SRF2013 - List of Authors (Roach, W.M.)

Paper

Title

Page

Proof of Concept Thin Films and Multilayers Toward Enhanced Field Gradients in SRF Cavities

782

R.A. Lukaszew, D. Beringer, W.M. Roach
The College of William and Mary, Williamsburg, USA
G.V. Eremeev, A-M. Valente-Feliciano
JLAB, Newport News, Virginia, USA
C.E. Reece
JLab, Newport News, Virginia, USA
X. Xi
TU, Philadelphia, USA

Funding: Defense Threat Reduction Agency (DTRA)
Due to the very shallow penetration depth of the RF fields, SRF properties are inherently a surface phenomenon involving a material thickness of less than 1 micron thus opening up the possibility of using thin film coatings to achieve a desired performance. The challenge has been to understand the dependence of the SRF properties on the detailed characteristics of real surfaces and then to employ appropriate techniques to tailor these surface properties for greatest benefit. Our aim is to achieve gradients >100 MV/m and no simple material is known to be capable of sustaining this performance. A theoretical framework has been proposed which could yield such behavior [1] and it requires creation of thin film layered structures. I will present our systematic studies on such proof-of-principle samples. Our overarching goal has been to build a basic understanding of key nano-scale film growth parameters for materials that show promise for SRF cavity multilayer coatings and to demonstrate the ability to elevate the barrier for vortex entry in such layered structures above the bulk value of Hc1 for type-II superconductors and thus to sustain higher accelerating fields.
[1]. A. Gurevich, Appl. Phys. Lett. 88, 012511 (2006).

Slides WEIOB02 [15.612 MB]

Paper	Title	Page
WEIOB02	Proof of Concept Thin Films and Multilayers Toward Enhanced Field Gradients in SRF Cavities	782
	R.A. Lukaszew, D. Beringer, W.M. Roach The College of William and Mary, Williamsburg, USA G.V. Eremeev, A-M. Valente-Feliciano JLAB, Newport News, Virginia, USA C.E. Reece JLab, Newport News, Virginia, USA X. Xi TU, Philadelphia, USA
	Funding: Defense Threat Reduction Agency (DTRA) Due to the very shallow penetration depth of the RF fields, SRF properties are inherently a surface phenomenon involving a material thickness of less than 1 micron thus opening up the possibility of using thin film coatings to achieve a desired performance. The challenge has been to understand the dependence of the SRF properties on the detailed characteristics of real surfaces and then to employ appropriate techniques to tailor these surface properties for greatest benefit. Our aim is to achieve gradients >100 MV/m and no simple material is known to be capable of sustaining this performance. A theoretical framework has been proposed which could yield such behavior [1] and it requires creation of thin film layered structures. I will present our systematic studies on such proof-of-principle samples. Our overarching goal has been to build a basic understanding of key nano-scale film growth parameters for materials that show promise for SRF cavity multilayer coatings and to demonstrate the ability to elevate the barrier for vortex entry in such layered structures above the bulk value of Hc1 for type-II superconductors and thus to sustain higher accelerating fields. [1]. A. Gurevich, Appl. Phys. Lett. 88, 012511 (2006).
	Slides WEIOB02 [15.612 MB]