Buffer gas

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

Emittance improvement of the electron cyclotron resonance high intensity light ion source proton beam by gas injection in the low energy beam transport

Abstract: SILHI is the ECR high intensity light ion source studied in France at C.E.A. Saclay. This is the source for the injector of the high intensity proton injector prototype developed by a CNRS-IN2P3 collaboration. 80 mA at 95 keV beams with a rms normalized r–r′ emittance lower than 0.3 π mm mrad and a proton fraction better than 85% are currently produced. Recently, it has been found that the injection in the low energy beam transport of a buffer gas had a strong effect on the emittance measured 1 m downstream of the focusing solenoid. By adding several gases (H2, N2, Ar, Kr), improvements as great as a factor of 3 have been observed. The emittance has been measured by means of an r–r′ emittance measurement unit equipped with a sampling hole and a wire profile monitor, both moving across the beam. Simultaneously, the space charge compensation factor is measured using a four-grid analyzer unit. In this article all results of these experiments are presented and discussed. A first explanation of the emittance r...

Light-induced potassium desorption from polydimethylsiloxane film

Abstract: Potassium photoejection from polydimethylsiloxane surfaces has been observed and analyzed in detail. By diode laser absorption spectroscopy the K concentration in a sealed measurement cell without buffer gas has been monitored as a function of the environment variables, like temperature, flooding light wavelength and power. The dynamic evolution of the process has been measured too, showing differences compared to previous measurements with different alkali-metal atoms. Saturation spectroscopy on the K D1 line has been performed at room temperature by taking advantage of this phenomenon. PACS. 34.50.Dy Interactions of atoms and molecules with surfaces; photon and electron emission; neu- tralization of ions - 42.50.Ct Quantum description of interaction of light and matter; related experiments - 68.43.Tj Photon stimulated desorption

Gas recovery unit

Abstract: Provided is a gas recovery unit which is more efficient in its recovery and less expensive to run. The gas recovery unit comprises a CVD device, an exhaust gas recovery part and an exhaust gas purification part. The exhaust gas recovery part is constructed so as to have an inert gas reservoir part capable of accommodating liquid nitrogen, to have an exhaust gas supply part for supplying an exhaust gas to said inert gas reservoir part so that it can be brought in gasliquid contact with the liquid nitrogen, and to have a recovered and liquefied gas discharge part for discharging the recovered and liquefied gas which has been liquefied in the inert gas reservoir part. The exhaust gas purification part is constructed so as to have a recovered and liquefied gas reception part, an evaporator and a condenser for carrying out a heat exchange between said liquid nitrogen and the recovered and liquefied gas which has been evaporated, and cleaning gas recovery parts, and to have a cooling inert gas discharge part, wherein the cooling inert gas discharge part is connected to the inert gas supply path.

Nonlinear effects in pulse propagation through Doppler-broadened closed-loop atomic media

Abstract: Nonlinear effects in pulse propagation through a medium consisting of four-level double-$\ensuremath{\Lambda}$-type systems are studied theoretically. We apply three continuous-wave driving fields and a pulsed probe field such that they form a closed interaction loop. Due to the closed loop and the finite frequency width of the probe pulses, the multiphoton resonance condition cannot be fulfilled, such that a time-dependent analysis is required. By identifying the different underlying physical processes we determine the parts of the solution relevant to calculate the linear and nonlinear response of the system. We find that the system can exhibit a strong intensity-dependent refractive index with small absorption over a range of several natural linewidths. For a realistic example we include Doppler and pressure broadening and calculate the nonlinear self-phase modulation in a gas cell with sodium vapor and argon buffer gas. We find that a self-phase modulation of $\ensuremath{\pi}$ is achieved after the propagation of a few centimeters through the medium while the absorption and pulse shape distortion in the corresponding spectral range is small.