• Achieving ultrahigh vacuum in an unbaked chamber with glow discharge conditioning

• # Fulltext

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

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

• # Pramana – Journal of Physics

Volume 96, 2022
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019