Samples for 3rd Harmonic Magnetometry Assessment of NbTiN-Based SIS Structures

Conference · Sun May 01 04:00:00 EDT 2022

DOI:https://doi.org/10.18429/JACoW-SRF2021-SUPTEV016· OSTI ID:1905274

Beverstock, D. R. ^[1]; Delayen, J. R. ^[2]; Senevirathne, I. H. ^[2]; Spradlin, J. K. ^[1]; Valente-Feliciano, A. M. ^[1]; Antoine, C. Z. ^[3]; Manos, D. ^[4]

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1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Old Dominion Univ., Norfolk, VA (United States)
3. CEA-IRFU, Gif-sur-Yvette, France
4. College of William and Mary, Williamsburg, VA (United States)

In the quest for alternative superconducting materials to bring accelerator cavity performance beyond the bulk niobium (Nb) intrinsic limits, a promising concept uses superconductor-insulator-superconductor (SIS) thin film structures that allows magnetic flux penetration in accelerator cavities to higher fields[1]. NbTiN is a candidate superconductor for such structures. We have demonstrated high quality NbTiN and AlN deposited by reactive direct current magnetron sputtering (DCMS), both for individual layers and multilayers. Interface quality has been assessed for bi-layer stacks with various NbTiN and AlN thicknesses from 250 and 30 nm down to 3 and 1 nm. These SIS structures show continued sharp interfaces with total roughness under 2 nm. The Hfp enhancement of the films will be examined with a 3rd harmonic magnetometry instrument. The system is being designed and built in a continuing collaboration with CEA Saclay. It can measure 25 to 50 mm samples on a temperature controlled stage. This contribution presents an overview of design of the 3rd harmonic magnetometry instrument and the assessment of standalone films and multilayer nanostructures.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1905274
• Report Number(s): JLAB-ACC-21-3442; DOE/OR/23177-5256
• Country of Publication: United States
• Language: English