相关论文: Compound cryopump for fusion reactors
A novel two-stage helium buffer gas cooled beam source is introduced. The properties of the molecular beams produced from this source are investigated theoretically using the CaF as a test molecule. The gas-phase molecules are first…
Deuterated molecules are important chemical tracers of prestellar and protostellar cores. Up to now, the titular reaction has been assumed to contribute to the generation of these deuterated molecules. We have measured the merged-beams rate…
Novel methods are presented in this initial study for the fusion of GPU kernels in the artificial compressibility method (ACM), using tensor product elements with constant Jacobians and flux reconstruction. This is made possible through the…
We have developed low temperature part of an ultra high vacuum scanning probe microscope (UHV-SPM) working at variable temperature within the range from 20 K to 700 K. To achieve the required temperature range, a flow cooling system using…
Two first-principles simulation techniques, path integral Monte Carlo (PIMC) and density functional molecular dynamics (DFT-MD), are applied to study hot, dense helium in the density-temperature range of 0.387 - 5.35 g/cc and 500 K -…
We propose a highly efficient and fast method of translational cooling for high-angular-momentum atoms. Optical pumping and stimulated transitions, combined with magnetic forces, can be used to compress phase-space density, and the…
We investigate deuterium chemistry coupled with the nuclear spin-state chemistry of H$_2$ and H$_3^+$ in protoplanetary disks. Multiple paths of deuterium fractionation are found; exchange reactions with D atoms, such as HCO$^+$ + D, are…
We study the thermophysical properties of dense helium plasmas by using quantum molecular dynamics and orbital-free molecular dynamics simulations, where densities are considered from 400 to 800 g/cm$^{3}$ and temperatures up to 800 eV.…
The present research work is focused on the effect of activation procedure on the hydrogen absorption-desorption properties of new rare earth transition metal compound based on Sm(Co0.6Fe0.2Zr0.16B0.04)7.5 composition. Crystal structure and…
At low magnetic field, metastability exchange optical pumping of helium-3 is known to provide high nuclear polarizations for pressures around 1 mbar. In a recent paper, we demonstrated that operating at 1.5 T can significantly improve the…
Reaching high densities is a key step towards cold-collision experiments with polyatomic molecules. We use a cryofuge to load up to 2$\times10^7$ CH$_3$F molecules into a box-like electric trap, achieving densities up to 10$^7$/cm$^3$ at…
Magneto-Inertial Fusion Technology Inc. has been working on a Z-pinch concept where a high atomic number liner is compressing a fusion fuel (deuterium-deuterium, or deuterium-tritium) target. The viability of this so called Staged Z-pinch…
The model of hydrogen migration and of the reactions of hydrogen atoms with electrically active impurity, developed earlier, has been applied to simulate hydrogen diffusion and passivation process during plasma deuteration of silicon…
Tritium plays a critical role in nuclear fusion power plant designs and dryer beds are an essential tool for managing tritiated water vapor. A series of tests were performed to investigate the ability of a saturated dryer to preferentially…
Using a diffusion Monte Carlo (DMC) technique, we calculated the phase diagram of 3He adsorbed on a first solid layer of a molecular hydrogen isotope (H2,HD and D2) on top of graphite. The results are qualitatively similar in all cases: a…
A concentration-saturated helium mixture at the melting pressure consists of two liquid phases and one or two solid phases. The equilibrium system is univariant, whose properties depend uniquely on temperature. Four coexisting phases can…
We report on the detection of deuterated molecular hydrogen, HD, at $z = 0.18$. HD and H$_{\rm 2}$ are detected in HST/COS data of a low metallicity ($Z \sim 0.07Z_\odot$) damped Ly$\alpha$ system at $z = 0.18562$ toward QSO B0120$-$28,…
We generate an atomic beam of titanium (Ti) using a "Ti-ball" Ti-sublimation pump, which is a common getter pump used in ultrahigh vacuum (UHV) systems. We show that the sublimated atomic beam can be optically pumped into the metastable…
Superfluid helium's low-loss dielectric properties, excellent thermal conductivity, and unique collective excitations make it an attractive candidate to incorporate into superconducting qubit systems. We controllably immerse a…
The interplay between electron correlation and nuclear quantum effects makes our understanding of elemental hydrogen a formidable challenge. Here, we present the phase diagram of hydrogen and deuterium at low temperatures and high-pressure…