Arbeiter, F.

Klimenko, D.

Pasler, V.

Schlindwein, G.

von der Weth, A.

Zinn, K.

English

Weth, A. von der

KITopen

KIT – The Research University in the Helmholtz Association A. von der Weth *, F. Arbeiter, D. Klimenko, V. Pasler,  G. Schlindwein, K. ZinnKarlsruhe Institut of Technology, Institut für Neutronenphysik und Reaktortechnik, Hermann-von-Helmholzplatz 1 76344 Eggenstein-Leopoldshafen, GermanyFig 4: Eq.(3) is a nonlinear transcendentequation with three variables. Is is solved by aB&B algorithm which compares two possiblesolutions, choosing the better one lower χ² .Fig 5: B&B could use only three steps. But badinitial values and numerical problems (shape ofχ² is parameter space) are forcing a fourth stepholding constant the steady state.Fig 9: Result of the Q-PETE analysis..Results with continues lines are using theTSF, dashed lines are results without TSF.Fig 8: Countermeasure against inter diffusion duringtransport. The small graphics show original signal by blue line,distorted signal by red. Large graphics shows by blue signal ofpure Ar controler and by red that of the calbration gas controler .Green the desired QMS signal.Fig 7:´Result of B&B algorithm optimizationprocedure. All here displayed solutions ownan error less than 10-4. Tolerance is aparameter how fine the variables are treated.Methodology to evaluate hydrogen isotopes permeabilities and diffusivities from experiments with a purged permeator setupThe Q-PETE (Hydrogen Permeation and Transport Experiment)at KIT is set up to investigate hydrogen isotopes permeationthrough structural materialswith specific relevance to the HCPB (helium cooled pebble bed) DEMO blanket breeder zone. The experiment therefore consi ts of two purged chambersseparated by a permeation membrane (made of Eurofer or othersteels of interest). The permeated and purged hydrogen is detected (time resolved) with amass spectrometer. Central objective is the direct determination of material data. The determination of permeation parameters like diffusivity and Sieverts’constants is usually performed by modelling experimental results with a solution of a differential equation, 2nd Fick´s law applied to a flat membrane.Mostly permeation disk or gas release experiments (withoutpurge, measuring the pressure rise) were performed in the past, and according analysismethods were applied.This contribution will introduce necessary methods for purged permeation experiment analysis: A self-developed branch and bound(B&B) algorithm – least square fit algorithm- consisting of super cycles each with four steps which will calculate the desired diffusion and Sieverts’ constant.Signal distortion due to the residence time distribution ofthe measured gas between the permeation chamber and the analysis station, by re-transformationwith a so-called Time Spread Function (TSF), is presented.Contact: axel.vonderweth@kit.edu

Methodology to evaluate hydrogen isotopes permeabilities and diffusivities from experiments with a purged permeator setup

https://publikationen.bibliothek.kit.edu/1000076469/4822122

Methodology to evaluate hydrogen isotopes permeabilities and diffusivities from experiments with a purged permeator setup

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