[en] The structure of deuterated nickel hydroxide (H/D ca 0.1), prepared using hydrothermal techniques, has been refined using fixed-wavelength (lambda=1.386 A) powder neutron diffraction data collected at 298 K: Msub(r)=94.74[Ni(OD)₂], trigonal, Panti 3m 1, a=3.126 (1), c=4.593 (1)A, V=38.87 (4) A³, Z=1, Dsub(x)=4.05 g cm^-3 [Ni(OD)₂]. Rietveld refinement (Rsub(wp)=0.069, Rsub(exp)=0.025) indicates anisotropic D vibrations similar to those observed for Ca(OH)₂ and Mg(OH)₂ and after correction for thermal motion an O-D distance of 0.973 (4) A is obtained. Data from a high-surface-area Ni(OH)₂ sample show additional weak peaks which are attributed to the presence of H₂O defects; such a model is shown to be consistent with the observed infrared spectrum. (orig.)

No abstract available

[en] The Connecticut Geological Survey within the State Department of Environmental Protection (DEP) is working with the State Department of Health Services (DOHS) investigating the occurrence of radon in Connecticut. In 1985 and 1986, approximately 300 private and public water supply wells from 20 geological areas were tested for radon by the Toxic Hazards and Public Water Supply Sections of DOHS. Highest ground water radon was 130,240 pCi/1 from the Nonewaug Granite, a two-mica granite (range 10,720-130,240 pCi/1). Elevated radon was found in wells within several granitic gneisses: the Glastonbury Gneiss (3070-80,900 pCi/1), the Canterbury Gneiss (10,010-64,510 pCi/1), and the Hope Valley Alaskite Gneiss (4060-59,180 pCi/1). These Paleozoic and PreCambrian age rocks underlie --5% of the State. Intermediate radon levels were found in water from PreCambrian and Paleozoic age stratified metamorphic rocks where radon levels > 10,000 pCi/1 were widely scattered in these surveys. Relatively low ground water radon values were found in central Connecticut Mesozoic age sedimentary rock wells (390-8490 pCi/1) and in Paleozoic age carbonate rock wells (200-4130 pCi/1). Preliminary results from the ground (carbone) gamma radiation survey generally show a positive correlation with radon water analyses, enabling characterization of geological areas in Connecticut as radiation sources. DOHS is currently conducting 2,200 air tests in homes located in geologic areas selected from water analyses and the ground survey. All data is compiled on 1:24,000 maps to be included in multiple natural resource spatial analyses using an automated Geographic Information System. The analyses will explore relations between the distribution of radon levels and earth materials to better define the geologic areas and possible origins of radon in ground water and in indoor air

[en] Published in summary form only

[en] RF current drive has been proposed as a mechanism for reducing the tearing fluctuations that are responsible for anomalous energy transport in the RFP. To this end, a system for launching lower hybrid slow waves at 800MHz and n = 7.5 has been designed and implemented in MST. The antenna is an enclosed interdigital line using 1/4 wavelength resonators with an opening in the cavity through which the wave is coupled to the plasma. The power handling capability of the present antenna design has been investigated. Presently, the power handling the antenna begins to reflect nearly all the launched power is ∼ 3 kW. A boron nitride limiter assembly was added to the antenna and resulted in only a slight increase in the observed power limit. The antenna has been removed from the vacuum vessel and an inspection revealed no signs of damage after 16 months of operation inside of MST

No abstract available

[en] Inter-digital line antennas are being used to test the feasibility of lower hybrid current drive in MST. The antennas use λ/4 resonators and launch slow waves at 800 MHz with n parallel ∼ 7.5. Routine operation has been achieved with a good impedance match between antenna and plasma. High power antenna design improvements include larger vacuum feed-throughs, better impedance matching, and rf instrumentation on all resonators. The antenna and feed-through modeling was performed with CST Microwave Studio^TM. The pulse-forming network that powers the klystron is being upgraded to a 50 kV - 30 ms pulse. The goal for the LHCD system on MST is a modular design that can handle 300 kW per antenna

[en] Current drive using RF waves has been proposed as a means to reduce the tearing fluctuations responsible for anomalous energy transport in the RFP. A traveling wave antenna operating at 800 MHz is being used to launch lower hybrid waves into MST to assess the feasibility of this approach. Parameter studies show that edge density is a major factor in antenna/plasma coupling. Gas puffing near the antenna is shown to alter coupling without changing plasma conditions. Hard x-ray emission has been correlated to RF power and is seen to vary strongly with direction of power flow through the antenna

[en] Current drive using RF waves has been proposed as a means to reduce the tearing fluctuations responsible for anomalous energy transport in the RFP. A traveling wave antenna that operates at 800 MHz is being used to launch lower hybrid waves into MST to assess the feasibility of this approach. The power flowing through the antenna has been measured with pickup loops installed in the antenna backplane. The measured power damping length of 2-4 parallel wavelengths is consistent with analytic calculations. The damping length decreases with increasing plasma density and increases in improved confinement discharges. Localized hard x-ray emission has been observed when energy flows in either direction through the antenna

[en] The authors have designed and are conducting a current profile control experiment aimed at reducing fluctuations and improving confinement in RFP plasmas. Profile modification will be achieved via electrostatic injection of electrons from ∼ 30 miniature plasma sources. Each source produces a 1 kA electron beam which is dense (∼ 150 kA/cm² at 70 cm from the source), highly directional, and without large impurity content. An initial multi-injector experiment in which a total current of 5 kA was injected is completed. Results from this experiment is discussed. One of the promising results is an apparent increase in the plasma density by 50% and associated increase in the particle confinement time. Low impurity influx from the sources is essential for scaling up the injection system. MHD computations predict a current of ∼ 30 kA is necessary to suppress fluctuations in Madison Symmetric Torus (MST) and future experiments will employ an increasing number of injectors until this level is reached