Buffer gas

About: Buffer gas is a research topic. Over the lifetime, 3565 publications have been published within this topic receiving 47283 citations.

Relaxation of Optically Pumped Cesium Atoms by Different Buffer Gases

Abstract: The decay of spin polarization of optically pumped cesium atoms at room temperature in the inert buffer gases helium, neon, and argon, has been investigated at different buffer gas pressures. It has been found that the decay of the spin polarization is not a simple exponential but can be described as the sum of two exponentially decaying modes, which are interpreted as two diffusion modes. The diffusion coefficients for cesium in helium, neon, and argon are found to be 0.37, 0.24, and 0.19 cm2/sec, and the collision depolarization cross sections are 2.5×10—24, 8.4×10—24, and 26×10—24 cm2, respectively.

Quantum-classical molecular dynamics simulation of femtosecond spectroscopy on I2 in inert gases: Mechanisms for the decay of pump–probe signals

Abstract: A mixed quantum–classical method is proposed to describe the dynamical behavior of a diatomic molecule in a gas environment. The vibrational coordinate is treated quantum-mechanically and all other degrees of freedom classically. Within the present approach the classical equations for the rotational motion have no singularities. A symplectic, energy conserving and time-reversible algorithm is used for the propagation. As an application we treat the dynamics of I2 molecules excited by femtosecond laser pulses moving in collision-free and high pressure rare-gas environments. For freely rotating I2 molecules, the thermal average over rotational states leads to the decay of the pump–probe signal. For I2 in inert gases, we show that dephasing by collisions with the buffer gas is a weak effect in comparison with the decay of the signal due to the anharmonicity of the potential energy curve. Therefore the oscillating structure of the pump–probe signals depends weakly on the mass and the pressure of the solvent, ...

Apparatus and method for the removal of impurity gases from inert gases and the ensurance of extremely low levels of hydrogen

Abstract: An apparatus is described for the removal of impurity gases such as O₂, CH₄, CO, CO₂ and H₂ from impure inert gases such as rare gases and N₂. The apparatus comprises an impure inert gas inlet, a housing containing first and second gas sorbing materials and a purified gas outlet. The first gas sorbing material may be a Zr-V-Fe getter alloy if the gas to be purified is a rare gas, whereas it may be a Zr-Fe alloy if the gas to be purified is N₂. The second gas sorbing material is a Zr-Al alloy which ensures that the purified inert gas has an extremely low level of hydrogen. A process for the removal of impurity gases from inert gases and ensuring an extremely low level of hydrogen in the purified gas is also described.

Two-step formation of hydrocarbon-based polymer film

Abstract: A method of forming a surface-treated hydrocarbon-based polymer film includes: supplying a hydrocarbon gas as a source gas, and an inert gas, and applying RF power to generate a plasma and form a hydrocarbon-based principal film on a substrate; and without extinguishing a plasma, changing flow of the hydrocarbon gas and the inert gas by continuously decreasing a flow ratio of the hydrocarbon gas to the inert gas with time to treat a surface of the principal film on the substrate