Buffer gas

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

Optimized Condition for Buffer Gas in Optical-Pumped Magnetometer Operated at Room Temperature

Abstract: The optimal buffer-gas condition for achieving low noise in room temperature optical-pumped magnetometers (OPMs) was determined. To find this optimal condition, various buffer gases (helium, neon, argon, and nitrogen) filled in cesium cells at pressures of 1, 10, 50, 300, or 1000 Torr were tested. Magnetic-resonance signal was detected by sweeping rf frequency, and maximum intensity (Imax) and line width (Δf) in the magnetic-resonance spectra were measured. As an appropriate figure of merit for OPMs, the "α value" (i.e., Imax/Δf) is defined. It was found that the α value of the cells decreased as gas pressure increased. The α value obtained from the cell filled with neon gas (at 1 Torr) at optimal rf field of 50 nT was the largest. It was inferred from these results that the spin-destruction collision between cesium atoms and the buffer gas has a significant influence on the α value.

Effects of Helium Buffer Gas Atoms on the Atomic Hydrogen Hyperfine Frequency

Abstract: Calculations are made for the pressure, mass, and temperature dependence of the atomic hydrogen hyperfine frequency shift arising from the perturbing influence of helium buffer gas atoms. The calculated fractional pressure shift is found to be +1.73×10—9 mm Hg—1 compared with the experimental value of +3.7×10—9 mm Hg—1. From the standpoint of the calculation this discrepency may be related to a failure of the simple wave function employed to adequately characterize the unpaired electron spin density at the hydrogen nucleus. The results of the calculations for the temperature variation and mass dependence indicate that these are very small effects. The form of the mass dependent quantum statistical correction, used to elucidate the mass effect, suggests that the relatively large variations experimentally observed with other buffer gases, due to hydrogen isotope variation, are in error.Finally, a calculation is made for the pressure shift from a kinetic theory point of view and the result obtained (+1.79×10...

Enhanced cooling of hydrogen by a buffer gas of alkali-metal atoms

Abstract: We consider the possibility of enhanced cooling of hydrogen atoms by a buffer gas of alkali-metal atoms Na, K, Rb, and Cs. Ultracold elastic collision cross sections for the Na-H and Rb-H purely spin-polarized pairs are found to be 640 and 860 times larger than that for the H-H pair, respectively. From an analysis of the techniques of production of ultracold sodium and rubidium samples, it seems feasible that the critical conditions for Bose-Einstein condensation of hydrogen could be achieved already at the stage of optical cooling of the sodium or rubidium buffer gas.

Sub-natural $N$-type Resonance in Cesium Atomic Vapor: splitting in magnetic fields

Abstract: The sub-natural-width $N$-type resonance in {\Lambda}-system, on the $D_2$ line of Cs atoms is studied for the first time in the presence of a buffer gas (neon) and the radiations of two continuous narrow band diode lasers. $L$ = 1 cm long cell is used to investigate $N$-type process. The $N$-type resonance in a magnetic field for $^{133}$Cs atoms is shown to split into seven or eight components, depending on the magnetic field and laser radiation directions. The results obtained indicate that levels $F_g$ = 3, 4 are initial and final in the N resonance formation. The experimental results with magnetic field agree well with the theoretical curves.

Faraday anomalous dispersion optical filter with a single transmission peak using a buffer-gas-filled rubidium cell.

Abstract: A Faraday anomalous dispersion optical filter (FADOF) with a single transmission peak is achieved by using a buffer-gas (argon, 2 Torr)-filled rubidium cell. At room temperature, the transmission is 0.2% and the bandwidth of the transmission peak is 0.65 GHz. At a temperature of 63° C, the transmission rises to a maximum of 30.6%, with a bandwidth of 1.41 GHz. This FADOF may replace the use of interference filters or virtually imaged phased arrays in imaging modalities.