Conveners
Nb thin film technology
- Teng Tan (Institute of Modern Physics, Chinese Academy of Science)
Nb thin film technology: Discussion
- Guillaume Rosaz (CERN)
At LNL the R&D on Niobium on Copper cavities coating film technology is of great importance since the development of Quarter Wave Resonators of the ALPI accelerator. The 6 GHz elliptical cavities represent a low-cost research that is a key step to go through from the prototypes into the real cavities in the framework of the accelerator technology. Thick films deposited in long pulse DCMS...
Coating low beta accelerating structures has been shown [1,2,3] to be challenging, first because the standard coating technique that is Direct Current Magnetron Sputtering leads to more porous layers as the cavities’ beta factor decreases. A second issue is the non-uniform thickness distribution resulting in a film that can be six times thicker at the iris than at the equator. This can lead to...
Especially in neutral-dominant, low-power DCMS discharges, sputtering is treated often implicitly as a line-of-sight process: The relative growth-rate of a film at a given location is dominated by the position and orientation with respect to the closest sputtering surface. However, complications can arise due to the complex geometry of a substrate, particularly with multiple sputtering...
Retarding Field Analyzer (RFA) and Langmuir probe measurements were carried out in a $3$ inch magnetron system with a niobium target operating in argon to determine how positive polarity pulses in the HiPIMS voltage waveform can change the dynamics of the plasma and influence thin film properties.
The positive voltage pulses were introduced in the early afterglow with heights $U_{pos}$...
Nb on Cu structure was proposed instead of the bulk Nd for SRF applications because it is chipper and possesses better thermal properties. For such structure is very important to have good mechanical, electrical, and magnetic properties. An adhesion of Nb on Cu substrate depends on both Nb and Cu crystallinity and Nb deposition technology and thickness of Nb film. The DC entry field Hen and...
