A cryogenic supersonic nozzle apparatus to study homogeneous nucleation of Ar and other simple molecules

Sinha, Somnath; Laksmono, Hartawan; Wyslouzil, Barbara E.
November 2008
Review of Scientific Instruments;Nov2008, Vol. 79 Issue 11, p114101
Academic Journal
A correlation electron cyclotron emission (CECE) diagnostic has been used to measure local, turbulent fluctuations of the electron temperature in the core of DIII-D plasmas. This paper describes the hardware and testing of the CECE diagnostic and highlights the importance of measurements of multifield fluctuation profiles for the testing and validation of nonlinear gyrokinetic codes. The process of testing and validating such codes is critical for extrapolation to next-step fusion devices. For the first time, the radial profiles of electron temperature and density fluctuations are compared to nonlinear gyrokinetic simulations. The CECE diagnostic at DIII-D uses correlation radiometry to measure the rms amplitude and spectrum of the electron temperature fluctuations. Gaussian optics are used to produce a poloidal spot size with wo∼1.75 cm in the plasma. The intermediate frequency filters and the natural linewidth of the EC emission determine the radial resolution of the CECE diagnostic, which can be less than 1 cm. Wavenumbers resolved by the CECE diagnostic are kθ≤1.8 cm-1 and kr≤4 cm-1, relevant for studies of long-wavelength turbulence associated with the trapped electron mode and the ion temperature gradient mode. In neutral beam heated L-mode plasmas, core electron temperature fluctuations in the region 0.5


Related Articles

  • Argon nucleation in a cryogenic supersonic nozzle. Sinha, Somnath; Bhabhe, Ashutosh; Laksmono, Hartawan; Wölk, Judith; Strey, Reinhard; Wyslouzil, Barbara // Journal of Chemical Physics;2/14/2010, Vol. 132 Issue 6, p064304 

    We have measured pressures p and temperatures T corresponding to the maximum nucleation rate of argon in a cryogenic supersonic nozzle apparatus where the estimated nucleation rates are J=1017±1 cm-3 s-1. As T increases from 34 to 53 K, p increases from 0.47 to 8 kPa. Under these conditions,...

  • Onset of SF[sub 6] clustering in steady supersonic Laval nozzle flow. Okada, Y.; Ashimine, K.; Takeuchi, K. // Applied Physics B: Lasers & Optics;2000, Vol. 70 Issue 1, p117 

    Abstract. SF[sub 6} clustering (3%-6% in molar fraction) by homogeneous nucleation in argon was experimentally studied in a steady-state-flow supersonic Laval nozzle. The onset of clustering was detected by FT-IR spectroscopy. Measurements of the static pressure in the nozzle, together with the...

  • Nitrogen nucleation in a cryogenic supersonic nozzle. Bhabhe, Ashutosh; Wyslouzil, Barbara // Journal of Chemical Physics;12/28/2011, Vol. 135 Issue 24, p244311 

    We follow the vapor-liquid phase transition of N2 in a cryogenic supersonic nozzle apparatus using static pressure measurements. Under our operating conditions, condensation always occurs well below the triple point. Mean field kinetic nucleation theory (MKNT) does a better job of predicting the...

  • Composition and heavy component enrichment of free Ar-Kr and Kr-Xe clusters. Danilchenko, A. G.; Kovalenko, S. I.; Konotop, A. P.; Samovarov, V. N. // Low Temperature Physics;Jun2011, Vol. 37 Issue 6, p532 

    The composition of free Ar-Kr and Kr-Xe clusters produced by condensation of supersonic jets of gaseous mixtures with different amounts of krypton and xenon are studied in detail by electron diffraction for the first time. Analytic relationships are derived between the concentration of the heavy...

  • Homogeneous nucleation and droplet growth in supersaturated argon vapor: The cryogenic nucleation pulse chamber. Fladerer, Alexander; Strey, Reinhard // Journal of Chemical Physics;4/28/2006, Vol. 124 Issue 16, p164710 

    We built a cryogenic nucleation pulse chamber for measuring homogeneous nucleation rates of argon. First measurements show that the growth rate of argon droplets at nucleation conditions is rather high so that nucleation and growth could not yet be decoupled. Nevertheless, the experiments permit...

  • Dishing About Plate Heat Exchangers. Payette, Joseph // Process Cooling & Equipment;Jul/Aug2002, p31 

    Provides information on standard gasketed plate-and-frame heat exchangers. Components of the plate heat exchanger; Variables that can be used to specify a plate heat exchanger; Advantages to using plate heat exchangers.

  • Development of small 2K cryocooler (II)-high efficient and low pressure drop heat exchanger-. Nagai, H.; Sato, A.; Nimori, S.; Numasawa, K.; Maeda, M.; Matsumoto, F.; Takahashi, M.; Ohsemochi, K.; Kuriyama, T.; Fujioka, T.; Kitagawa, K.; Okamura, T. // AIP Conference Proceedings;2002, Vol. 613 Issue 1, p1491 

    This paper describes a design and experimental results of a recuperative heat exchanger used in a small 2K cryocooler. High and low pressures for this heat exchanger are about 1.0 MPa and 1.6 kPa respectively. The technical point of this heat exchanger is a low pressure drop in low pressure...

  • Performance of thermal shields of LHD cryostat cooled by gaseous helium with parallel paths. Imagawa, S.; Tamura, H.; Yanagi, N.; Sekiguchi, H.; Mito, T.; Satow, T. // AIP Conference Proceedings;2002, Vol. 613 Issue 1, p1475 

    The Large Helical Device is the largest cryogenic apparatus for a research of fusion plasma. Thermal shields are installed to reduce heat loads to the superconducting coils. Since the total area is very wide, seamless pipes were adopted to reduce the possibility of helium leakage, and parallel...

  • Single-phase helium recooling in a Tevatron spool piece. Klebaner, A. L.; Theilacker, J. C. // AIP Conference Proceedings;2002, Vol. 613 Issue 1, p1437 

    The existing Tevatron spool piece has been upgraded by adding a single-phase to two-phase heat exchanger or recooler. This will enhance the single-phase to two-phase heat transfer and, along with other upgrades, allow for a higher energy The performance of the heat exchanger was predicted...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics