Overview of ASDEX Upgrade results

Recent results from the ASDEX Upgrade experimental campaigns 2001 and 2002 are presented. An improved understanding of energy and particle transport emerges in terms of a 'critical gradient' model for the temperature gradients. Coupling this to particle diffusion explains most of the observed behaviour of the density profiles, in particular, the finding that strong central heating reduces the tendency for density profile peaking. Internal transport barriers (ITBs) with electron and ion temperatures in excess of 20 keV (but not simultaneously) have been achieved. By shaping the plasma, a regime with small type II edge localized modes (ELMs) has been established. Here, the maximum power deposited on the target plates was greatly reduced at constant average power. Also, an increase of the ELM frequency by injection of shallow pellets was demonstrated. ELM free operation is possible in the quiescent H-mode regime previously found in DIII-D which has also been established on ASDEX Upgrade. Regarding stability, a regime with benign neoclassical tearing modes (NTMs) was found. During electron cyclotron current drive (ECCD) stabilization of NTMs, βN could be increased well above the usual onset level without a reappearance of the NTM. Electron cyclotron resonance heating and ECCD have also been used to control the sawtooth repetition frequency at a moderate fraction of the total heating power. The inner wall of the ASDEX Upgrade vessel has increasingly been covered with tungsten without causing detrimental effects on the plasma performance. Regarding scenario integration, a scenario with a large fraction of noninductively driven current (≥50%), but without ITB has been established. It combines improved confinement (τE/τITER98 ≈ 1.2) and stability (βN ≤ 3.5) at high Greenwald fraction (ne/nGW ≈ 0.85) in steady state and with type II ELMy edge and would offer the possibility for long pulses with high fusion power at reduced current in ITER

Technische, analytische, organisatorische und rechtliche Massnahmen zur Verminderung der Klaerschlammbelastung mit relevanten organischen Schadstoffen: Positionen 1 und 2: Einleitung; Stoffberichte Abschlussberichte

Gegenstand der Arbeit war die Beurteilung der Relevanz von dreizehn organischen Stoffklassen fuer die landwirtschaftliche Verwertung von Klaerschlaemmen. Dazu wurden fuer alle Stoffe Daten ueber Produktionsmengen, Anwendungsmuster und Emissionen zusammengefasst. Phthalsaeureester und zinnorganische Verbindungen wurden zusaetzlich auf weitere umweltrelevante Eigenschaften untersucht. Fuer die Stoffgruppen der Phthalate, Zinnorganika, Tenside, PAK, Mineraloelkohlenwasserstoffe und Chlorparaffine wurden Massnahmen zur Minderung der Klaerschlammgehalte vorgeschlagen und hinsichtlich ihrer Wirksamkeit bewertet. Weiterhin wurden Klaerschlammzuschlagsstoffe auf ihre Bedeutung als Schadstoffquelle in Klaerschlaemmen untersucht. Aus der Vielzahl der in privaten Haushalten verwendeten Chemikalien konnte den Tensiden eine Bedeutung fuer den Klaerschlamm zugeordnet werden. Parallel zu den Literaturarbeiten wurden 53 Klaerschlammproben aus Anlagen aus dem ganzen Bundesgebiet entnommen, auf Phthalate, Zinnorganika, Tenside und PAK untersucht und unter verschiedenen Gesichtspunkten ausgewertet. Nach den vorliegenden Ergebnissen besitzt die Groesse der Klaeranlagen nur einen untergeordneten Einfluss auf die Klaerschlammgehalte, waehrend die Auslastung der Anlagen und die Schlammbehandlung die Konzentrationen in den Klaerschlaemmen beeinflussen. (orig.)Subject of the report has been the judgement of the relevance of thirteen groups of organic compounds to the utilization of sewage in agriculture. In this connection for all compounds data upon production, preferred use and related emissions have been collected. Additionally phthalate plasticizers and tin organic compounds have been examined for other characteristics, having an impact on the environment. For the following groups of organic compounds, measures to reduce their concentration in sewage sludge have been proposed and judged for their effectiveness: phthalate plasticizers, tin organic compounds, tensides, PAH, mineral oil hydrocarbons and chlorinated paraffines. Furthermore additives to sewage sludge have been examined for their importance as sources of pollutants in the same. From the wide variety of chemicals used in households, tensides have been assigned to be an important factor for the sewage sludge. In parallel to papers from literature, 53 samples of sewage sludge have been taken from different plants all over the Federal Republic of Germany and analyzed for phthalate plasticizers, tin organic compounds, tensides and PAH and examined under various aspects. According to the results available, the size of the sewage sludge plant has a minor influence on the pollutants in the sewage sludge, whereas the degree of capacity utilization of the plant as well as the treatment of the sludge are influencing the concentration of the pollutants in the sewage sludge. (orig.)Also published as UBA-Texte 35/98SIGLEAvailable from TIB Hannover: RN 8908(98-037,1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekUmweltbundesamt, Berlin (Germany); Bundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)DEGerman