Title: Coaxial Energetic Deposition of thin films
Author: Mahadevan Krishnan
Institution: Alameda Applied Sciences Corporation
Abstract: Mahadevan Krishnan, Irfan Irfan, Steven Chapman, Katherine Velas and Matt Worstell, Alameda Applied Sciences Corporation, San Leandro, CA 94577, USA
AASC has been studying thin film coating of Nb on coupon substrates as well as on1300MHz RF cells. At the last Thinfilm workshop in Padua, we reported on high RRR measurements and good crystallinity in Nb films coated onto crystal substrates such as a-sapphire, MgO and also on polished Copper coupons. Since then, we have coated several 1300MHz RF cells provided to us and tested by LANL, ANL and JLab. The Qo vs. E measurements suggest that better surface preparation is a must for high quality RF performance. Future work will coat Copper cells with different surface preparation (centrifugal barrel polishing and EP) and try to improve upon our preliminary results. Results from Nb films coated on to Al6061 coupons are encouraging and motivate coating of a barrel polished Aluminum RF cell. Recently AASC has embarked upon two new thinfilm coating projects: Nb on stainless steel bellows for SRF accelerators and Cu films on stainless steel tubes for high power RF Couplers. We are also collaborating with CERN to coat a Cu disk of a quadrupole resonator with Nb, for RF tests at high fields. This talk will provide details of all of these ongoing activities, all of which are supported by the US Department of Energy via SBIR contracts.
This research is supported at AASC by DOE Grants: #DE-SC0011371, DE-SC0011294, DE-SC0007678 and DE-SC0009581.