Optimization of Chemical Etching Process in Niobium Cavities

Authors

Mohamed B. Trabia, University of Nevada, Las VegasFollow
William Culbreth, University of Nevada, Las VegasFollow
Satishkumar Subramanian, University of Nevada, Las VegasFollow
Tsuyoshi Tajima, Los Alamos National LaboratoryFollow

Document Type

Conference Proceeding

Publication Date

9-28-2004

Publication Title

2004 ASME Design Engineering Technical Conferences and Computers and Information in Engineering Conference

Publisher

American Society of Mechanical Engineers

First page number:

149

Last page number:

157

Abstract

Superconducting niobium cavities are important components of linear accelerators. Buffered chemical polishing (bcp) on the inner surface of the cavity is a standard procedure to improve its performance. The quality of bcp, however, has not been optimized well in terms of the uniformity of surface smoothness. A finite element computational fluid dynamics (cfd) model was developed to simulate the chemical etching process inside the cavity. The analysis confirmed the observation of other researchers that the sections closer to the axis of the cavity received more etching than other regions. A baffle was used by lanl personnel to direct the flow of the etching fluid toward the walls of the cavity. A new baffle design was tined using optimization techniques. The redesigned baffle significantly improves the performance of the etching process. To verify these results an experimental setup for flow visualization was created. The setup consists of a high speed, high resolution ccd camera. The camera is positioned by a computer-controlled traversing mechanism. A dye injecting arrangement is used for tracking the fluid path. Experimental results are in general agreement with computational findings.

Keywords

Computational fluid dynamics; Etching; Grinding and polishing; Holes; Linear accelerators; Niobium; Surfaces

Disciplines

Fluid Dynamics | Materials Science and Engineering | Mechanical Engineering | Nuclear Engineering

Language

English

Comments

Conference held: Salt Lake City, Utah, USA, September 28–October 2, 2004

Permissions

Use Find in Your Library, contact the author, or interlibrary loan to garner a copy of the item. Publisher policy does not allow archiving the final published version. If a post-print (author's peer-reviewed manuscript) is allowed and available, or publisher policy changes, the item will be deposited.

Repository Citation

Trabia, M. B., Culbreth, W., Subramanian, S., Tajima, T. (2004). Optimization of Chemical Etching Process in Niobium Cavities. 2004 ASME Design Engineering Technical Conferences and Computers and Information in Engineering Conference 149-157. American Society of Mechanical Engineers.