Developement and use of far infrared lasers in studies of collective electron density fluctuations in a tokamak plasma by Thomson scattering

The measurement of the tokamak plasma ion temperature can be obtained by collective Thomson scattering. This method requires a far infrared laser to achieve useful spatial resolution for typical tokamak plasma parameters. The very low Thomson scattering cross section (10-28 m2) implies the use of a pulsed far infrared laser with 1 MW power and 1 µs pulse duration. With the best technology of far infrared heterodyne receivers available today, with a noise equivalent power (NEP) below 10-18 W/Hz, it should be possible to measure the ion temperature with 20 % precision. This thesis describes the development of a far infrared laser and a detection system to prove the feasibility of the ion temperature measurement by collective Thomson scattering on the TCA tokamak. This tokamak is situated at the Centre de Recherches en Physique des Plasmas (CRPP) of the Ecole Polytechnique Fédérale in Lausanne. The aim was to observe a scattered signal from the plasma and to obtain the required practical knowledge for the design of a large Thomson scattering system to measure the ion temperature in TCA. For the experiment, an optically pumped D2O laser is used to produce pulses of 1 µs duration and 150 kW of power, at the far infrared wavelength of 385 µm. The scattered signal is observed with a heterodyne Schottky diode detection system using a quasi continuous CD3Cl far infrared laser as local oscillator. The scattered spectrum is resolved through a multichannel S band microwave filter bank, after which the signals are integrated and digitized. Although the laser power is not sufficient to permit an instantaneous ion temperature measurement, a scattered signal correlated with the presence of the plasma was observed when averaging over ten tokamak discharges. It has been found that perturbations from microturbulence in the plasma are not significant within the useful bandwidth of the scattered spectrum. Hence an increase in the available far infrared laser power and a better sensitivity of the detection system should be sufficient to allow for a single discharge ion temperature measurement. The experiment also showed the necessity to reduce the NEP of the detection system, which currently presents an excessively high mixer conversion loss. This is being improved for the future installation of a multi-megawatt far infrared laser. With this new laser it should be possible to obtain the first direct measurement of the tokamak ion temperature by collective Thomson scattering on a tokamak

En forståelse av Red Bulls merkeassosiasjoner gjennom sponsing

Bedrifter ser stadig etter gode virkemidler for å skape merkekjenneskap. Sponsing er et markedsføringsvirkemiddel som blir stadig mer brukt i dagens marked. Ulike aktører går inn for å sponse alt fra eventer, klubber og festivaler, til enkelte idrettsutøvere i håp om å skape merkekjennskap og positive assosiasjoner blant ulike målgrupper. En av de store aktørene innenfor sponsing i Norge er Red Bull. Red Bull er en av verdens største leverandører av energidrikk, som blant annet også eier et Formel 1-lag, 5 fotballklubber og et ishockeylag. Vi hadde et ønske om å utforske temaet sponsing og merkevaren Red Bull, og valgte på bakgrunn av dette å se på hvordan deres sponsorvirksomhet brukes som et markedsføringsvirkemiddel. Vi kom dermed frem til problemstillingen; «Hvordan bruker Red Bull sin sponsorvirksomhet for å forsterke og tilegne seg nye merkeassosiasjoner?» For å belyse denne problemstillingen har vi funnet frem relevant teoretisk rammeverk. Samtidig har vi gjennomført tre dybdeintervjuer som har gitt oss en dypere innsikt når det kommer til temaet. I denne studien har vi kommet fram til at Red Bull sin sponsorvirksomhet aktivt søker mot å sponse individuelle idrettsutøvere for å tilegne seg deres assosiasjoner. På veien hit har vi kommet frem til at det er noen generelle faktorer som bør ligge til grunn for en assosiasjonsoverføring, samt at klassisk betinging gir en forklaring på hvordan merkevaren og utøveren kan kobles sammen. Samsvar blir trukket frem som en viktig faktor når det kommer til responsen på et sponsorat. Når utøveren oppleves som like eller har egenskaper som passer til merkevaren, finner man gjerne et logisk samsvar. Et logisk samsvar vil gjøre at responsen fra kunder eller publikum blir bedre. Vi har også kommet fram til at samsvar er noe som burde ligge til grunn for et sponsorat, men at aktivering i større grad er viktig i et sponsorat. Gjennom våre funn har vi kunnet konkludere med at Red Bull har forsterket sine eksisterende, og tilegnet seg nye, merkeassosiasjoner. Det må allikevel påpekes at denne studien har svakheter som påvirker reliabiliteten, og vi kan derfor ikke generalisere resultatene

Petrography, structure and metamorphism of mélange rocks below the Jotun Nappe in Stølsheimen, Central South Norway

The Caledonian mélange unit of South Norway is a unit that has largely been overlooked in previously studies of the Caledonides. The mélange consists of Alpine type metaperidotite bodies now found as serpentinites, talc and serpentine conglomerate. The ultramafics are set in a metasedimentary matrix, together with some minor meta-basalt/gabbro units. The mélange has recently been identified as a separate tectonic unit and is believed to be remnants of a hyperextended margin, and challenges the traditional interpretation of the Scandinavian orogen. The unit is positioned structurally below the crystalline nappes previously assigned to the Middle Allochthon. Recent works have recognized that the Allochthone units of the Caledonian orogen have a much more complex relationship than previously believed. This thesis investigates the mélange unit at Selhamar, Stølsheimen in search of a more detailed description of the host rocks surrounding the ultramafic bodies in term of petrography, structures and metamorphism. The ultramafic bodies in the study area of this thesis are described in detail by Enger (work in progress). In Stølsheimen the mélange unit lies structurally between the Lower and Upper Bergsdalen nappes, underneath the Jotun Nappe Complex. The metasediments in the study area consists of metasandstone, metapelites and garnet micaschist, and are found together with some minor (garnet) amphibolite outcrops and slivers of gneissic rocks from the Upper Bergsdalen Nappe. The metasediments was exposed to upper greenschist to lower amphibolite metamorphic conditions (515-525oC and 7100-7450bars) during the Caledonian orogen. This is based on thermobarometric modelling by the use of the Theriak-Domino program suite together with bulk rock composition. The study area is dominated by top-to-the-NW shear direction and large scale folding, corresponding to Caledonian extension