• Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/pram/088/01/0012

    • Keywords

       

      Ultrahigh vacuum; glow discharge conditioning; hydrogen; helium.

    • Abstract

       

      Glow discharge conditioning (GDC) has long been accepted as one of the basic wall conditioning techniques for achieving ultrahigh vacuum in an unbaked chamber. As a part of this fundamental experimental study, a test chamber has been fabricated from stainless steel 304 L with its inner surface electropolished on which a detailed investigation has been carried out. Both helium and hydrogen gases have been employed as discharge cleaning medium. The discharge cleaning was carried out at 0.1 A/m$^{2}$ current density with workingpressure maintained at $1.0 \times 10^{−2}$ mbar. It was experimentally observed that the pump-down time to attain the base pressure $∼10−8$ mbar was reduced by 62% compared to the unbaked chamber being pumped to this ultimate vacuum. The results were similar irrespective of whether the discharge cleaning medium is either hydrogen or helium. It was also experimentally established that a better ultimate vacuum could be achieved as compared to theoretically calculated ultimate vacuum with the help of discharge cleaning.

    • Author Affiliations

       

      ZIAUDDIN KHAN1 PRATIBHA SEMWAL1 KALPESH R DHANANI1 DILIP C RAVAL1 SUBRATA PRADHAN1

      1. Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382 428, India
    • Dates

       
  • Pramana – Journal of Physics | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2021-2022 Indian Academy of Sciences, Bengaluru.