Obiettivo The work on toroidal magnetic confinement, on which IPP has concentrated in the context of the European programme, is to be continued with the requisite technical developments. In this connection, IPP and KfK are cooperating in a development partnership in which IPP is responsible for plasma-physics problems and KfK deals with those relating to fusion technology.In many stellarators, envisaged as fusion devices, any alpha particle which ever gets reflected is collisionlessly lost in a time which is orders of magnitude smaller than the typical slowing down time of about 0.1 second. Two classes of stellarators to which this general picture does not apply are described: quasihelically symmetric stellarators and a class of stellarators with vanishing bootstrap current in which the collisionless alpha particle confinement sufficiently improves. The influence of the modular ripple in optimized coil systems realising these configurations, the angular distribution of the fast alpha particle losses, and the application of the results to alpha particle confinement simulation experiments in next generation stellarators are also discussed.The response of the electron temperature profile shape to variations of the electron heating and density profiles is investigated for different confinement regimes. It is shown that the changes in r(Te) = -Te/(dTe/dr) exceed the measurement error if the shape of the electron heat diffusivity Xe(r) is kept fixed. The observed constancy of the response profiler r(Te)(r) in the outer half of the plasma is incompatible with such a fixed Xe(r) shape; ie a Te profile constraining mechanism must be present. Local transport laws of the form Xe oc r(Te)-alpha with alpha = 4 or above and Xe oc (dTe/dr) with alpha=2 or above yield the experimentally detected stiffness of the Te(r) shape but conflict with empirical Xe scalings. These results support the model of a self-organizing and adjusting Xe(r) causing Te profile invariance.History of Association/LaboratoryThe "Institut für Plasmaphysik GmbH"(IPP) was established in 1960 as a shareholding of the Max-Planck-Gesellschaft (MPG) and Werner Heisenberg. In 1971 it became an institute of MPG. IPP has been a EURATOM Association since 1961. With the PULSATOR tokamak experiment (1973 - 1979) IPP succeeded for the first time in penetrating the high-density plasma regime. Which is characterized by good confinement properties and low impurity density. The introduction of a new divertor concept in the experiment following, ASDEX (1980 - 1990), brought a further major improvement of the plasma purity which allowed in 1982, the discovery of a plasma state with enhanced energy confinement (H-regime). This H-mode state is expected to form a sufficient basis for the energy confinement in ITER.By using model plasmas IPP showed in 1964 that the confinement of a well-built stellarator (WENDELSTEIN Ib), in the collitional regime, is governed by classical losses only. At the same time the importance of resonances was discovered experimentally. In 1980, the WENDELSTEIN 7-A stellarator (1976 - 1986) demonstrated for the first time the possibility of confining a hot plasma just by applying external magnetic fields(without plasma current). A new important and improved stellarator confinement concept was discovered and elaborated and will form the basis for WENDELSTEIN 7-X. IPP hosts the NET Study group and is the European site of the ITER Design Activity. Present scientific and technical programmeThe research programme of IPP is aimed at developing and investigating the basic plasma physics required for a nuclear fusion reactor. For this purpose IPP design, construct, and conduct fusion experiments on the Tokamak ASDEX Upgrade and stellarator (WENDELSTEIN 7-AS, WENDELSTEIN 7-X). The objectives of ASDEX Upgrade, which started operation in 1990, are to investigate a divertor configuration suitable for a fusion reactor and study the interaction between the plasma and vessel wall under reactor-relevant edge plasma conditions. Thus, the results of ASDEX Upgrade will be an important input for the construction of NET/ITER. The WENDELSTEIN 7-AS advanced stellarator, as the first experiment to adopt a modular coil system for magnetic field generation, has achieved clearly improved plasma parameters and confinement properties in comparaison with its predecessor, WENDELSTEIN 7-A. These results together with detailed theoretical calculations will form the basis for the planned WENDELSTEIN 7-X stellarator, which is to demonstrate under fusion-relevant plasma parameters and with an optimized magnetic field the physical qualification of a reactor based on the stellarator concept. Other investigations are concerned with basic plasma-wall interaction and surface physics. StaffProfessionals : about 300Support staff : about 700 Yearly budget (expenditure 1994): about 77 MioECU Management structureHead of Research Unit : K. PINKAUBoard of Scientific Directors : Definition of the research programmeDirectorate : Regulation and supervision of the research programme Collaboration with other institutionsBesides European collaboration within EURATOM, IPP has concluded cooperation contracts with : FZK-Karlsruhe; KFA-Jülich; UKAEA-Culham; CIEMAT-Madrid; CRPP-Lausanne; DEMOKRITOS-Athens; Cork University-Ireland; FOM-Rijnhuizen; Inst. of Particle and Nuclear Phys.-Budapest; IST-Lisbon; NFR-Stockholm; RIS_-Roskilde; University of Helsinki; University of Marseille.In the framework of IEA Implementing Agreements, IPP cooperates with several US and Japanese fusion centers : Courant Institute-New York; general Atomics-San Diego; MIT-Boston; ORNL-Oak Ridge; PPPL-Princeton; University of Texas-Austin; Nat. Inst. for Fusion Science-Nagoya; RIKEN Institute-Tokyo; JAERI-Tokyo, University of Nagoya, IPP Kyoto.With the USSR there exists collaboration with : IAP-Nizhni Novgorod; Institute for General Physics-Moscow; Joffe Institute-St Petersburg; Phys. Tech. Institute-Kharkov, Technical University St. Petersburg. Programma(i) EAEC-FUSION 12C - Specific programme of research and training in the field of controlled thermonuclear fusion, 1994-1998 Argomento(i) Data not available Invito a presentare proposte Data not available Meccanismo di finanziamento Data not available Coordinatore Max-Planck-Institut für Plasmaphysik Contributo UE Nessun dato Indirizzo Boltzmannstrasse 2 85748 Garching bei München Germania Mostra sulla mappa Costo totale Nessun dato
