Related papers: Nitrogen Doping and Infusion in SRF Cavities: A Re…
Nitrogen-doping and furnace-baking are advanced high-Q0 recipes developed for 1.3 GHz TESLA-type cavities. These treatments will significantly benefit the high-Q0 linear accelerator community if they can be successfully adapted to different…
The dependence of the Q-value on the RF field (Q-slope) is actively studied in various accelerator laboratories. Although remedies against this dependence have been found, the physical cause still remains obscure. A rather straightforward…
In recent years we increased the typical maximum peak field on axis gradients obtained in L-band superconducting RF (SRF) photoinjector cavities at vertical tests to around 55 MV/m. This was achieved with niobium cathode plugs directly…
High Q-factors are of utmost importance to minimize losses of superconducting radio-frequency cavities deployed in continuous wave particle accelerators. This study elucidates the surface treatment that can maximize the Q-factors in…
Experimental data on N-doped superconducting (sc) cavities are further analyzed which contribute to confirm a recently proposed model explaining the increase of the Q-value versus the accelerating gradient.
We report on a Nb$_3$Sn-coated low-beta superconducting radio frequency (SRF) cavity intended for accelerating ions. We aim to apply the cavity in ATLAS, our Argonne National Laboratory user facility for nuclear physics studies with ion…
In this letter, we present the frequency dependence of the vortex surface resistance of bulk niobium accelerating cavities as a function of different state-of-the-art surface treatments. Higher flux surface resistance per amount of trapped…
Impurity-doping is an exciting new technology in the field of SRF, producing cavities with record-high quality factor $Q_0$ and BCS surface resistance that decreases with increasing RF field. Recent theoretical work has offered a promising…
Performance of superconducting resonators, particularly cavities for particle accelerators and micro cavities and thin film resonators for quantum computations and photon detectors has been improved substantially by recent materials…
We propose cost-effective production of medium grain (MG) niobium (Nb) discs directly sliced from forged and annealed billet. This production method provides clean surface conditions and reliable mechanical characteristics with…
Many modern and future particle accelerators employ high gradient superconducting RF (SRF) to generate beams of high energy, high intensity and high brightness for research in high energy and nuclear physics, basic energy sciences, etc. In…
Many modern and proposed future particle accelerators rely on superconducting radio frequency cavities made of bulk niobium as primary particle accelerating structures. Such cavities suffer from the anomalous field dependence of their…
It is well known that moderate temperature baking of niobium cavities can improve the surface resistance. Presently, it is believed that the diffusion of oxygen into the bulk, resulting in interstitial defects, is responsible for the…
A 218 MHz quarter wave niobium cavity has been fabricated for the purpose of demonstrating Nb3Sn technology on a low-beta accelerator cavity. Niobiumtin has been established as a promising next generation SRF material, but development has…
Ambient magnetic field, if trapped in the penetration depth, leads to the residual resistance and therefore sets the limit for the achievable quality factors in superconducting niobium resonators for particle accelerators. Here we show that…
Nb3Sn superconducting radiofrequency (SRF) cavities have substantial potential for enabling new performance capabilities for particle accelerators for high energy physics (HEP), as well as for RF cavity-based detectors for dark matter,…
A development effort to improve the performance of superconducting radio-frequency half-wave resonators (SRF HWRs) is underway at the Facility for Rare Isotope Beams (FRIB), where 220 such resonators are in operation. Our goal was to…
Point contact tunneling (PCT) spectroscopy measurements are reported over wide areas of cm-sized cut outs from niobium superconducting RF cavities. A comparison is made between a high-quality, conventionally processed (CP) cavity with a…
We present results on the effects of interstitial oxygen and carbon on a bulk-niobium superconducting radio-frequency cavity. Previous experiments have shown that high-temperature (~800 $^\circ\text{C}$) nitrogen-doping plays the dominant…
Magnetic flux expulsion properties of the superconducting material such as bulk niobium, widely used for the radio-frequency cavity fabrication, substantially affect the performance characteristics of the cavities. The quality factor of the…