ANALYZING SURFACE ROUGHNESS DEPENDENCE OF LINEAR RF LOSSES

Conference · Sat Sep 01 04:00:00 EDT 2012

OSTI ID:1088989

Reece, Charles E. ^[1]; Kelley, Michael J. ^[2]; Xu, Chen ^[2]

---

1. JLAB
2. JLAB, W& M College

Topographic structure on Superconductivity Radio Frequency (SRF) surfaces can contribute additional cavity RF losses describable in terms of surface RF reflectivity and absorption indices of wave scattering theory. At isotropic homogeneous extent, Power Spectrum Density (PSD) of roughness is introduced and quantifies the random surface topographic structure. PSD obtained from different surface treatments of niobium, such Buffered Chemical Polishing (BCP), Electropolishing (EP), Nano-Mechanical Polishing (NMP) and Barrel Centrifugal Polishing (CBP) are compared. A perturbation model is utilized to calculate the additional rough surface RF losses based on PSD statistical analysis. This model will not consider that superconductor becomes normal conducting at fields higher than transition field. One can calculate the RF power dissipation ratio between rough surface and ideal smooth surface within this field range from linear loss mechanisms.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE SC Office of Basic Energy Sciences (SC-22)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1088989
• Report Number(s): JLAB-ACC-12-1699; DOE/OR/23177-2533
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS