tendler, Michael
    KTH, Superseded Departments, Alfvén Laboratory.
    Stochastic (E x B) diffusion of ions in a spatially periodical potential field2000In: Physica scripta. T, ISSN 0281-1847, Vol. T84, p. 221-224Article in journal (Refereed)
    Abstract [en]

    In this contribution, the stochastic (E x B) motion of ions in a homogeneous magnetic field and in a spatially periodical electrostatic potential is discussed. This approach is used for the simulation of ion diffusion in potential structures formed at the boundary plasma in tokamaks. Nonintegrability of the system causes the spatial diffusion of ions. Depending on the choice of parameters, this diffusion has either the usual random-walk character, or appears, for sufficiently strong nonlinearity, in the form of Levy walks. The diffusion coefficient is sufficiently high for heavy impurities. Possible further applications are mentioned.

  • 15. Linke, J.
    et al.
    Rubel, Marek J.
    KTH, Superseded Departments, Alfvén Laboratory.
    Malmberg, J. A.
    Drake, James R.
    KTH, Superseded Departments, Alfvén Laboratory.
    Duwe, R.
    Penkalla, H. J.
    Rodig, M.
    Wessel, E.
    Carbon particles emission, brittle destruction and co-deposit formation: Experience from electron beam experiments and controlled fusion devices2001In: Physica scripta. T, ISSN 0281-1847, Vol. T91, p. 36-42Article in journal (Refereed)
  • 16. MAKELA, E
    et al.
    VIRTANEN, A
    JULIN, R
    JUUTINEN, S
    PIIPARINEN, M
    TORMANEN, S
    SEWERYNIAK, D
    ATAC, A
    CEDERWALL, BO
    FAHLANDER, C
    IDEGUCHI, E
    JOHNSON, A
    KARCZMARCZYK, W
    KOWNACKI, J
    MITARAI, S
    NORLIN, LO
    NYBERG, J
    SCHUBART, R
    SLETTEN, G
    COEXISTENCE OF COLLECTIVE AND QUASI-PARTICLE STRUCTURES IN SN-106,SN-108 NUCLEI1995In: Physica scripta. T, ISSN 0281-1847, Vol. T56, p. 280-283Article in journal (Refereed)
    Abstract [en]

    New revels in two neutron deficient nuclei Sn-106.108 have been found by using the Nordball detector array extended with the arrangements of charged particle and neutron detectors. The excited structures are discussed in terms of collectivity and the shell model. The systematical behaviour of the states in Sn isotopes is studied in the mass range of A = 104-118.

  • 17. Matthews, G. F.
    et al.
    Edwards, P.
    Greuner, H.
    Loving, A.
    Maier, H.
    Mertens, Ph
    Philipps, V.
    Riccardo, V.
    Rubel, Marek J.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Ruset, C.
    Scmidt, A.
    Villedieu, E.
    Current status of the JET ITER-like Wall Project2009In: Physica scripta. T, ISSN 0281-1847, Vol. T138, p. 014030-Article in journal (Refereed)
    Abstract [en]

    This paper presents an overview of the status and relevant technical issues for the ITER-like Wall Project with emphasis on progress since the 11th International Workshop on Plasma-Facing Materials and Components for Fusion Applications.

  • 18.
    Ohlsson, Tommy
    KTH, Superseded Departments, Physics.
    Neutrino oscillations in matter and their applications2001In: Physica scripta. T, ISSN 0281-1847, Vol. T93, p. 18-25Article in journal (Refereed)
    Abstract [en]

    In this paper, an introduction to the evolution operator method for three flavor neutrino oscillations in matter based on the Cayley-Hamilton formalism is presented as well as some its theoretical and experimental applications.

  • 19. Plashkevych, O.
    et al.
    Snis, A.
    Yang, L.
    Ågren, Hans
    KTH, Superseded Departments, Biotechnology.
    Matar, S. F.
    Near-edge X-ray absorption spectra of carbon-nitride molecules and solids2001In: Physica scripta. T, ISSN 0281-1847, Vol. 63, no 1, p. 70-86Article in journal (Refereed)
    Abstract [en]

    Near-edge X-ray absorption fine structure spectra have been calculated for different carbon-nitrogen molecules, clusters and solids. The compounds investigated are used to model the chemical bonding in carbon nitride thin films. The molecular and cluster spectra are calculated employing the static exchange ab initio technique, while the solid state calculations are performed with the density functional full potential augmented plane wave method.

  • 20.
    Qi, Chong
    et al.
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Blomqvist, Jan
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Bäck, Torbjörn
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Cederwall, Bo
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Johnson, Arne
    KTH, School of Engineering Sciences (SCI), Physics.
    Liotta, Roberto
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Wyss, Ramon
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Coherence features of the spin-aligned neutron-proton pair coupling scheme2012In: Physica scripta. T, ISSN 0281-1847, Vol. T150, p. 014031-Article in journal (Refereed)
    Abstract [en]

    The seniority scheme has been shown to be extremely useful for the classification of nuclear states in semi-magic nuclei. The neutron-proton (np) correlation breaks the seniority symmetry in a major way. As a result, the corresponding wave function is a mixture of many components with different seniority quantum numbers. In this paper, we show that the np interaction may favor a new kind of coupling in N = Z nuclei, i.e. the so-called isoscalar spin-aligned np pair mode. Shell model calculations reveal that the ground and low-lying yrast states of the N = Z nuclei Pd-92 and Cd-96 may be mainly built upon such spin-aligned np pairs, each carrying the maximum angular momentum J = 9 allowed by the shell 0 g(9/2) which is dominant in this nuclear region.

  • 21. Stasiewicz, K.
    et al.
    Lundin, R.
    Marklund, Göran T.
    KTH, Superseded Departments, Alfvén Laboratory.
    Stochastic ion heating by orbit chaotization on electrostatic waves and nonlinear structures2000In: Physica scripta. T, ISSN 0281-1847, Vol. T84, p. 60-63Article in journal (Refereed)
    Abstract [en]

    We demonstrate that satellite observations of intense transverse ion energization could be explained by stochastic ion heating on short perpendicular wavelength electrostatic waves and structures produced by the decay of dispersive Alfven waves (DAW) This mechanism is related to the chaotization of ion orbits which leads to strong stochastic heating when the electric field gradient fulfills the inequality partial derivative E-x/partial derivative x > Omega B-0 (here Omega is the ion gyrofrequency and B-0 is the ambient magnetic field). We also show that the energy sourer for this process is provided from dissipation of the Poynting flux of DAW. which appear to form an energy cascade from large scales lambda(perpendicular to) similar to kilometers down to lambda(perpendicular to) similar to 50 m where the dissipation through the ion heating is observed.

  • 22. Tashenov, S.
    et al.
    Bäck, Torbjörn
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Barday, R.
    Cederwall, Bo
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Enders, J.
    Khaplanov, Anton
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Fritzsche, Y.
    Schässburger, Kai-Uwe
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Surzhykov, A.
    Yerokhin, V. A.
    Observation of the spin-orbit interaction in bremsstrahlung2013In: Physica scripta. T, ISSN 0281-1847, Vol. T156, p. 014071-Article in journal (Refereed)
    Abstract [en]

    The effects of the spin-orbit interaction are pronounced for an electron scattered in a Coulomb field of the nucleus. They cause the electron scattering plane to turn or precess as the electron moves. This precession is visible through linear polarization of bremsstrahlung. The first experiment to observe it is described in this contribution.

  • 23.
    Weckmann, Armin
    et al.
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Petersson, Per
    Rubel, Marek
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Fortuna-Zalesna, Elzbieta
    Zielinski, Witold
    Romelczyk, Barbara
    Grigore, Eduard
    Ruset, Cristian
    Kreter, Arkadi
    Ageing of structural materials in tokamaks: TEXTOR liner study2017In: Physica scripta. T, ISSN 0281-1847, Vol. T170, article id 014053Article in journal (Refereed)
    Abstract [en]

    After the final shut-down of the tokamak TEXTOR, all of its machine parts became accessible for comprehensive studies. This unique chance enabled the study of the Inconel 625 liner by a wide range of methods. The aim was to evaluate eventual alteration of surface and bulk characteristics from recessed wall elements that may influence the machine performance. The surface was covered with stratified layers consisting mainly of boron, carbon, oxygen, and in some cases also silicon. Wall conditioning and limiter materials hence predominantly define deposition on the liner. Deposited layers on recessed wall elements reach micrometre thickness within decades, peel off and may contribute to the dust inventory in tokamaks. Fuel retention was about 4 at% of the overall layers, with no evidence for diffusion into the Inconel substrate. Inconel 625 retained its mechanical strength despite 26 years of cyclic heating, stresses and particle bombardment.

  • 24. Widdowson, A.
    et al.
    Brezinsek, S.
    Coad, J. P.
    Hole, D. E.
    Likonen, J.
    Philipps, V.
    Rubel, Marek J.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Stamp, M. F.
    An overview of erosion-deposition studies for the JET Mk II high delta divertor2009In: Physica scripta. T, ISSN 0281-1847, Vol. T138, p. 014005-Article in journal (Refereed)
    Abstract [en]

    Post-mortem analyses of tiles removed from the JET MkII HD divertor in 2007 are presented. The results indicate an increase in deposition at the outer plasma-shadowed region of the divertor, not seen prior to 2004 and indicate a shift away from the asymmetric picture of net deposition at the inner divertor compared with no overall deposition or erosion at the outer divertor. Surface analysis of the inner and outer vertical divertor tiles is largely the same as observed previously; however, a notable increase in Be composition on the inner and outer floor tiles is observed. An attempt has been made to correlate these data with campaign-averaged plasma configurations and spectroscopy results. While some changes in deposition/erosion characteristics can be explained, further detailed analysis of diagnostics and especially of time-resolved data, such as from rotating collector and quartz microbalance diagnostics, is required.

  • 25. Wienhold, P.
    et al.
    Rubel, Marek J.
    KTH, Superseded Departments, Alfvén Laboratory.
    Mayer, M.
    Hildebrandt, D.
    Schneider, W.
    Kirschner, A.
    Deposition and erosion in local shadow regions of TEXTOR-942001In: Physica scripta. T, ISSN 0281-1847, Vol. T94, p. 141-145Article in journal (Refereed)
    Abstract [en]

    Carbon erosion and deposition were investigated on the surface of a flat target covered with an a-C:H film and exposed for 197 s in the SOL of TEXTOR-94. The target was declined by 20 degrees with respect to the toroidal direction and partly protected by an aluminum (3 mm) plate which created an 8 mm wide local shadow. Thickness changes were measured by colorimetry after each plasma discharge. Carbon is eroded from surface areas near the plasma edge (LCFS +1 cm) and transported into the local shadow regions. Accumulation rates up to approximate to 7nm/s were found. The erosion in the local shadow regions (about - 0.1 nm/s) is due to charge exchange neutrals. The observations are confirmed by ion beam analyses and by preliminary calculations with the B2-EIRENE and ERO-TEXTOR code.

  • 26.
    Zetterling, Carl-Mikael
    et al.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Östling, Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Thermal oxidation of n- and p-type 6H-silicon carbide1994In: Physica scripta. T, ISSN 0281-1847, Vol. T54, p. 291-294Article in journal (Refereed)
1 - 26 of 26
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf