A new cost effective composite getter for application in high-vacuum-multilayer-insulation tank

Abstract H2 is the main residual gas in the chamber of high-vacuum-multilayer-insulation tank (HVMIT) and is adsorbed by the expensive getter PdO. Adsorption characteristics of more cost effective getters (CuO, CuO & 5A and CuO & C) were investigated and adsorption products were analyzed by measuring the pressure decrease in a known volume as function of time using our designed experimental setup. CuO & C was more suitable to adsorb H2 in HVMIT than the other getters investigated. H2 adsorption amount and pumping speed were significantly larger than CuO and CuO & 5A getter systems. Working temperature could be also reduced with respect to these two getter bed, this being advantageous from the operational point of view. Adsorption isotherm was type I as accurately described by Langmuir model. H2 sorption amount was 170.6 mL(stp)/g at equilibrium pressure not higher than 5.8 × 10−2 Pa, saturated sorption amount was 296.4 mL(stp)/g at room temperature, and sorption products were Cu and H2O (g). When adsorption equilibrium was obtained, HVMIT was fed with liquid nitrogen. Interlayer pressure decreased sharply to 5.83 × 10−4 Pa in a stepwise shape for 10 h. This vacuum level is appropriate for ensuring good insulation level in the tank.

[1]  Stephen Poulston,et al.  Surface Oxidation and Reduction of CuO and Cu2O Studied Using XPS and XAES , 1996 .

[2]  B. E. Nieuwenhuys,et al.  The low-temperature reduction of Pd-doped transition metal oxide surfaces with hydrogen , 2003 .

[3]  V. Nemanic,et al.  An overview of methods to suppress hydrogen outgassing rate from austenitic stainless steel with reference to UHV and EXV , 2003 .

[4]  Y. Kudo,et al.  Preparation and reduction kinetics of uniform copper particles from copper(I) oxides with hydrogen , 1992 .

[5]  K. Kilian,et al.  Residual gas analysis in the TOF vacuum system , 2005 .

[6]  Jin-Tae Kim,et al.  Residual gas survey of stainless steel 304 extreme high vacuum chamber with hot cathode ionization gauge , 2008 .

[7]  A. Gu,et al.  How to accurately determine the uptake of hydrogen in carbonaceous materials , 2004 .

[8]  L. Detian,et al.  Applications of non evaporable getter pump in vacuum metrology , 2011 .

[9]  J. Hanson,et al.  Reduction of CuO and Cu2O with H2: H embedding and kinetic effects in the formation of suboxides. , 2003, Journal of the American Chemical Society.

[10]  Y. Zeng,et al.  Experimental investigation on hydrogen adsorption performance of composite adsorbent in the tank with high vacuum multilayer insulation , 2009 .

[11]  Y. Xu,et al.  Effects of electroless nickel on H2, CO, CH4 absorption properties of Zr–V–Fe powder , 2014 .

[12]  Rongshun Wang,et al.  Experimental investigation and theoretical analysis on measurement of hydrogen adsorption in vacuum system , 2010 .

[13]  P della Porta,et al.  Gas problem and gettering in sealed-off vacuum devices , 1996 .

[14]  S. Lowell,et al.  Powder surface area and porosity , 1984 .

[15]  J. Hanson,et al.  Reduction of CuO in H2: In Situ Time-Resolved XRD Studies , 2003 .

[16]  J. Hanson,et al.  Reaction of CuO with hydrogen studied by using synchrotron-based x-ray diffraction , 2004 .

[17]  A. Kaflou,et al.  Effect of rare earth elements on sorption characteristics of nanostructured Zr–Co sintered porous getters , 2015 .

[18]  S. Mentus,et al.  A kinetic study of copper(II) oxide powder reduction with hydrogen, based on thermogravimetry , 2011 .

[19]  R. N. Pease,et al.  THE REDUCTION OF COPPER OXIDE BY HYDROGEN. , 1921 .

[20]  J. Du,et al.  Preparation and hydrogen sorption performance of a modified Zr-C getter , 2008 .

[21]  Hangkyo Jin,et al.  Hydrogen adsorption characteristics of activated carbon , 2007 .