Experiments, high-flux

Celata, G. P., 1991, A Review of Recent Experiments and Predictive Aspects of Burnout at Very High Fluxes, Proc. Int. Conf. on Multiphase Flow, Tsukuba, Japan, September. (5)... 

In terms of contrast, Pluronic micelles have a much more higher contrast using SANS (with D20 as a solvent) than with SAXS. It is illustrated in figure 5, where the SANS and SAXS curves in absolute units are compared for the same sample, micelles of P123 in pure D20 at 40°C and at a volume fraction of 2.6 %. The absolute intensity of the SANS curve is about 103 times greater than the SAXS ones. The maximal flux on the D22 experiment is about 10s neutrons/s. Then, in order to perform kinetics experiments with SAXS, with a temporal resolution equal or better than 30 s, the high flux of a synchrotron source (10nphotons/s or more) is needed. 

The discovery of fermium (also einsteinium) was not the result of very carefully planned experiments, as in the cases of the other trans uranium elements, bill fermiuni and einsteinium were found in Ihe debris of an atomic weapon lest in the Pacific in November 1952. Researchers, using the Oak Ridge High Flux Isotope Reactor (HFIR) which produced 3.2-hour " Fm. determined ihe magnetic moment of the atomic ground state of the neutral fermium atom with a modified atomic beam magnetic resonance... 

The study of the 0 decay of 0.59s 145Cs was conducted at the TRISTAN mass separator on-line to the high flux reactor at BNL. A detailed description of the TRISTAN facility can be found in reference [GIL81]. The radioactive samples were produced by fissioning a uranium target integrated in a positive surface ionization source.[PI084] In this experiment, the usual Re surface ionizer was replaced with a Ta ionizer. The lower work function of Ta ensured no independent production of Ba from the ion source at a low power operation ( 1200°C). 

Rare-gas samples exist only at cryogenic temperatures and most of the optical spectroscopy of electronic processes should be done in the vacuum ultraviolet. Making experiments requires an indispensable combination of liquid-helium equipment with windowless VUV-spectroscopic devices and synchrotron radiation as a photon source. To study the electronic excitation energy pathways and a variety of subthreshold inelastic processes, we used the complimentary advantages of cathodoluminescence (possibility to vary the excitation depth beneath the sample surface), photoluminescence (selective-state excitation by synchrotron radiation at high-flux SUPERLUMI-station at HASYLAB, DESY, Hamburg) and... 

High pressure drop causes disruptions to the system hydraulics. Because of the high pressure drop, the lead membranes tend to operate at very high fluxes while the lag membranes operate at low flux. This increases the rate of membrane fouling for both the lead and lag membranes. Lead membranes foul faster because more water is forced to the membrane module faster and the rate of contaminant accumulation in the boundary layer on the membrane surface increases. The lag membranes, on the other hand, experience low flows since most of the water is removed through... 

A similar measurement, based on molecular spectroscopy, has been made with a pre-heated test limiter in TEXTOR [59,60]. This case, with high flux densities, also shows a transition from molecules to atoms with increasing surface temperature as indicated also in Fig. 1.11. Compared to the beam experiments, the transition temperature is shifted by some 100 K. 

Initially the molybdenum fluxes in [55] measured via atomic Mo-lines (379.8 nm, 386.4 nm and 390.3 nm) led to unreasonably high flux values. This was the case because for the calculation of the respective excitation rates the formula of van Regemorter was used [56], as these lines are optically coupled to the ground state (resonance lines). Therefore, experiments were performed to measure the excitation and ionization rates directly both in a linear plasma machine [57] and in a crossed beam experiment with a thermal molybdenum emitter [58], The results can be seen in Fig. 6.17 and show that the experimental values for excitation are about a factor of 5 larger than those from the van Regemorter formula, which leads to a reduction of the flux by the same order according to the smaller S/XB. More refined R-Matrix calculations have later confirmed the same factor and are included in Fig. 6.3. 

A pronounced effect of atomic hydrogen on the deposition rate was found in experiments using quantified radical-beam sources [94]. The sticking coefficient of methyl radicals can be enhanced by about two orders of magnitude if the surface is activated by a sufficiently high flux of atomic hydrogen (of the order of 1019 H/m2 s). 

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