Prof.
Xiaoxing Xi
(Temple University)
09/10/2018, 09:00
Other superconducting materials beyond niobium
MgB2 is a promising superconductor to replace Nb for SRF cavities. Clean MgB2 thin films have a low residual resistivity (<0.1 µΩcm) and a high Tc of 40 K, promising a low BCS surface resistance. Its thermodynamic critical field Hc is higher than Nb, potentially leading to a higher maximum accelerating filed. The lower critical field Hc1 of MgB2 is lower than Nb, but it can be enhanced by...
Mr
Stewart Leith
(Universität Siegen)
09/10/2018, 09:25
Other superconducting materials beyond niobium
Considerable research is currently underway to utilise alternative materials to bulk Nb in SRF cavities. This is with the aim to increase their performance to that required by future accelerators. In this contribution, the results of two investigations into dc magnetron sputtered Nb thin films on Cu substrates are summarized, as well as initial results from research which has been conducted...
Mr
David Beverstock
(Jefferson Lab)
09/10/2018, 09:50
Other superconducting materials beyond niobium
Further enhancement of superconducting accelerating cavity performance calls upon the development of materials beyond bulk niobium (Nb). Superconducting RF (SRF) is a surface phenomenon; for most superconducting materials the RF penetration depth is in the range of hundreds of nanometers. Due to the field penetration enhancement occurring in films with a thickness smaller than their nominal...
Mr
Thomas Oseroff
(Cornell University)
09/10/2018, 10:15
Other superconducting materials beyond niobium
A TE mode niobium sample host cavity was used to characterize the RF performance of large 5” diameter thin film samples at 4 GHz. Exciting results were obtained from industry partner Ultramet’s CVD Nb3Sn grown on a copper substrate. These results indicate that slight alterations to the deposition process and use of higher purity precursors could lead to high-performance Nb3Sn coatings on...
Mr
Sebastian Keckert
(Helmholtz-Zentrum Berlin)
09/10/2018, 10:40
Other superconducting materials beyond niobium
RF-surface resistance measurements have been performed on an S-I-S multilayer sample.
The sample was prepared at JLab using DC-magnetron sputtering of a 75 nm NbTiN layer on a 15 nm AlN insulator layer on bulk niobium. The sample (and sputtered area) was a circular disc of 75 mm diameter, welded on an 85 mm high Nb pipe of the same outer diameter. This geometry allowed performing RF...
