2 research outputs found
Development of thin films for superconducting RF cavities
Superconducting coatings for superconducting radio frequency (SRF) cavities is an intensively developing field that should ultimately lead to acceleration gradients better than those obtained by bulk Nb RF cavities. ASTeC has built and developed experimental systems for superconducting thin-film deposition, surface analysis and measurement of Residual Resistivity Ratio (RRR). Nb thin-films were deposited by magnetron sputtering in DC or pulsed DC mode (100 to 350 kHz with 50% duty cycle) with powers ranging from 100 to 600 W at various temperatures ranging from room temperature to 800 °C on Si (100) substrates. The first results gave RRR in the range from 2 to 22 with a critical temperature Tc ≈ 9.5 K. Scanning electron microscopy (SEM), x-ray diffraction (XRD), electron back scattering diffraction (EBSD) and DC SQUID magnetometry revealed significant correlations between the film structure, morphology and superconducting properties
Physical vapour deposition of thin films for use in superconducting RF cavities
The production of superconducting coatings for radio
frequency cavities is a rapidly developing field that
should ultimately lead to acceleration gradients greater
than those obtained by bulk Nb RF cavities. Optimizing
superconducting properties of Nb thin-films is therefore
essential. Nb films were deposited by magnetron
sputtering in pulsed DC mode onto Si (100) and MgO
(100) substrates and also by high impulse magnetron
sputtering (HiPIMS) onto Si (100), MgO (100) and
polycrystalline Cu. The films were characterised using
scanning electron microscopy, x-ray diffraction and DC
SQUID magnetometry