bluuebunny/crossref_metadata_2025 huggingface dataset:
Intrapsychische und interpersonale Regulation von Emotionen im Therapieprozess
Authors: Znoj Hansjörg , Nick Lukas , Grawe Klaus
Published: October 2004

Zusammenfassung. In der vorliegenden Studie wurde der Einfluss des therapeutischen Bearbeitungsangebotes auf die nachfolgende Emotionsregulation der Patienten sequenzanalytisch untersucht. Dazu wurden Klassen von beobachtbaren Kategorien der Emotionsregulation sowie des therapeutischen Bearbeitungsangebotes gebildet und mit den Faktoren Therapieerfolg und Therapiephase in Verbindung gebracht. Als wichtigstes Ergebnis stellte sich eine Interaktion zwischen dem therapeutischen Angebot und der nachfolgenden Emotionsregulation der Patienten heraus. In der Anfangsphase erfolgreicher Therapien reagierten Patienten auf vertiefende Bearbeitungsangebote distanzierend und auf niederschwellige Bearbeitungsangebote mit weniger nonverbalem Ablenken. Dagegen konnten in der Endphase keine signifikanten Übergangswahrscheinlichkeiten mehr zwischen dem therapeutischem Angebot und nachfolgender Emotionsregulation festgestellt werden. Diese Zusammenhänge fanden sich bei wenig erfolgreichen Therapien nicht. Die Ergebnisse deuten auf eine positive Beziehung zwischen emotionaler Aktivierung und dem therapeutischen Erfolg hin.
MacNew Heart Disease Lebensqualitätsfragebogen nach Herzinfarkt:
Authors: Höfer Stefan , Benzer Werner , Brandt Dieter , Laimer Herbert , Schmid Peter , Bernardo Arthur , Oldridge Neil B.
Published: October 2004

Zusammenfassung. Theoretischer Hintergrund: Gesundheitsbezogene Lebensqualität (gLQ) stellt einen wichtigen Aspekt in der Evaluation medizinischer Behandlungen dar. Fragestellung: Der MacNew Heart Disease Lebensqualitätsfragebogen (MacNew) wurde entwickelt, um Gefühle von Patienten zu erfassen, die sich auf eine Reihe von Problemen bei Überlebenden eines akuten Herzinfarktes beziehen. Das Ziel dieser Studie war die Validierung der deutschen Version des MacNew an einer Patientengruppe nach Herzinfarkt. Methode: Der MacNew und die Short Form 36 (SF-36) wurden von 199 Patienten ausgefüllt. Die Retest-Reliabilität, die innere Konsistenz, sowie Valditiätsüberprüfungen und eine konfirmatorische Faktorenanalyse wurden berechnet. Ergebnisse: Mehr als 92% der Items wurden vollständig beantwortetet. Die konvergente Valdität mit den Skalen des SF-36 bewegten sich im Bereich von r = 0.36 bis 0.75 (p < .001). Die diskriminante Validität war zufriedenstellend hoch für alle Skalen (ANOVA, p < .01). Die Faktorenanalyse bestätigte die Drei-Faktoren-Struktur und erklärte 54,25% der Varianz. Reliabilitätskoeffizienten rangierten zwischen rtt = 0.72 und 0.87. Die innere Konsistenz liegt zwischen 0.90 und 0.97 auf. Die geringe Anzahl an fehlenden Daten belegt die hohe Akzeptanz der deutschen Version des MacNew bei Herzinfarktpatienten. Schlussfolgerung: Die Ergebnisse deuten darauf hin, dass die deutsche Version des MacNew ein valides, reliables und sensitives Instrument für die Messung der gLQ darstellt und vergleichbar mit der englischen Originalversion ist.
Sind “selbstorganisierende“ Therapiesysteme erfolgreicher?
Authors: Dohrenbusch Ralf , Scholz Oskar Berndt
Published: October 2004

Zusammenfassung. Theoretischer Hintergrund: In der Systemtheorie wird ein Therapiesystem als ein sich selbstorganisierender Prozess konzipiert, in dessen Verlauf sich das Verhalten der Systembeteiligten synchronisiert. Fragestellung: Inwiefern korrespondiert die Selbstorganisation von Therapiesystemen mit dem Therapieerfolg? Methode: Selbstorganisation wird als Reduktion der Dimensionalität des Antwortmusters in Therapiessitzungsprotokollen operationalisiert. Ermittlung der Faktorenstruktur der Therapiesitzungsprotokolle über die jeweils ersten und letzten 20 Sitzungen an 16 Therapieverläufen (Cattels O-Technik), Vergleich von Patienten mit konstanter vs. abnehmender Faktorenzahl in Bezug auf individualisierte und standardisierte Therapieerfolgsmaße und Interaktionsschwierigkeiten. Ergebnisse: Die Hypothese der Reduktion von Antwortdimensionen wird gestützt. Patienten aus selbstorganisierten Therapiesystemen waren kaum erfolgreicher, wohl aber konfliktvermeidender in ihrem Interaktionsverhalten als Patienten der Vergleichsgruppe. Schlussfolgerungen: Der Nutzen des Selbstorganisationskonzepts zur Erklärung des Zusammenhanges zwischen Prozess- und Ergebnismaßen in der Psychotherapieforschung wird durch die Ergebnisse relativiert. Es bleibt offen, in welchem Ausmaß die verwendete Operationalisierung der therapeutischen Selbstorganisation zur schwachen Prozess-Outcome-Relationen beigetragen hat.
“Trinken wegen sozialer Angst“ und “Soziale Angst wegen Trinken“:
Authors: Wagner Christof , Stangier Ulrich , Heidenreich Thomas , Schneider Ralf
Published: October 2004

Zusammenfassung. Theoretischer Hintergrund: Zur Erfassung von Aspekten sozialer Ängste bei Alkoholabhängigkeit wurden die beiden Fragebögen “Trinken wegen sozialer Angst“ (TWSA) und “Soziale Angst wegen Trinken“ (SAWT) entwickelt. TWSA erfasst Trinken zur Reduzierung von sozialen Ängsten. SAWT misst alkoholinduzierte soziale Ängste. Fragestellung: Es wurden die Reliabilität, faktorielle Validität und Konstruktvalidität überprüft. Methode: Psychometrische Analysen wurden an zwei Stichproben (n = 116 und n = 205) von alkoholabhängigen Patienten durchgeführt. Ergebnisse: Cronbachs a von TWSA ist .97 und von SAWT .95. Die Ergebnisse zweier Hauptkomponentenanalysen stützen die faktorielle Validität der Fragebögen, und die Korrelationen zu anderen Maßen sprechen für ihre Konstruktvalidität. Schlussfolgerungen: Die Ergebnisse ergeben erste Hinweis dafür, daß Alkoholkonsum zur “Selbstmedikation“ sozialer Ängste durch den TWSA und alkoholinduzierte soziale Ängste durch den SAWT reliabel und valide erfasst werden können.
Thermal structure and exhumation history of the Lesser Himalaya in central Nepal
Authors: Bollinger L. , Avouac J. P. , Beyssac O. , Catlos E. J. , Harrison T. M. , Grove M. , Goffé B. , Sapkota S.
Published: October 2004

The Lesser Himalaya (LH) consists of metasedimentary rocks that have been scrapped off from the underthrusting Indian crust and accreted to the mountain range over the last ∼20 Myr. It now forms a significant fraction of the Himalayan collisional orogen. We document the kinematics and thermal metamorphism associated with the deformation and exhumation of the LH, combining thermometric and thermochronological methods with structural geology. Peak metamorphic temperatures estimated from Raman spectroscopy of carbonaceous material decrease gradually from 520°–550°C below the Main Central Thrust zone down to less than 330°C. These temperatures describe structurally a 20°–50°C/km inverted apparent gradient. The Ar muscovite ages from LH samples and from the overlying crystalline thrust sheets all indicate the same regular trend; i.e., an increase from about 3–4 Ma near the front of the high range to about 20 Ma near the leading edge of the thrust sheets, about 80 km to the south. This suggests that the LH has been exhumed jointly with the overlying nappes as a result of overthrusting by about 5 mm/yr. For a convergence rate of about 20 mm/yr, this implies underthrusting of the Indian basement below the Himalaya by about 15 mm/yr. The structure, metamorphic grade and exhumation history of the LH supports the view that, since the mid‐Miocene, the Himalayan orogen has essentially grown by underplating, rather than by frontal accretion. This process has resulted from duplexing at a depth close to the brittle‐ductile transition zone, by southward migration of a midcrustal ramp along the Main Himalayan Thrust fault, and is estimated to have resulted in a net flux of up to 150 m2/yr of LH rocks into the Himalayan orogenic wedge. The steep inverse thermal gradient across the LH is interpreted to have resulted from a combination of underplating and post metamorphic shearing of the underplated units.
Fuzzy criteria for the evaluation of water resource systems performance
Authors: El‐Baroudy Ibrahim , Simonovic Slobodan P.
Published: October 2004

The sustainability of water resources is a critical factor in the development and the ongoing viability of healthy communities. Determining, with great certainty, that systems can be developed to ensure that sustainability is a great challenge to water resource systems engineers. The greatest design, planning, and management challenges lie in the engineer's limited ability to quantify potential future conditions. This study explores the utility of fuzzy set theory in the field of water resource systems reliability analysis and proposes three new fuzzy reliability measures: (1) a combined reliability‐vulnerability index, (2) a robustness index, and (3) a resiliency index. These measures were evaluated using two simple hypothetical case studies of water supply systems. The indices suggested are able to handle different fuzzy representations and different system conditions.
Methane emissions from lakes: Dependence of lake characteristics, two regional assessments, and a global estimate
Authors: Bastviken David , Cole Jonathan , Pace Michael , Tranvik Lars
Published: October 2004

Lake sediments are “hot spots” of methane production in the landscape. However, regional and global lake methane emissions, contributing to the greenhouse effect, are poorly known. We developed predictions of methane emissions from easily measured lake characteristics based on measurements for 11 North American and 13 Swedish lakes, and literature values from 49 lakes. Results suggest that open water methane emission can be predicted from variables such as lake area, water depth, concentrations of total phosphorus, dissolved organic carbon, and methane, and the anoxic lake volume fraction. Using these relations, we provide regional estimates from lakes in Sweden and the upper midwest of the United States. Considering both open water and plant‐mediated fluxes, we estimate global emissions as 8–48 Tg CH4 yr−1 (6–16% of total natural methane emissions and greater than oceanic emission), indicating that lakes should be included as a significant source in global methane budgets.
Spatial relationship of equatorial plasma bubbles and field‐aligned irregularities observed with an all‐sky airglow imager and the Equatorial Atmosphere Radar
Authors: Otsuka Y. , Shiokawa K. , Ogawa T. , Yokoyama T. , Yamamoto M. , Fukao S.
Published: October 2004

We report, for the first time, simultaneous two‐dimensional observations of 630‐nm airglow depletions and radar backscatter from field‐aligned irregularities (FAI) associated with equatorial plasma bubbles. Spatial distributions of backscatter were obtained by performing east‐west scans with the 47‐MHz Equatorial Atmosphere Radar (EAR) in West Sumatra, Indonesia. A 630‐nm airglow depletion, caused by a plasma bubble, was simultaneously observed with an all‐sky airglow imager. Both the airglow depletion and backscatter region appeared as band‐like structure elongated in the meridional direction with a zonal width of about 100 km. To compare the spatial structures of backscatter with that of airglow depletion, the backscatter was projected onto a horizontal plane at 250‐km altitude. Backscatter was found to occur within the entire airglow‐depleted region.
Effect of surface waves on Charnock coefficient under tropical cyclones
Authors: Moon Il‐Ju , Ginis Isaac , Hara Tetsu
Published: October 2004

The dependence of the air‐sea momentum flux on surface wave fields is investigated at very high winds under tropical cyclones. A coupled wave‐wind model is applied to estimate the momentum flux under ten hurricanes in the western Atlantic Ocean during 1998–2003. The model explicitly calculates the wave‐induced stress vector and the total wind stress vector from a given wind speed vector and a calculated wave spectrum. It is found that the neutral drag coefficient levels off at high wind speeds under tropical cyclones, being consistent with recent observations and previous modeling studies. The most important finding of this study is that the Charnock coefficient is mainly determined by two parameters: the input wave age (wave age determined by the peak frequency of wind energy input) and the wind speed, regardless of the complexity of the wave field under a real hurricane, and that the Charnock coefficient increases with the input wave age at very high winds.
Evaluation of two‐dimensional atmospheric water circulation fields in reanalyses by using precipitation isotopes databases
Authors: Yoshimura K. , Oki T. , Ichiyanagi K.
Published: October 2004

A global Rayleigh‐type H218O circulation model was forced by two reanalysis products, the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis and the European Centre for Medium‐Range Weather Forecasts (ECMWF) 15‐year reanalysis (ERA15) data sets, and the Global Network of Isotopes in Precipitation database was used to validate for 1979–1993 on monthly to interannual scales. Over Europe, ERA15 better matched observations at both timescales, owing mainly to better precipitation fields in ERA15, while in the tropics both produced similarly accurate isotopic fields. The isotope analyses diagnose accuracy of two‐dimensional water circulation fields in data sets with a particular focus on precipitation processes but in a slightly different manner over middle and high latitudes than over low latitudes: Analyses were more severe over the former regions.
Cirrus cloud microphysical and optical properties at southern and northern midlatitudes during the INCA experiment
Authors: Gayet Jean‐François , Ovarlez Joëlle , Shcherbakov Valéry , Ström Johan , Schumann Ulrich , Minikin Andreas , Auriol Frédérique , Petzold Andreas , Monier Marie
Published: October 2004

Microphysical and optical measurements were performed in midlatitude cirrus clouds at temperatures between −33°C and −60°C during southern and northern Interhemispheric Differences in Cirrus Properties From Anthropogenic Emissions (INCA) field experiments carried out at equivalent latitudes (53°S and 55°N) from Punta Arenas in the Southern Hemisphere (SH, Chile) and Prestwick in the Northern Hemisphere (NH, Scotland). The aim of this paper is to analyze the microphysical and optical properties of cirrus clouds and to compare the results of the two campaigns. Compared with the mean properties of cirrus clouds in SH, the cirrus sampled in NH were characterized by a greater concentration of ice crystals (2.2 cm−3 versus 1.4 cm−3, respectively) with a lower effective diameter (36 μm versus 42 μm, respectively). A significant contrast in extinction coefficient was also evidenced with larger values in NH than in SH (0.61 km−1 versus 0.49 km1, respectively), whereas no significant differences in the ice water content were observed (8 mg m−3). The first measurements of the asymmetry parameter obtained in midlatitude cirrus clouds revealed rather uniform particle scattering properties (median g values between 0.76 and 0.78) with small differences between SH and NH (0.770 versus 0.767, respectively). No significant differences in crystal shape were evidenced between the two data sets. For similar environmental conditions (i.e., over a similar range of temperature and vertical velocity) and for given values of the relative humidity, the comparisons clearly show distinct differences between the microphysical and optical properties of cirrus clouds sampled in the SH and NH field experiments. These differences may be related to the contrasts in cirrus freezing thresholds in terms of relative humidity over ice for onset of clouds, which is about 20% lower in NH than in SH, as reported in previous INCA data analyses. Nevertheless, definite conclusions are hampered by the large natural variability of cirrus cloud properties and the limited number of flights performed, not forgetting both the actual freezing mechanisms and potential differences in small‐scale dynamical variability, which are still insufficiently understood.
On extremal quantum states of composite systems with fixed marginals
Authors: Rudolph Oliver
Published: October 2004

We study the convex set C(ρ1,ρ2) of all bipartite quantum states with fixed marginal states ρ1 and ρ2. The extremal states in this set have recently been characterized by Parthasarathy [Ann. Henri Poincaré (to appear), quant-ph/0307182]. Here we present an alternative necessary and sufficient condition for a state in C(ρ1,ρ2) to be extremal. Our approach is based on a canonical duality between bipartite states and a certain class of completely positive maps and has the advantage that it is easier to check and to construct explicit examples of extremal states. In dimension 2×2 we give a simple new proof for the fact that all extremal states in C(121,121) are precisely the projectors onto maximally entangled wave functions. We also prove that in higher dimension this does not hold and construct an explicit example of an extremal state in C(131,131) that is not maximally entangled. Generalizations of this result to higher dimensions are also discussed.
A Landau fluid model for dispersive magnetohydrodynamics
Authors: Passot T. , Sulem P. L.
Published: October 2004

A monofluid model with Landau damping is presented for strongly magnetized electron-proton collisionless plasmas whose distribution functions are close to bi-Maxwellians. This description that includes dynamical equations for the gyrotropic components of the pressure and heat flux tensors, extends the Landau-fluid model of Snyder, Hammett, and Dorland [Phys. Plasmas 4, 3974 (1997)] by retaining Hall effect and finite Larmor radius corrections. It accurately reproduces the weakly nonlinear dynamics of dispersive Alfvén waves whose wavelengths are large compared to the ion inertial length, whatever their direction of propagation, and also the rapid Landau dissipation of long magnetosonic waves in a warm plasma.
Point-to-point analysis of MSE data for plasma diagnostics and control
Authors: Giannella R. , Hawkes N. C. , Jayakumar R. , Makowski M. , Zabeo L.
Published: October 2004

A local analysis technique is presented for the analysis of MSE data to deduce the safety factor q in tokamak discharges. The technique preserves as much as possible the individuality of every single measure by a simple rule of translation of magnetic field pitch angle measurements into q-values. Based on a geometric approach, and the observation that the flux surfaces shapes are strongly constrained by that of the last closed flux surface (LCFS), by the position of the magnetic axis and by a few more global parameters, it provides a robust, nonsubjective, accurate technique that is useful for the experimental study of q-profiles and for the evaluation of its uncertainties. It also provides a useful tool for plasma control experiments as it does not submit data to a preliminary search of minima in a multi-parametric domain, a procedure that may lead to jumps in the time behavior of the produced results.
Stability of spot and ring solutions of the diblock copolymer equation
Authors: Ren Xiaofeng , Wei Juncheng
Published: October 2004

The Γ-convergence theory shows that under certain conditions the diblock copolymer equation has spot and ring solutions. We determine the asymptotic properties of the critical eigenvalues of these solutions in order to understand their stability. In two dimensions a threshold exists for the stability of the spot solution. It is stable if the sample size is small and unstable if the sample size is large. The stability of the ring solutions is reduced to a family of finite dimensional eigenvalue problems. In one study no two-interface ring solutions are found by the Γ-convergence method if the sample is small. A stable two-interface ring solution exists if the sample size is increased. It becomes unstable if the sample size is increased further.
Deposition diagnostics for next-step devices (invited)
Authors: Skinner C. H. , Roquemore A. L. ,   the NSTX team, Bader A. , Wampler W. R.
Published: October 2004

Deposition in next-step devices such as ITER will pose diagnostic challenges. Codeposition of hydrogen with carbon needs to be characterized and understood in the initial hydrogen phase in order to mitigate tritium retention and qualify carbon plasma facing components for DT operations. Plasma facing diagnostic mirrors will experience deposition that is expected to rapidly degrade their reflectivity, posing a challenge to diagnostic design. Some eroded particles will collect as dust on interior surfaces and the quantity of dust will be strictly regulated for safety reasons however, diagnostics of in-vessel dust are lacking. We report results from two diagnostics that relate to these issues. Measurements of deposition on NSTX with 4 Hz time resolution have been made using a quartz microbalance in a configuration that mimics that of a typical diagnostic mirror. Often deposition was observed immediately following the discharge suggesting that diagnostic shutters should be closed as soon as possible after the time period of interest. Material loss was observed following a few discharges. A novel diagnostic to detect dust particles on remote surfaces was commissioned on NSTX.
Development of cooled UV, visible and IR windows for quasicontinuous operation of the W7-X stellarator
Authors: König R. , Ogorodnikova O. , Hildebrandt D. , Grosser K. , Sehren C. von , Baldzuhn J. , Burhenn R. , Mertens Ph. , Pospieszczyk A. , Schweer B. , Schmidt H. , Klinger T.
Published: October 2004

The stellarator W7-X will be capable of running 30 min discharges. The expected continuous radiation power loads on plasma-facing optical components of 50 kW/m2 will be predominantly deposited in the form of short wavelength radiation (<60 nm) within the first millimeter of any window material. At such high heat loads actively water cooled windows are essential. The finite element-code ANSYS was used to calculate temperature and stress distributions across the windows for different window materials (CaF2, MgF2, quartz, ZnSe, sapphire), diameters, and thicknesses to explore any window design limitations resulting from the material properties of the different window substrates. First tests of a prototype water cooled window (coated with water-based colloidal graphite for effective IR absorption) in a specially designed vacuum test chamber equipped with a large surface vacuum compatible high power IR heater are being reported on. The temporal evolution of the temperature at different locations on the air side of the window and its surrounding structure is being monitored by several PT100 resistive thermometers while the spatial heat distribution across the cooled windows on their air and vacuum side is being measured with two IR cameras operating at 4 and 10 μm.
Real-time digital signal processor-based system for MHD mode identification in ISTTOK
Authors: Carvalho B. B. , Fernandes H. , Sousa J. , Varandas C. A. F.
Published: October 2004

A diagnostic for the magnetohydrodynamic (MHD) mode identification is being implemented on the Tokamak ISTTOK using the signals from the set of 12 equally spaced Mirnov coils. These poloidal magnetic field sensors have been recently installed inside the vessel and were designed for plasma shape and position equilibrium determination. The data acquisition and processing system is based on a locally developed galvanic isolated, eight channel fast PCI transient recorder module with a 2 Msamples/s sampling rate, 14   bit resolution, and a total memory of 256   Mwords. This module includes a digital signal processor and field programmable gate array allowing real-time determination of MHD modes using advanced identification algorithms, in a submillisecond cycle time. Poloidal m number and amplitude measurements are available in real time to feed event-driven active control systems. This solution enables high performance distributed computing, effective data reduction, and event detection at a relatively low cost.
Time–frequency analysis of nonstationary fusion plasma signals: A comparison between the Choi–Williams distribution and wavelets
Authors: Figueiredo A. C. A. , Nave M. F. F. ,   EFDA-JET contributors
Published: October 2004

The continuous wavelet transform scalogram, and recently the Choi–Williams distribution, have both been used to improve upon the short-time Fourier transform spectrogram in the analysis of some nonstationary phenomena in fusion plasmas. Here, a comparison is made with real fusion plasma signals that shows the advantages of the Choi–Williams distribution over wavelets as a complementary tool to the spectrogram.
Scanning internal probe for plasma particle, fluctuation, and LIF tomographic measurements
Authors: Biloiu Costel , Scime Earl , Sun Xuan , McGeehan Brendan
Published: October 2004

An internal scanning probe capable of spatially resolved measurements throughout a horizontal (r,z) cross section of the expansion region between a helicon plasma source and an expansion chamber is described. For complete diagnosis of the expanding magnetoplasma, the probe is designed to simultaneously measure the electron temperature, the electron density, the plasma potential, the magnetic fluctuation spectrum in three dimensions, and the two-dimensional ion velocity distribution function (through a tomographic inversion method). The probe design and operational characteristics as well as representative measurements are presented.
Radiation-induced thermoelectric sensitivity (RITES) in ITER prototype magnetic sensors
Authors: Vayakis G. , Sugie T. , Kondoh T. , Nishitani T. , Ishitsuka E. , Yamauchi M. , Kawashima H. , Shikama T.
Published: October 2004

This report summarizes the results of in situ measurements of noninductive voltages developed across prototype International Thermonuclear Experimental Reactor (ITER) magnetic coils performed at the Japan Materials Test Reactor. The voltages appear to be mainly thermoelectric in origin, with the thermal sensitivity developing gradually through irradiation and the thermal gradients supplied by nuclear heating. Possible mechanisms and circuits within the coils that can contribute to this radiation-induced thermoelectric sensitivity are described, and schemes to improve the ITER coil design are outlined.
Observations of sheared radial electric-field effects on turbulence suppression
Authors: Yoshida M. , Cho T. , Hirata M. , Tokioka S. , Miyake Y. , Numakura T. , Kohagura J. , Miyoshi S.
Published: October 2004

Significant effects of sheared transverse electric fields in plasmas on both turbulent fluctuations and drift waves are experimentally demonstrated with improvement in plasma confinement for the first time in the tandem mirror GAMMA 10. These electric-shear effects are performed on the basis of a factor of 2 advance in ion-confining potential formation. For analyzing these phenomena in detail, we develop a novel electrostatic ion-energy spectrometer array consisting of five spectrometer units. The spectrometer arrays have the characteristic advantage of having no disturbances from potential-producing electron-cyclotron wave heated energetic electrons. Totally four array arms having each a 90° separation located on each GAMMA 10 end wall make it possible to observe two-dimensionally resolved radial-distribution profiles of plug and/or central potentials as well as radially produced shear of electric fields along with the earlier-described fluctuation signals simultaneously.
Fast neutral pressure gauges in NSTX
Authors: Raman R. , Kugel H. W. , Gernhardt R. , Provost T. , Jarboe T. R. , Soukhanovskii V.
Published: October 2004

Successful operation in the National Spherical Torus Experiment (NSTX) of two prototype fast-response micro ionization gauges during plasma operations has motivated us to install five gauges at different toroidal and poloidal locations. These have a nitrogen equivalent lower pressure limit of a conventional ion gauge (∼3×10−10 Torr) and an upper pressure limit of 50 mTorr. On NSTX, they have a useful operating range of 1×10−5 Torr–4 mTorr in deuterium. The modified Princeton Divertor Experiment-type Penning gauges are well suited for pressure measurements in the NSTX divertor where the toroidal field is relatively high. It is capable of operation over a pressure range of 1×10−5Torr–4 mTorr in deuterium. The gauge calibration has been stable for 2 years and the gauges have required no maintenance. Behind the NSTX outer divertor plates where the field is lower, an unshielded ion gauge of a new design has been installed.
Method to deduce local impurity transport quantities from the evolution of tomographically reconstructed bolometer signals during tracer injection at TJ-II
Authors: Zurro B. , Ochando M. A. , Baciero A. , McCarthy K. J. , Medina F. , López-Sánchez A. , Rapisarda D. , Jimenez D. , Fernández A. , Pastor I. , Herranz J. , Dux R.
Published: October 2004

A method to obtain local impurity transport from injected impurities in the TJ-II stellarator is presented. By using a one-dimensional full impurity transport code STRAHL, the transient behavior of the localized response of global radiation monitors to impurity injection is matched by the code results using an iterative method. The distinctive feature of the present approach with respect to other works is that we use tomographically reconstructed evolutions of total radiated power from a bolometer array. The method will be illustrated with analysis of blow-off results of experiments performed in the TJ-II stellarator.
Electromagnetic pulse generation within a petawatt laser target chamber
Authors: Mead M. J. , Neely D. , Gauoin J. , Heathcote R. , Patel P.
Published: October 2004

Recent work has been undertaken to characterize the electromagnatic pulse (EMP) generated by the high temperature high density plasma produced by a petawatt laser. This was to evaluate the susceptibility to malfunction and damage of equipment and diagnostics for the new Orion laser. EMP measurement were made using moebius loop antennas fitted inside the target chamber of the Vulcan petawatt laser at the Rutherford Appleton Laboratory. These show the EMP as a 63 MHz transient which decays from a peak magnetic field of around 4.3 A/m. A theoretical model presented assumes the EMP is produced by an impulse of 1012 electron emanating from the target, which charge the chamber wall causing it to ring at natural frequency. The theoretical model provides an estimate of the EMP measured in the Vulcan petawatt target chamber and will be used for the design of the Orion laser.
Integrated data analysis of fusion diagnostics by means of the Bayesian probability theory
Authors: Fischer R. , Dinklage A.
Published: October 2004

Integrated data analysis (IDA) of fusion diagnostics is the combination of heterogeneous diagnostics to obtain validated physical results. Benefits from the integrated approach result from a systematic use of interdependencies; in that sense IDA optimizes the extraction of information from sets of different data. For that purpose IDA requires a systematic and formalized error analysis of all (statistical and systematic) uncertainties involved in each diagnostic. Bayesian probability theory allows for a systematic combination of all information entering the diagnostic model by considering all uncertainties of the measured data, the calibration measurements, and the physical model. Prior physics knowledge on model parameters can be included. Handling of systematic errors is provided. A central goal of the integration of redundant or complementary diagnostics is to provide information to resolve inconsistencies by exploiting interdependencies. A comparable analysis of sets of diagnostics (meta-diagnostics) is performed by combining statistical and systematical uncertainties with model parameters and model uncertainties. Diagnostics improvement and experimental optimization and design of meta-diagnostics will be discussed.
Electromagnetic compatibility management for fast diagnostic design
Authors: Raimbourg J.
Published: October 2004

This article presents an overview of electromagnetic compatibility (EMC) management for fast diagnostic design. We will present and detail the classical approach in EMC. This approach can be successfully applied for installations where a single engineering entity has the authority to prescribe and enforce a certain compatibility level. Most of the time, strict application of generic standards is required for fast diagnostics. Nethertheless, the pulse perturbation must be synchronized to the fast diagnostic operation. Some “traditional” techniques, such as star-earthing and bonding cable screens at one end, have been shown to be inadequate for fast diagnostic design. Our laser facility, the LIL, will be able to focus up to 60 kJ into a volume of less than 1 mm3. We have to evaluate the electromagnetic pulse (EMP) where diagnostics, cables, and oscilloscopes will be installed. We performed electromagnetic measurements inside and outside the OMEGA target chamber. The electromagnetic pulse generated by the target chamber contains very high frequency components above 1 GHz. The electric field is around a few kV/m outside and goes up to 20 kV/m inside the target. We designed a specific electromagnetic probe for pulse measurement with a rise time down to 100 ps. An ultrashort rise time EMP bench test was built to test apparatus before installation around a target chamber. It produces an electric field higher than 5 kV/m with a rise time under 100 ps.
ITER diagnostics: Integration and engineering aspects
Authors: Walker C. I. , Costley A. E. , Itami K. , Kondoh T. , Sugie T. , Vayakis G. , Malaquias A.
Published: October 2004

ITER diagnostic equipment is integrated in six equatorial and 12 upper ports, five lower ports, and the 16 divertor cassettes directly in front of them, and at many locations in the vacuum vessel. The integration has to satisfy multiple requirements and constraints and at the same time must deliver the required diagnostic performance. Design work has been carried out in problematical and interfacing areas for most diagnostics. The main diagnostic support components, the port plugs and divertor port racks, comprise common structural elements with dedicated modules from several diagnostics. The scope of the engineering task is summarized and an overview of the integration of the diagnostic equipment is given. The engineering work to date represents the input to the port engineering tasks of the construction phase with common or repeated elements being assessed for feasibility, resolving issues, and identifying show stoppers. It has been dominated by allocation and spatial integration in the tokamak. The work that follows will be more oriented towards the acceptability for operation, suitability for function, and conformity for licensing.
TJ-II wave forms analysis with wavelets and support vector machines
Authors: Dormido-Canto S. , Farias G. , Dormido R. , Vega J. , Sánchez J. , Santos M. ,   The TJ-II Team
Published: October 2004

Since the fusion plasma experiment generates hundreds of signals, it is essential to have automatic mechanisms for searching similarities and retrieving of specific data in the wave form database. Wavelet transform (WT) is a transformation that allows one to map signals to spaces of lower dimensionality. Support vector machine (SVM) is a very effective method for general purpose pattern recognition. Given a set of input vectors which belong to two different classes, the SVM maps the inputs into a high-dimensional feature space through some nonlinear mapping, where an optimal separating hyperplane is constructed. In this work, the combined use of WT and SVM is proposed for searching and retrieving similar wave forms in the TJ-II database. In a first stage, plasma signals will be preprocessed by WT to reduce their dimensionality and to extract their main features. In the next stage, and using the smoothed signals produced by the WT, SVM will be applied to show up the efficiency of the proposed method to deal with the problem of sorting out thousands of fusion plasma signals.

From observation of several experiments, our WT+SVM method is very viable, and the results seems promising. However, we have further work to do. We have to finish the development of a Matlab toolbox for WT+SVM processing and to include new relevant features in the SVM inputs to improve the technique. We have also to make a better preprocessing of the input signals and to study the performance of other generic and self custom kernels. To reach it, and since the preprocessing stages are very time consuming, we are going to study the viability of using DSPs, RPGAs or parallel programming techniques to reduce the execution time.
Space charge effects downstream from an electric grid in magnetized plasma
Authors: Shadman K.
Published: October 2004

This paper presents a one-dimensional treatment of Poisson’s equation for the solution of the electric potential in a region downstream from a grid electrode. The motivation for this study is to gain an understanding of the effects of space charge inside a gridded energy analyzer that is being used to measure the electron distribution function in magnetized plasma. The analysis bring into light an ideal regime where these effects naturally isolate the electron current to a collector placed downstream from the grid. The study also gives generic relations for the variation of the space charge limited electron and ion currents with the grid voltage. These relations can be compared with an actual characteristic as a means of diagnosing the impact of space charge inside the analyzer.
Electron emissive electrode for the plasma biasing experiment on tokamak ISTTOK
Authors: Figueiredo H. , Nedzelskiy I. S. , Silva C. , Varandas C. A. F. , Cabral J. A. C. , Galvão R. M. O.
Published: October 2004

This paper presents the description and operational characteristics of an emissive electrode (EE) used in edge biasing experiments on small tokamak ISTTOK. The EE consists of a lanthanum hexaboride (LaB6) electron emitter heated by a tungsten filament. The emissive characteristics of EE have been investigated both in a simple vacuum diode configuration on test facility and in the plasma of tokamak. Emissive currents up to 20 A have been observed during negative bias in plasma accompanied by a strong modification of the electric field. The EE proved to be a valuable tool on the control of the plasma electric field, allowing a detailed investigation of its importance in plasma confinement.
Distributed real time data processing architecture for the TJ-II data acquisition system
Authors: Ruiz M. , Barrera E. , López S. , Machón D. , Vega J. , Sánchez E.
Published: October 2004

This article describes the performance of a new model of architecture that has been developed for the TJ-II data acquisition system in order to increase its real time data processing capabilities. The current model consists of several compact PCI extension for instrumentation (PXI) standard chassis, each one with various digitizers. In this architecture, the data processing capability is restricted to the PXI controller’s own performance. The controller must share its CPU resources between the data processing and the data acquisition tasks. In the new model, distributed data processing architecture has been developed. The solution adds one or more processing cards to each PXI chassis. This way it is possible to plan how to distribute the data processing of all acquired signals among the processing cards and the available resources of the PXI controller. This model allows scalability of the system. More or less processing cards can be added based on the requirements of the system. The processing algorithms are implemented in LabVIEW (from National Instruments), providing efficiency and time-saving application development when compared with other efficient solutions.
Effect of electron temperature fluctuations on slowly swept Langmuir probe measurements
Authors: Rudakov D. L. , Boedo J. A. , Moyer R. A. , Stangeby P. C. , McLean A. , Watkins J. G.
Published: October 2004

Swept Langmuir probes are widely used to measure electron temperature (Te) in laboratory plasmas by performing an exponential fit to the measured volt–ampere (I–V) characteristic. Often the probe voltage sweep frequency is much lower than the characteristic frequencies of the plasma fluctuations and a time-averaged I–V characteristic is used for the fit. We show by numerical modeling that in the presence of Te fluctuations with frequencies well above the voltage sweep frequency this standard technique applied to a swept single probe tends to read higher than the actual time-averaged Te provided no correlated plasma potential (Vp) fluctuations are present. In the presence of coupled Te and Vp fluctuations a slowly swept single probe may read either higher or lower than the average Te, depending on the relative amplitude and phase of the temperature and potential fluctuations. In contrast, swept double probe measurements of Te are virtually unaffected by either Te or Vp fluctuations.
On the Bell–Plesset effects: The effects of uniform compression and geometrical convergence on the classical Rayleigh–Taylor instability
Authors: Epstein R.
Published: October 2004

The Rayleigh–Taylor (RT) instability of an accelerating fluid interface is examined considering the effects of compression and geometrical convergence on incompressible perturbations of an interface separating two homogeneous compressible fluid layers of different mass densities. These effects occur in the implosion of inertial confinement fusion capsules. A complete description of Bell–Plesset effects is presented in terms of a simple model formulated in terms of the mass amplitude of perturbations of planar, cylindrical, and spherical interfaces. This formulation makes a clear distinction between perturbation growth driven by buoyant force—the RT instability—and modifications of perturbation behavior by compression and geometrical convergence—the Bell–Plesset (BP) effects [G. I. Bell, Los Alamos National Laboratory, Report LA-1321 (1951); M. S. Plesset, J. Appl. Phys. 25, 96 (1954)]. BP effects modify RT growth rates and may affect RT stability criteria, but they are not a distinct instability. These effects vary widely in their nature and importance from application to application, depending on the relative rates of RT growth, radial convergence, and uniform compression. Limiting cases are compared and contrasted. BP effects are generally different for each component of the perturbation solution pair. BP effects on perturbation growth in cylindrical implosion experiments have been analyzed successfully [e.g., W. W. Hsing et al., Phys. Plasmas 4, 1832 (1997)], in terms of an incomplete single-component solution that is indistinguishable from unperturbed flow, indicating that the component exhibiting true ongoing perturbed motion is largely absent. This static mass perturbation solution is often treated as the one and only BP effect, even though it occurs as one of a pair of solutions and only in the limit of a vanishing RT effect.
Simulation of plasma afterglow phase in an inertial fusion energy chamber
Authors: Pigarov A. Yu. , Frolov B. K. , Krasheninnikov S. I. , Petzoldt R. W. , Goodin D. T.
Published: October 2004

A zero-dimensional model that describes the evolution of plasma and gas parameters during the afterglow phase of cyclic operation of an inertial fusion energy chamber is developed. The afterglow phase determines the conditions for next fuel-target injection and therefore its thorough analysis is very important for conceptual design of inertial fusion power plants. The model incorporates important effects of intrinsic impurity ion radiation on plasma cooling as well as of chamber opacity with respect to resonance radiation on plasma recombination in the working chamber. The decay times for the plasma and gas energy and, in particular, their dependence on initially stored energy, chamber size, and background gas concentration are analyzed. The heat power load onto the cryogenic fuel target due to residual plasma, gas, and radiation field is calculated. It is found that the higher the background gas density, the longer is the time into the afterglow phase necessary to reduce the heat flux on the target to an acceptable level.
Bubble merger model for the nonlinear Rayleigh–Taylor instability driven by a strong blast wave
Authors: Miles A. R.
Published: October 2004

A bubble merger model is presented for the nonlinear evolution of the Rayleigh–Taylor instability driven by a strong blast wave. Single bubble motion is determined by an extension of previous buoyancy-drag models extended to the blast-wave-driven case, and a simple bubble merger law in the spirit of the Sharp–Wheeler model allows for the generation of larger scales. The blast-wave-driven case differs in several respects from the classical case of incompressible fluids in a uniform gravitational field. Because of material decompression in the rarefaction behind the blast front, the asymptotic bubble velocity and the merger time depend on time as well as the transverse scale and the drive. For planar blast waves, this precludes the emergence of a self-similar regime independent of the initial conditions. With higher-dimensional blast waves, divergence restores the properties necessary for the establishment of the self-similar state, but its establishment requires a very high initial characteristic mode number and a high Mach number for the incident blast wave.
Low-frequency instability of circularly polarized microwave-pulsed-field-produced plasmas
Authors: Shokri B. , Ghorbanalilu M.
Published: October 2004

The plasma produced by a high-power pulsed circularly polarized microwave field which is much weaker than atomic fields is investigated in the nonrelativistic limit. It is shown that the resulting electron distribution function is nonequilibrium and anisotropic. Furthermore, the general dispersion equation is derived and analyzed to study low-frequency ion oscillations. It will be shown that there is an instability in the aforementioned system only when the ion density exceeds a critical value.
Damping of sound waves propagating in optically thin plasmas
Authors: Ibáñez S. Miguel H.
Published: October 2004

The effects of the second viscosity on sound waves propagating in plasmas at thermochemical equilibrium are analyzed. It is found that this viscosity can be more important than the dynamical viscosity as well as than the thermometric conductivity, in particular, in photoionized plasmas with arbitrary metallicity Z. The strongest damping per unit wavelength always occurs for sound waves with a period of the order of the ionization relaxation time. Additionally, such a damping is more efficient for plasmas with solar abundances (Z=1) than for primordial plasmas (Z=0). In collisionally heated pure hydrogen plasmas the second viscosity becomes zero.
On P-adic λ-model on the Cayley tree
Authors: Khamraev Murod , Mukhamedov Farruh
Published: October 2004

We consider a nearest-neighbor p-adic λ-model with spin values ±1 on the Cayley tree of order k⩾1. We prove that a p-adic Gibbs measure is unique for p⩾3. If p=2 then we find a condition which guarantees uniqueness of p-adic Gibbs measure. Besides, the results are applied to the p-adic Ising model.
The Newtonian limit of the relativistic Boltzmann equation
Authors: Calogero Simone
Published: October 2004

The relativistic Boltzmann equation for a constant differential cross section and with periodic boundary conditions is considered. The speed of light appears as a parameter c>c0 for a properly large and positive c0. A local existence and uniqueness theorem is proved in an interval of time independent of c>c0 and conditions are given such that in the limit c→+∞ the solutions converge, in a suitable norm, to the solutions of the nonrelativistic Boltzmann equation for hard spheres.
Exact series solution to the two flavor neutrino oscillation problem in matter
Authors: Blennow Mattias , Ohlsson Tommy
Published: October 2004

In this paper, we present a real nonlinear differential equation for the two flavor neutrino oscillation problem in matter with an arbitrary density profile. We also present an exact series solution to this nonlinear differential equation. In addition, we investigate numerically the convergence of this solution for different matter density profiles such as constant and linear profiles as well as the Preliminary Reference Earth Model describing the Earth’s matter density profile. Finally, we discuss other methods used for solving the neutrino flavor evolution problem.