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Abstract: A saturation vapor pressure equation, p(T), is an essential component in the 3He state equation currently under development. The state equation is valid over the range 0.01–20K with pressures from 0 to the melting pressure or 15MPa. The vapor pressure equation consequently must be valid from 0.01K to the critical temperature. This paper surveys available 3He critical temperature and pressure measurements, leading to new recommended critical values of 3.3157K and 114603.91Pa. The ITS-90 temperature scale is defined by the 3He vapor pressure from 0.65 to 3.2K. A new vapor pressure equation is developed for the interval from the upper end of the T 90 scale to this newly defined critical point, employing a mathematical form in which the second derivative d2 p/dT 2 diverges in agreement with scaling laws at the critical point. Below 0.65K, an empirical vapor pressure expression is adopted, consistent with a theoretical expression valid in the limit T →0. These two new components are fitted to be piecewise continuous with the EPT-76 p(T) scale rather than the ITS-90 T(p) scale between 0.65 and 3.2K. Probable deviations between this vapor pressure scale and PLTS-2000 melting pressure–temperature scale are recognized, but not reconciled. [Copyright &y& Elsevier]

Highlights • CFD model for simulating LN2 in a tank with baffle under microgravity is developed. • Effect of gravity, fill level, distance, angle and gap on pressure rise is discussed. • A 2nd order correlation between liquid fraction and pressure rise is proposed. • A structure is proposed to achieve high performance of pressure suppression. Abstract Researches on the impact of baffles on sloshing suppression of two-phase fluids in storage tanks have been widely conducted in literature, particularly at normal gravity. However, few studies focused on the effect of the baffles on self-pressurization and thermal stratification of the fluids in containers. This paper uses Volume of Fluid (VOF) method to simulate thermal behavior of cryogenics in tanks with different baffle structures in microgravity environment. Groups of gravity levels, fill levels and baffle configurations (distances, angles and gaps) are investigated. Up to 54% reduction in pressurization rate was observed by optimizing the baffle settings, which is an attractive improvement for missions of long term storage of cryogen on orbit. [ABSTRACT FROM AUTHOR]

Abstract: Roughness development is one of the most often addressed issues in the secondary ion mass spectrometry (SIMS) ultra-shallow depth profiling. The effect of oxygen flooding pressure on the roughness development has been investigated under the bombardment of 500eV O2 + beam with simultaneous sample rotation. Oxygen flooding had two competing effects on the surface roughening, i.e., enhancement of initiating roughening and suppression of roughening development, which were suggested to be described by the onset depth z on and transient width w tr of surface roughening. Both z on and w tr decreased as oxygen flooding pressure increased. As the result, surface roughening was most pronounced at the intermediate pressure from 4.4E−5Pa to 5.8E−5Pa. The surface roughening is negligible while without flooding or with flooding at the saturated pressure. No flooding is preferable for depth profiling ultra-shallow B implantation because of the better B profile shape and short analysis time. [Copyright &y& Elsevier]