Publications (50)
Quantifying Trapped Magnetic Vortex Losses in Niobium Resonators at mK Temperatures
D. Bafia, B. Abdisatarov, R. Pilipenko +4
Trapped magnetic vortices in niobium introduce microwave losses that degrade the performance of superconducting resonators. While such losses have been extensively studied above 1~…
Three-dimensional superconducting resonators at mK with the photon lifetime up to seconds
A. Romanenko, R. Pilipenko, S. Zorzetti +5
Very high quality factor superconducting radio frequency cavities developed for accelerators can enable fundamental physics searches with orders of magnitude higher sensitivity, as…
Strong Meissner screening change in superconducting radio frequency cavities due to mild baking
A. Romanenko, A. Grassellino, F. Barkov +3
We investigate "hot" regions with anomalous high field dissipation in bulk niobium superconducting radio frequency cavities for particle accelerators by using low energy muon spin…
Quantum mechanics on Riemannian Manifold in Schwinger's Quantization approach III
N. Chepilko, A. Romanenko
Using extended Schwinger's quantization approach quantum mechanics on a Riemannian manifold with a given action of an intransitive group of isometries is developed. It was show…
Direct Measurement of Microwave Loss in Nb Films for Superconducting Qubits
B. Abdisatarov, D. Bafia, A. Murthy +9
Niobium films are a key component in modern two-dimensional superconducting qubits, yet their contribution to the total qubit decay rate is not fully understood. The presence of di…
Future Circular Collider Feasibility Study Report: Volume 1, Physics, Experiments, Detectors
M. Benedikt, F. Zimmermann, B. Auchmann +1461
Volume 1 of the FCC Feasibility Report presents an overview of the physics case, experimental programme, and detector concepts for the Future Circular Collider (FCC). This volume o…
Quantum mechanics on Riemannian Manifold in Schwinger's Quantization Approach II
N. Chepilko, A. Romanenko
Extended Schwinger's quantization procedure is used for constructing quantum mechanics on a manifold with a group structure. The considered manifold is a homogeneous Riemannian…
HELEN: A Linear Collider Based On Advanced SRF Technology
S. Belomestnykh, P. C. Bhat, M. Checchin +9
This paper discusses recently proposed Higgs Energy LEptoN (HELEN) linear collider based on advances in superconducting radio frequency technology. The collider offers cost…
Advancement in the understanding of the field and frequency dependent microwave surface resistance of niobium
M. Martinello, S. Aderhold, S. K. Chandrasekaran +6
The radio-frequency surface resistance of niobium resonators is incredibly reduced when nitrogen impurities are dissolved as interstitial in the material, conferring ultra-high Q-f…
Efficient expulsion of magnetic flux in superconducting RF cavities for high applications
S. Posen, A. Grassellino, A. Romanenko +5
Even when cooled through its transition temperature in the presence of an external magnetic field, a superconductor can expel nearly all external magnetic flux. This Letter present…
Effect of interstitial impurities on the field dependent microwave surface resistance of niobium
M. Martinello, A. Grassellino, M. Checchin +5
Previous work has demonstrated that the radio frequency surface resistance of niobium resonators is dramatically reduced when nitrogen impurities are dissolved as interstitial in t…
Performance-defining properties of NbSn coating in SRF cavities
Y. Trenikhina, S. Posen, A. Romanenko +4
NbSn has great potential to become the material of choice for fabrication of SRF cavities. The higher critical temperature of NbSn potentially allows for an increased opera…
Dependence of the residual surface resistance of superconducting RF cavities on the cooling dynamics around
A. Romanenko, A. Grassellino, O. Melnychuk +1
We report a strong effect of the cooling dynamics through on the amount of trapped external magnetic flux in superconducting niobium cavities. The effect is similar…
Understanding the Mechanism of the Performance Improvement in Nitrogen-doped Niobium Superconducting Radio Frequency Cavity
Xiaotian Fang, Jin-Su Oh, Matt Kramer +4
Niobium superconducting radiofrequency cavities enable applications in modern accelerators and quantum computers. However, the surface resistance significantly deteriorates the cav…
Quantum mechanics on Riemannian Manifold in Schwinger's Quantization Approach I
N. Chepilko, A. Romanenko
Schwinger's quantization scheme is extended in order to solve the problem of the formulation of quantum mechanics on a space with a group structure. The importance of Killing vecto…
Optimizing Superconducting Nb Film Cavities by Mitigating Medium-Field Q-Slope Through Annealing
B. Abdisatarov, G. Eremeev, H. E. Elsayed-Ali +9
Niobium films are of interest in applications in various superconducting devices, such as superconducting radiofrequency cavities for particle accelerators and superconducting qubi…
Disentangling the sources of ionizing radiation in superconducting qubits
L. Cardani, I. Colantoni, A. Cruciani +27
Radioactivity was recently discovered as a source of decoherence and correlated errors for the real-world implementation of superconducting quantum processors. In this work, we mea…
New Exclusion Limit for Dark Photons from an SRF Cavity-Based Search (Dark SRF)
A. Romanenko, R. Harnik, A. Grassellino +11
We conduct the first ``light-shining-through-wall" (LSW) search for dark photons using two state-of-the-art high quality-factor superconducting radio frequency (SRF) cavities and r…
Achievement of Ultra-High Quality Factor in Prototype Cryomodule for LCLS-II
G. Wu, A. Grassellino, E. Harms +4
Quality factor is a primary cost driver for high energy, continuous wave (CW) SRF linacs like the LCLS-II X-ray free electron laser currently under construction. Taking this into a…
Magnetic Fluctuations in Niobium Pentoxide
Y. Krasnikova, A. A. Murthy, F. Crisa +10
Using a spin-polarized muon beam we were able to capture magnetic dynamics in an amorphous niobium pentoxide thin film. Muons are used to probe internal magnetic fields produced by…
Key directions for research and development of superconducting radio frequency cavities
S. Belomestnykh, S. Posen, D. Bafia +53
Radio frequency superconductivity is a cornerstone technology for many future HEP particle accelerators and experiments from colliders to proton drivers for neutrino facilities to…
Nitrogen and argon doping of niobium for superconducting radio frequency cavities: a pathway to highly efficient accelerating structures
A. Grassellino, A. Romanenko, O. Melnychuk +7
We report a surface treatment that systematically improves the quality factor of niobium radio frequency cavities beyond the expected limit for niobium. A combination of annealing…
Cooling Dynamics Through Transition Temperature of Niobium SRF Cavities Captured by Temperature Mapping
M. Martinello, A. Romanenko, M. Checchin +4
Cool-down dynamics of superconducting accelerating cavities became particularly important for obtaining very high quality factors in SRF cavities. Previous studies proved that when…
Advances in Nb3Sn superconducting radiofrequency cavities towards first practical accelerator applications
S. Posen, J. Lee, D. N. Seidman +4
Nb3Sn is a promising next-generation material for superconducting radiofrequency cavities, with significant potential for both large scale and compact accelerator applications. How…
Nanostructural features degrading the performance of superconducting radio frequency niobium cavities revealed by TEM and EELS
Y. Trenikhina, A. Romanenko, J. Kwon +2
Nanoscale defect structure within the magnetic penetration depth of ~100nm is key to the performance limitations of niobium superconducting radio frequency (SRF) cavities. Using a…
Proximity breakdown of hydrides in superconducting niobium cavities
A. Romanenko, F. Barkov, L. D. Cooley +1
Many modern and proposed future particle accelerators rely on superconducting radio frequency cavities made of bulk niobium as primary particle accelerating structures. Such caviti…
Understanding Quality Factor Degradation in Superconducting Niobium Cavities at Low Microwave Field Amplitudes
A. Romanenko, D. I. Schuster
In niobium superconducting radio frequency (SRF) accelerating cavities a decrease of the quality factor at lower fields - a so called \emph{low field Q slope or LFQS} - has been a…
Signatures of Enhanced Superconducting Properties in Niobium Cavities
D. Bafia, A. Grassellino, M. Checchin +2
Superconducting radio-frequency (SRF) niobium cavities are critical for modern particle accelerators, as well as for advancing superconducting quantum systems and enabling ultra-se…
The Effect of Mechanical Cold Work on the Magnetic Flux Expulsion of Niobium
S. Posen, S. K. Chandrasekaran, A. C. Crawford +5
Expulsion of ambient flux has been shown to be crucial to obtain high quality factors in bulk niobium SRF cavities. However, there remain many questions as to what properties of th…
Unprecedented Quality Factors at Accelerating Gradients up to 45 MV/m in Niobium Superconducting Resonators via Low Temperature Nitrogen Infusion
A. Grassellino, A. Romanenko, Y. Trenikhina +9
We report the finding of new surface treatments that permit to manipulate the niobium resonator nitrogen content in the first few nanometers in a controlled way, and the resonator…
Future Circular Collider Feasibility Study Report: Volume 3, Civil Engineering, Implementation and Sustainability
M. Benedikt, F. Zimmermann, B. Auchmann +1461
Volume 3 of the FCC Feasibility Report presents studies related to civil engineering, the development of a project implementation scenario, and environmental and sustainability asp…
Magnetic Flux Dynamics in Horizontally Cooled Superconducting Cavities
M. Martinello, M. Checchin, A. Grassellino +4
Previous studies on magnetic flux expulsion as a function of cooling details have been performed for superconducting niobium cavities with the cavity beam axis placed parallel resp…
Insight into bulk niobium superconducting RF cavities performances by tunneling spectroscopy
N. R. Groll, G. Ciovati, A. Grassellino +3
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 h…
Project X: Broader Impacts
D. M. Asner, P. C. Bhat, S. Henderson +9
Part-3 of "Project X: Accelerator Reference Design, Physics Opportunities, Broader Impacts". The proposed Project X proton accelerator at Fermilab, with multi-MW beam power and hig…
Comment on the "Decrease of the surface resistance in superconducting niobium resonator cavities by the microwave field"
A. Romanenko, A. Grassellino
In a recent publication [Appl. Phys. Lett. 104, 092601 (2014)] Ciovati et al. claim that: 1) thermal effects were disregarded in our original work [*]; 2) increase of at …
Quench-Induced Degradation of the Quality Factor in Superconducting Resonators
M. Checchin, M. Martinello, A. Romanenko +5
Quench of superconducting radio-frequency cavities frequently leads to the lowered quality factor Q0, which had been attributed to the additional trapped magnetic flux. Here we dem…
Fermilab experience of post-annealing losses in SRF niobium cavities due to furnace contamination and the ways to its mitigation: a pathway to processing simplification and quality factor improvement
A. Grassellino, A. Romanenko, A. Crawford +10
We investigate the effect of high temperature treatments followed by only high-pressure water rinse (HPR) of superconducting radio frequency (SRF) niobium cavities. The objective i…
Accelerator physics and technology research toward future multi-MW proton accelerators
V. Shiltsev, P. Hurh, A. Romanenko +2
Recent P5 report indicated the accelerator-based neutrino and rare decay physics research as a centrepiece of the US domestic HEP program. Operation, upgrade and development of the…
Future Circular Collider Feasibility Study Report: Volume 2, Accelerators, Technical Infrastructure and Safety
M. Benedikt, F. Zimmermann, B. Auchmann +1461
In response to the 2020 Update of the European Strategy for Particle Physics, the Future Circular Collider (FCC) Feasibility Study was launched as an international collaboration ho…
Accelerating fields up to 49 MV/m in TESLA-shape superconducting RF niobium cavities via 75C vacuum bake
A. Grassellino, A. Romanenko, D. Bice +9
In this paper we present the discovery of a new surface treatment applied to superconducting radio frequency (SRF) niobium cavities, leading to unprecedented accelerating fields of…
High quality superconducting Nb co-planar resonators on sapphire substrate
S. Zhu, F. Crisa, M. Bal +10
We present measurements and simulations of superconducting Nb co-planar waveguide resonators on sapphire substrate down to millikelvin temperature range with different readout powe…
Multi-modal electron microscopy study on decoherence sources and their stability in Nb based superconducting qubit
Jin-Su Oh, Xiaotian Fang, Tae-Hoon Kim +14
Niobium is commonly used for superconducting quantum systems as readout resonators, capacitors, and interconnects. The coherence time of the superconducting qubits is mainly limite…
Plasma Processing for In-Situ Field Emission Mitigation of Superconducting Radiofrequency (SRF) Cryomodules
M. Martinello, P. Berrutti, B. Giaccone +14
Field emission (FE) is one of the main limiting factors of superconducting radio-frequency (SRF) cavities operating in accelerators and it occurs whenever contaminants, like dust,…
Higgs-Energy LEptoN (HELEN) Collider based on advanced superconducting radio frequency technology
S. Belomestnykh, P. C. Bhat, A. Grassellino +15
This Snowmass 2021 contributed paper discusses a Higgs-Energy LEptoN (HELEN) linear collider based on advances superconducting radio frequency technology. The proposed col…
Ultra-Low Surface Resistance via Vacuum Heat Treatment of Superconducting Radiofrequency Cavities
S. Posen, A. Romanenko, A. Grassellino +2
We report on an effort to improve the performance of superconducting radiofrequency cavities by the use of heat treatment in a temperature range sufficient to dissociate the natura…
Ultra-high quality factors in superconducting niobium cavities in ambient magnetic fields up to 190 mG
A. Romanenko, A. Grassellino, A. C. Crawford +2
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 nio…
Dependence of the microwave surface resistance of superconducting niobium on the magnitude of the rf field
A. Romanenko, A. Grassellino
Utilizing difference in temperature dependencies we decoupled BCS and residual components of the microwave surface resistance of superconducting niobium at all rf fields up to $B_\…
Experimental Observation of Short-Range Magnetic Correlations in Amorphous NbO and TaO Thin Films
Y. V. Krasnikova, A. A. Murthy, D. Bafia +17
We use muon spin rotation/relaxation/resonance (SR) to investigate the magnetic properties of niobium pentoxide (NbO) and tantalum pentoxide (TaO) thin films. I…
Some wakefield effects in the superconducting RF cavities of LCLS-II
K. Bane, A. Romanenko, V. Yakovlev
For LCLS-II we estimate the power of radiated wakefields generated in the SRF cavities (including the 3rd harmonic cavities) and in the end transitions. Much of this power will pas…
HELEN: Traveling Wave SRF Linear Collider Higgs Factory
S. Belomestnykh, P. C. Bhat, A. Grassellino +7
Traveling wave SRF accelerating structures offer several advantages over the traditional standing wave structures: substantially lower and lower , ratios o…