Design and measurement methods for a lithium vapor box similarity experiment.

The lithium vapor box divertor is a concept for handling the extreme divertor heat fluxes in magnetic fusion devices. In a baffled slot divertor, plasma interacts with a dense cloud of Li vapor which radiates and cools the plasma, leading to recombination and detachment. Before testing on a tokamak, the concept should be validated: we plan to study detachment and heat redistribution by a Li vapor cloud in laboratory experiments. Mass changes and temperatures are measured to validate a direct simulation Monte Carlo model of neutral Li. The initial experiment involves a 5 cm diameter steel box containing 10 g of Li held at 650 °C as vapor flows out a wide nozzle into a similarly sized box at a lower temperature. Diagnosis is made challenging by the required material compatibility with lithium vapor. Vapor pressure is a steep function of temperature, so to validate mass flow models to within 10%, absolute temperature to within 4.5 K is required. The apparatus is designed to be used with an analytical balance to determine mass transport. Details of the apparatus and methods of temperature and mass flow measurements are presented.

Methods of improving spatial resolution for IR spectroscopy in atmospheric-pressure plasma systems.

High-temperature, atmospheric pressure plasma systems operated in molecular gases present complex diagnostic challenges. Infrared spectroscopy has been used to make measurements of the absorbance spectrum of complex molecular gas mixtures and thereby calculate the concentrations and species temperatures in these systems. For atmospheric-pressure systems, high spatial gradients arise and high spatial-resolution measurements are thus desirable. Some systems have achieved increased spatial resolution by reducing the beam diameter. However, this increase in spatial resolution comes at the expense of the optical throughput. Here we propose modifying a commercial Fourier Transform, Infrared spectrometer system with a set of simple optical elements. This design allows for scannable, high spatial resolution absorbance spectrum measurements of a complex molecular gas mix. We analyze the signal-to-noise ratio for this design and compare it with the diameter reduction method. For sufficiently low plasma radiation levels, this design improves the signal-to-noise ratio relative to reducing the beam diameter size while transmitting nearly all of the beam power. However, whether this design can achieve the desired sub-mm spatial resolution depends on the radiating area of the infrared light source in the spectrometer.

Integrated plasma facing component calorimetry for measurement of shot integrated deposited energy in the NSTX-U.

The upgrade to the National Spherical Torus eXperiment (NSTX-U) [J. Menard et al., Nucl. Fusion 52, 083015 (2012)] increases the injected neutral beam power up to 12 MW and the plasma current up to Ip = 2 MA for plasma durations up to 5 s. The graphite plasma facing components have been re-designed to handle greater heat and energy fluxes than were seen in NSTX using a castellated design. We present the experimental testing and validation of a castellated graphite target, similar to the prototype tile design, instrumented with thermocouples at various depths in the castellation. During testing, incident heat flux is provided by a programmed electron beam system and surface temperatures are measured via infrared thermography directly viewing the target surface. It was found that the thermocouple response scaled linearly with the measured surface temperature rise regardless of thermocouple depth in the castellation. A sensitivity of 14.3 °C/kJ of deposited energy was found when treating individual castellations as a semi-infinite solid.

Design and characterization of a prototype divertor viewing infrared video bolometer for NSTX-U.

The InfraRed Video Bolometer (IRVB) is a powerful tool to measure radiated power in magnetically confined plasmas due to its ability to obtain 2D images of plasma emission using a technique that is compatible with the fusion nuclear environment. A prototype IRVB has been developed and installed on NSTX-U to view the lower divertor. The IRVB is a pinhole camera which images radiation from the plasma onto a 2.5 µm thick, 9 × 7 cm2 Pt foil and monitors the resulting spatio-temporal temperature evolution using an IR camera. The power flux incident on the foil is calculated by solving the 2D+time heat diffusion equation, using the foil's calibrated thermal properties. An optimized, high frame rate IRVB, is quantitatively compared to results from a resistive bolometer on the bench using a modulated 405 nm laser beam with variable power density and square wave modulation from 0.2 Hz to 250 Hz. The design of the NSTX-U system and benchtop characterization are presented where signal-to-noise ratios are assessed using three different IR cameras: FLIR A655sc, FLIR A6751sc, and SBF-161. The sensitivity of the IRVB equipped with the SBF-161 camera is found to be high enough to measure radiation features in the NSTX-U lower divertor as estimated using SOLPS modeling. The optimized IRVB has a frame rate up to 50 Hz, high enough to distinguish radiation during edge-localized-modes (ELMs) from that between ELMs.

Preliminary design of a tangentially viewing imaging bolometer for NSTX-U.

The infrared imaging video bolometer (IRVB) measures plasma radiated power images using a thin metal foil. Two different designs with a tangential view of NSTX-U are made assuming a 640 × 480 (1280 × 1024) pixel, 30 (105) fps, 50 (20) mK, IR camera imaging the 9 cm × 9 cm × 2 µm Pt foil. The foil is divided into 40 × 40 (64 × 64) IRVB channels. This gives a spatial resolution of 3.4 (2.2) cm on the machine mid-plane. The noise equivalent power density of the IRVB is given as 113 (46) µW/cm2 for a time resolution of 33 (20) ms. Synthetic images derived from Scrape Off Layer Plasma Simulation data using the IRVB geometry show peak signal levels ranging from ∼0.8 to ∼80 (∼0.36 to ∼26) mW/cm2.

In situ measurement of low-Z material coating thickness on high Z substrate for tokamaks.

Rutherford backscattering of energetic particles can be used to determine the thickness of a coating of a low-Z material over a heavier substrate. Simulations indicate that 5 MeV alpha particles from an (241)Am source can be used to measure the thickness of a Li coating on Mo tiles between 0.5 and 15 µm thick. Using a 0.1 mCi source, a thickness measurement can be accomplished in 2 h of counting. This technique could be used to measure any thin, low-Z material coating (up to 1 mg/cm(2) thick) on a high-Z substrate, such as Be on W, B on Mo, or Li on Mo. By inserting a source and detector on a moveable probe, this technique could be used to provide an in situ measurement of the thickness of Li coating on NSTX-U Mo tiles. A test stand with an alpha source and an annular solid-state detector was used to investigate the measurable range of low-Z material thicknesses on Mo tiles.

Electrical detection of liquid lithium leaks from pipe joints.

A test stand for flowing liquid lithium is under construction at Princeton Plasma Physics Laboratory. As liquid lithium reacts with atmospheric gases and water, an electrical interlock system for detecting leaks and safely shutting down the apparatus has been constructed. A defense in depth strategy is taken to minimize the risk and impact of potential leaks. Each demountable joint is diagnosed with a cylindrical copper shell electrically isolated from the loop. By monitoring the electrical resistance between the pipe and the copper shell, a leak of (conductive) liquid lithium can be detected. Any resistance of less than 2 kΩ trips a relay, shutting off power to the heaters and pump. The system has been successfully tested with liquid gallium as a surrogate liquid metal. The circuit features an extensible number of channels to allow for future expansion of the loop. To ease diagnosis of faults, the status of each channel is shown with an analog front panel LED, and monitored and logged digitally by LabVIEW.

Divertor electron temperature and impurity diffusion measurements with a spectrally resolved imaging radiometer.

A divertor imaging radiometer (DIR) diagnostic is being studied to measure spatially and spectrally resolved radiated power P(rad)(λ) in the tokamak divertor. A dual transmission grating design, with extreme ultraviolet (~20-200 Å) and vacuum ultraviolet (~200-2000 Å) gratings placed side-by-side, can produce coarse spectral resolution over a broad wavelength range covering emission from impurities over a wide temperature range. The DIR can thus be used to evaluate the separate P(rad) contributions from different ion species and charge states. Additionally, synthetic spectra from divertor simulations can be fit to P(rad)(λ) measurements, providing a powerful code validation tool that can also be used to estimate electron divertor temperature and impurity transport.

High-harmonic fast-wave power flow along magnetic field lines in the scrape-off layer of NSTX.

A significant fraction of high-harmonic fast-wave (HHFW) power applied to NSTX can be lost to the scrape-off layer (SOL) and deposited in bright and hot spirals on the divertor rather than in the core plasma. We show that the HHFW power flows to these spirals along magnetic field lines passing through the SOL in front of the antenna, implying that the HHFW power couples across the entire width of the SOL rather than mostly at the antenna face. This result will help guide future efforts to understand and minimize these edge losses in order to maximize fast-wave heating and current drive.

Continuous improvement of H-mode discharge performance with progressively increasing lithium coatings in the National Spherical Torus Experiment.

Lithium wall coatings have been shown to reduce recycling, improve energy confinement, and suppress edge localized modes in the National Spherical Torus Experiment. Here, we show that these effects depend continuously on the amount of predischarge lithium evaporation. We observed a nearly monotonic reduction in recycling, decrease in electron transport, and modification of the edge profiles and stability with increasing lithium. These correlations challenge basic expectations, given that even the smallest coatings exceeded that needed for a nominal thickness of the order of the implantation range.

High density Langmuir probe array for NSTX scrape-off layer measurements under lithiated divertor conditions.

A high density Langmuir probe array has been developed for measurements of scrape-off layer parameters in NSTX. Relevant scale lengths for heat and particle fluxes are 1-5 cm. Transient edge plasma events can occur on a time scale of several milliseconds, and the duration of a typical plasma discharge is ∼1 s. The array consists of 99 individual electrodes arranged in three parallel radial rows to allow both swept and triple-probe operation and is mounted in a carbon tile located in the lower outer divertor of NSTX between two segments of the newly installed liquid lithium divertor. Initial swept probe results tracking the outer strike point through probe flux measurements are presented.

Biasing, acquisition, and interpretation of a dense Langmuir probe array in NSTX.

A dense array of 99 Langmuir probes has been installed in the lower divertor region of the National Spherical Torus Experiment (NSTX). This array is instrumented with a system of electronics that allows flexibility in the choice of probes to bias as well as the type of measurement (including standard swept, single probe, triple probe, and operation as passive floating potential and scrape-off-layer SOL current monitors). The use of flush-mounted probes requires careful interpretation. The time dependent nature of the SOL makes swept-probe traces difficult to interpret. To overcome these challenges, the single- and triple-Langmuir probe signals are used in complementary fashion to determine the temperature and density at the probe location. A comparison to midplane measurements is made.

Thermoelectric magnetohydrodynamic stirring of liquid metals.

The direct observation of a thermoelectric magnetohydrodynamic (TEMHD) flow has been achieved and is reported here. The origin of the flow is identified based on a series of qualitative tests and corresponds, quantitatively, with a swirling flow TEMHD model. A theory for determining the dominant driver of a free-surface flow, TEMHD or thermocapillary (TC), is found to be consistent with the experimental results. The use of the analytical form for an open geometry develops a new dimensionless parameter describing the ratio of TEMHD to TC generated flows.

GLOB-1: a prospective randomised clinical phase III trial comparing vinorelbine-cisplatin with vinorelbine-ifosfamide-cisplatin in metastatic non-small-cell lung cancer patients.

BACKGROUND: The standard doublet, vinorelbine-cisplatin, was compared with a triplet of vinorelbine-ifosfamide-cisplatin, in terms of survival, in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: From February 1998 to June 1999, 259 chemonaïve patients entered the study and were randomised to receive either vinorelbine-cisplatin (NP; vinorelbine 30 mg/m(2) on days 1, 8 and 15 with cisplatin 80 mg/m(2) on day 1) or vinorelbine-ifosfamide-cisplatin (NIP; vinorelbine 25 mg/m(2) on days 1 and 8, ifosfamide 3 g/m(2) on day 1 and cisplatin 75 mg/m(2) on day 1), with both regimens being repeated every 3 weeks. All patients had stage IV or relapsed disease and a performance score of 0 or 1. RESULTS: The overall response rate was 34.6% for NP and 35.7% for NIP. Median and 1-year survival rates were 10.0 months and 38.4% for NP, and 8.2 months and 33.7% for NIP, respectively. A median of four cycles was administered in each arm. The major World Health Organization grade 3-4 toxicities for NP and NIP, respectively, were: neutropenia (20.3% compared with 9% of cycles), anaemia (4.1% compared with 5% of cycles), nausea and vomiting (22.2% compared with 19.4% of patients) and alopecia (5.6% compared with 29.8% of patients). Four toxic deaths occurred in the NP arm and eight in the NIP arm. CONCLUSIONS: The different schedules of vinorelbine in the two arms led to a greater survival in the NP arm without impairing the tolerance profile, although this is not statistically significant. This confirms that the two-drug combination NP is a reference treatment for metastatic NSCLC. The role of three-drug combinations remains questionable in this subset of patients.

[Progress in measurement of the calcaneus using ultrasonic methods in children and adolescents]. / Postepy w pomiarach kosci pietowej ilosciowa metoda ultradzwiekowa u dzieci i mlodziezy.

At present, Dual Energy X-ray Absorptiometry (DEXA) method is a reference method to diagnose osteoporosis. This method allows to measure bone density and bone mass, however bone quality can not be estimated. Quantitative ultrasound (QUS) method provides information about bone structure. The aim of our work was the evaluation of QUS method in healthy children, establishing reference values in cross-sectional study of healthy children aged 7-18 yrs and to examine the annual change of ultrasound parameters in prospective study at pubertal. Group of 530 girls and 369 boys was recruited from Warsaw schools, and right heel was measured with Achilles Plus apparatus. Measurements were repeated after 1 year, in a subgroup of 153 children aged 9-13 yrs. The method was adapted for paediatric measurements by using limiter of ultrasonic wave and pads for positioning foot in water chamber. Speed of sound (SOS) and broadband ultrasound attenuation (BUA) were measured and Stiffness index was calculated. Width of heel, at the same location as QUS measurement, was also measured using calipers. SOS, BUA and Stiffness values increased by age in boys and girls. BUA and Stiffness values were significantly higher in 15, 16 and 17 year old boys than in age-matched girls (in 18 yrs--only Stiffness). However, there were no significant sex differences in annual increase of SOS, BUA and Stiffness, although the biggest increase was observed between the age of 13-14 yrs for boys and 11-12 yrs for girls. That may reflect pubertal spurt of body growth but that relationship was not confirmed by annual increases calculated from cross-sectional data. Statistically significant correlation of SOS, BUA and Stiffness with body mass, height, body mass index (BMI) and heel width was observed. Normalization of SOS, BUA and Stiffness on heel width decreased force of that correlation but it was still statistically significant. Dynamics of SOS, BUA and Stiffness increase by age was higher in boys than in girls. This phenomenon is probably related to higher peak bone mass in men than in women, and lower risk of fracture in men, especially concerning hip. Increase of speed of sound, broadband ultrasound attenuation and stiffness index by age, and their correlations with body mass, height and body mass index reflects bone growth in children and adolescents. Broadband ultrasound attenuation and Stiffness index show sex differences in bone development in adolescence. Higher dynamics of the increase of speed of sound, broadband ultrasound attenuation and Stiffness index by age in boys confirms faster bone mass accumulation in boys than in girls.

Dielectric resonator-based side-access probe for muscle fiber EPR study.

We present a novel dielectric resonator (DR)-based resonant structure that accommodates aqueous sample capillaries in orientations that are either parallel (i.e., side-access) or perpendicular to the direction of an external (Zeeman) magnetic field, B(0). The resonant structure consists of two commercially available X-band DRs that are separated by a Rexolite spacer and resonate in the fundamental TE(01delta) mode. The separator between the DRs is used to tune the resonator to the desired frequency and, by appropriately drilled sample holes, to provide access for longitudinal samples, notably capillaries containing oriented, spin-labeled muscle fibers. In contrast to the topologically similar cylindrical TE(011) cavity, the DR-based structure has distinct microwave properties that favor its use for parallel orientation of lossy aqueous samples. For perpendicular orientation of a dilute (6.25 microM) aqueous solution of IASL spin label, the S/N ratio was at least one order of magnitude better for the side-access DR-based structure than for a standard TE(102) cavity. EPR spectra acquired for maleimide spin-labeled myosin filaments also revealed ca. 10 times better S/N ratio than those obtained with a standard TE(102) cavity. For the side-access DR with sample capillaries oriented either parallel or perpendicular to the external magnetic field, the Q- and filling factors are in good agreement with the theoretical estimates derived from the distribution of magnetic (H(1)) and electric (E(1)) components.

Biovariants of isolates of Pasteurella from domestic and wild ruminants.

A total of 608 bacterial isolates previously identified as Pasteurella haemolytica biotypes A and 3, P. trehalosi, and P. multocida, were separated into 73 distinct biovariants using 21 phenotypic characteristics. The largest group (54%) of wildlife isolates was identified as biogroup 2 and biogroup 2 variants. Biogroup 2 and biogroup 2 variants accounted for only 17% of isolates from domestic ruminants and were all from sheep. In contrast, 43% of isolates from domestic ruminants were identified as biogroup 1 and biogroup 1 variants, whereas only 6% of isolates from wildlife were identified in these groups. The majority of biogroup 1 isolates from wild ruminants were from 1 group of bighorn sheep in Arizona that were geographically separated from other wildlife sampled. Similarly, 1 biogroup 2 variant, 2E, was cultured only from free-ranging Dall sheep in Alaska. Twelve percent of domestic isolates and 6% of wildlife isolates were indole positive. The remaining isolates from wildlife (33%) and domestic animals (30%) were distributed among 53 distinct biovariants. None of these individual biovariants represented >4% of the total isolates. Phenotypic characterization was valuable for distinguishing between isolates from different hosts and from different geographic areas and can be used to assist in epidemiologic studies.

[Intrahepatic portocaval shunt as a new method for treating and prevention of bleeding from esophageal varices in portal hypertension]. / Wewnatrzwatrobowe zespolenie wrotno-systemowe jako nowa metoda w leczeniu i zapobieganiu krwotokom z zylaków przelyku w nadcisnieniu wrotnym.

UNLABELLED: The aim of this study was the presentation of percutaneous transjugular intrahepatic porto-systemic shunt (TIPS) and its place among the other methods of the treatment of esophageal variceal bleedings. In the period from June 1992 to December 1997, 31 cirrhotic patients with portal hypertension and recurrent variceal bleedings were submitted for TIPS. This group consisted of 14 female and 17 male patients, their age ranging from 17 to 68 years (average 52). According to Child-Pugh classification 4 patients represented group A, 11--group B and 16--group C. Each of these patient was admitted to our Department after recurrent bleeding, resistant to typical treatment: terlipressein infusion, balloon tamponade and endoscopic sclerotherapy. In 24 patients (78%) TIPS was performed successfully. In 7 cases TIPS was performed in candidates for orthotopic liver transplantation. CONCLUSIONS: TIPS is quite new, nearly 10 years old method for portal decompression. It is an effective and less invasive method than surgical procedures in the treatment of portal hypertension, especially in Child-Pugh group B and C patients if the sclerotherapy is not effective. It protects cirrhotic patients waiting for liver transplantation against the esophageal bleedings.

Pasteurella spp. in sympatric bighorn and domestic sheep.

Domestic sheep were sighted at different times from 1991 to 1993 on four Nevada (USA) ranges occupied by bighorn sheep. Nasal and pharyngeal swab samples were collected from both sheep species and cultured to determine if any strains of Pasteurella spp. were shared on range conditions after contact of the two species. Pasteurella spp. were isolated from all 38 bighorn sheep and 16 of 17 domestic sheep included in this study. The isolates were characterized on the bases of species, biotype, serotype, biogroup, and restriction enzyme analyses (REA) as well as ribotyping of bacterial DNA. A P. haemolytica biotype 3, biogroup 11 isolate from a domestic sheep had biochemical, REA, and ribotype profiles which were identical to those of isolates from three bighorn sheep on the same range. None of the other isolates were found to be common to the two sheep species. Disease was not detected in any of the bighorn populations. However, bighorn sheep populations were extirpated on two ranges while increasing on the other two, including the range on which P. haemolytica biotype 3, biogroup 11 strain was isolated. Declining sheep numbers were not correlated with the presence of any one strain of Pasteurella spp from the sheep.