Description
B1 compounds (NbN, NbTiN...), A15 materials (Nb3Sn, V3Si, …), MgB2 and other high-Tc superconductors (oxypnictides, FeSe monolayer…), multilayer and nano-engineered structures
"As part of efforts to reduce both energy and helium consumption in future particle accelerators, such as the Future Circular Collider (FCC), investigations into alternative methodologies to bulk Nb and Nb/Cu technologies are of paramount importance. Thanks to its higher transition temperature (Tc) and lower BCS surface resistance (RBCS), Nb3Sn coated cavities should produce a quality factor...
"he development of Nb3Sn films on copper as coatings for the accelerating cavities of next generation particle accelerators is mainly driven by the sustainability goals being at the core of the I.FAST project. The successful development of a Nb3Sn/Cu scalable prototype would allow for the operation of the SRF system at 4.5 K, resulting in a reduction of the needed cryogenic power by a factor 3...
Nb3Sn has significant potential for superconducting radio-frequency (SRF) application in future particle accelerators, especially compact accelerators, which have attracted the attention of many scientific researchers. This work reports the setup and process of Nb3Sn coating at the Institute of High Energy Physics (IHEP), and presents the results of 1.3 GHz 1-cell cavities coated with Nb3Sn....
We will present on the evolution of Nb3Sn-coated accelerator cavity performance from the qualification test to the test in CEBAF cryomodule. Two Nb3Sn-coated 5-cell accelerator cavities were first measured at 4 K and 2 K in the vertical dewar test, then assembled into a CEBAF quarter cryomodule. Several precautions were taken and changes were implemented in the assembly procedures to preserve...
Copper-based Nb3Sn cavity is a promising candidate for next generation accelerator applications in the field of superconducting radio frequency (SRF). It combines the excellent thermal conductivity of copper and the superior superconducting properties of Nb3Sn, and has the potential to greatly improve the performance of the SRF cavity. The electrochemical and thermal synthesis (ETS) bronze...
Copper-based Nb3Sn cavity is a promising candidate for next generation accelerator applications in the field of superconducting radio frequency (SRF). It combines the excellent thermal conductivity of copper and the superior superconducting properties of Nb3Sn, and has the potential to greatly improve the performance of the SRF cavity. The electrochemical and thermal synthesis (ETS) bronze...
Nb3Sn has shown much promise in recent years for use in superconducting radio frequency SRF cavities. Applying and reacting a large-area thin film homogenously on the inside of a cavity requires new ingenuity in material science. We present methods to form a range of Cu-Sn composition on Cu substrates using evaporation, and we achieve Cu-Sn phases with high tin activity to facilitate...
"Nb3Sn coatings in accelerating cavities have been proposed as an alternative to drastically reduce the overall cryogenic cost in modern SRF complex accelerators. Furthermore, Nb3Sn films are among the candidates conceived to cover the interior of superconducting cavities for the search of axions (haloscopes). Thus, there is noticeable interest in assessing the superconducting properties of...
In this study we report on PVD deposition of Nb3Sn sputtered directly from an alloy target at elevated temperature about 600 °C with and without of interlayer of thick Nb layer deposited on copper substrate producing a multilayer of Cu/Nb/Nb3Sn and Cu/Nb3Sn.
The dependence of superconducting properties of the total structure on deposition parameters is been determined. The films have been...
With a higher Tc and higher critical field Hc than Nb and many Nb compounds and alloys, MgB2 is anticipated to be a promising material to be used for superconducting RF (SRF) cavities at ~20 K. We report our continuing effort towards MgB2 coated SRF cavities. MgB2 films as thick as 5 um were coated on 1.3 GHz TESLA type Cu RF cavities by hybrid physical-chemical vapor deposition (HPCVD). The...
Bulk Nb superconducting radio-frequency (SRF) cavities are widely used in accelerators, and their accelerating gradient and general performance are limited by the superheating field (Bsh). To push the theoretical limit of the Bsh, new multilayer structures are required. We fabricated Fe(Se,Te)-coated Nb films using pulsed laser deposition, performed structural characterizations, and measured...
This work describes recent developments for Nb3Sn films from sintered and stoichiometric 2-inch niobium tin targets by PVD. The final objective is to develop high quality thick Nb3Sn films (on Nb and on Cu), and SIS multilayers on SRF cavities. The effects of the target power, coating thickness, annealing temperature, and annealing time on the superconducting properties of films (RRR/Tc) were...
"For the last few decades, the material of choice for SRF cavities has been bulk niobium. RF performance of bulk $Nb$ cavity has already approached its theoretical limit. To enhance RF cavity performance and cost-efficiency, research has shifted towards the use of other alternative higher $T_c$ materials, such as $NbN$, $NbTiN$, $MgB_2$, etc. However, the use of alternative superconducting...
We introduced the New DC magnetron sputtering apparatus at KEK to create multi-layer structure on the inner surface of a superconducting radio-frequency cavity. This apparatus has the capability of coating Nb3Sn, NbN, and AlN to the elliptical 3 GHz SRF cavity as well as flat substrates up to 2-inche diameter area. The film formation using the flat sample is useful for searching the ideal...
