A5001473182- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Physics of Superconductivity and Magnetism
- Magnetic confinement fusion research
- Gyrotron and Vacuum Electronics Research
- Dark Matter and Cosmic Phenomena
- Superconducting and THz Device Technology
- Particle Detector Development and Performance
- Metal and Thin Film Mechanics
- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Energy Harvesting in Wireless Networks
- Spacecraft and Cryogenic Technologies
- Silicon Carbide Semiconductor Technologies
- Plasma Diagnostics and Applications
- Superconductivity in MgB2 and Alloys
- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Distributed and Parallel Computing Systems
- Mechanical and Optical Resonators
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Radio Astronomy Observations and Technology
- Fusion materials and technologies
Fermi National Accelerator Laboratory
2016-2025
Government of the United States of America
2022
Brigham Young University
2021
Cornell University
2011-2019
Illinois Institute of Technology
2016
Fermi Research Alliance
2015
Very-high-quality-factor superconducting radio-frequency cavities developed for accelerators can enable fundamental physics searches with orders of magnitude higher sensitivity, and they also offer a path to 1000-fold increase in the achievable coherence times cavity-stored quantum states three-dimensional circuit QED architecture. Here we report measurements multiple accelerator resonant frequencies ${f}_{0}=1.3$, 2.6, 5 GHz down temperatures about 10 mK field levels few photons, which...
We report the finding of new surface treatments that permit to manipulate niobium resonator nitrogen content in first few nanometers a controlled way, and fundamental Mattis-Bardeen resistance residual accordingly. In particular, we find infusion conditions systematically a) increase quality factor these 1.3 GHz superconducting radio frequency (SRF) bulk resonators, up very high gradients; b) achievable accelerating gradient cavity compared its own baseline with state-of-the-art processing....
A microns-thick film of Nb3Sn on the inner surface a superconducting radiofrequency (SRF) cavity has been demonstrated to substantially improve cryogenic efficiency compared standard niobium material, and its predicted superheating field is approximately twice as high. We review in detail advantages coatings for SRF cavities. describe vapor diffusion process used fabricate this material most successful experiments, we compare differences at different labs. overview results coatings,...
We report on an effort to improve the performance of superconducting radiofrequency cavities by using heat treatment in a temperature range sufficient dissociate natural surface oxide. find that residual resistance is decreased significantly, and we unexpected reduction Bardeen-Cooper-Schrieffer (BCS) resistance. Together these result extremely high-quality factor values at relatively large accelerating fields ${E}_{\mathrm{acc}}$ \ensuremath{\sim} 20 MV/m: ${Q}_{0}$ = 3--4...
The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in 2030s. ILC addresses key questions for our current understanding of particle physics. It based proven technology. Its experiments will challenge Standard Model physics and provide window to look beyond it. This document brings story up date, emphasizing its strong motivation, readiness construction, opportunity it presents US community.
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 -Dark SRF-and report results of its pathfinder run. Our new experimental setup enables improvements in sensitivity over previous searches and covers photon parameter space. design delicate calibration measurement protocols to utilize high-Q at Dark SRF. Using operating 1.3 GHz, we establish a exclusion limit kinetic...
Even when cooled through its transition temperature in the presence of an external magnetic field, a superconductor can expel nearly all flux. This paper presents experimental study to identify parameters that most strongly influence flux trapping high purity niobium during cooldown. is critical operation superconducting radiofrequency cavities, which trapped degrades quality factor and therefore cryogenic efficiency. Flux expulsion was measured on large survey 1.3 GHz cavities prepared...
Abstract Nb 3 Sn is a promising next-generation material for superconducting radiofrequency cavities, with significant potential both large scale and compact accelerator applications. However, so far, cavities have been limited to continuous wave accelerating fields <18 MV m −1 . In this paper, new results are presented significantly higher fields, as high 24 in single cell cavities. Results also from the first ever Sn-coated 1.3 GHz 9-cell cavity, full-scale demonstration on cavity type...
We propose a novel search technique for axions with $CP$-violating monopole coupling ${\stackrel{\texttildelow{}}{g}}_{Q}$ to bulk Standard Model charges $Q\ensuremath{\in}{B,L,B\ensuremath{-}L}$. Gradients in the static axion field configurations sourced by matter induce achromatic circular photon birefringence via axion-photon ${g}_{\ensuremath{\phi}\ensuremath{\gamma}}$. Circularly polarized light fed into an optical or (open) radio-frequency (RF) Fabry-P\'erot (FP) cavity develops phase...
The superconducting RF linac for Linac Coherent Light Source-II calls 1.3 GHz 9-cell cavities with an average intrinsic quality factor Q0 of 2.7 × 1010 at 2.0 K and 16 MV/m accelerating gradient. Two niobium 9 cell cavities, prepared nitrogen-doping Fermilab, were assembled into the Cornell Horizontal Test Cryomodule (HTC) to test cavity performance in a cryomodule that is very similar full LCLS-II cryomodule. met specifications quench field 17 3 1010. sensitivity cavities' residual...
Many future particle accelerators require hundreds of superconducting radiofrequency (SRF) cavities operating with high duty factor. The large dynamic heat load the causes cryogenic plant to make up a significant part overall cost facility. This contribution can be reduced by replacing standard niobium ones coated low-dissipation superconductor such as Nb3Sn. In this paper, we present results for single cell Nb3Sn at Cornell. Five coatings were carried out, showing that 4.2 K, Q0 out medium...
Previous work has demonstrated that the radio frequency surface resistance of niobium resonators is dramatically reduced when nitrogen impurities are dissolved as interstitial in material. This effect attributed to lowering Mattis-Bardeen with increasing accelerating field; however, microscopic origin this phenomenon poorly understood. Meanwhile, an enhancement sensitivity trapped magnetic field typically observed for such cavities. In paper, we conduct a systematic study on these different...
Theoretical limits to the performance of superconductors in high magnetic fields parallel their surfaces are key relevance current and future accelerating cavities, especially those made new higher-Tc materials such as Nb$_3$Sn, NbN, MgB$_2$. Indeed, beyond so-called superheating field $H_{\mathcal{sh}}$, flux will spontaneously penetrate even a perfect superconducting surface ruin performance. We present intuitive arguments simple estimates for combine them with our previous rigorous...
We have investigated the normal and superconducting states of technologically important compound Nb$_3$Sn using $^{93}$Nb nuclear magnetic resonance. From spin-lattice relaxation we find strong suppression zero-temperature order parameter by field. identified an anomalously large electron-nuclear exchange interaction from spin-spin measurements, magnitude beyond that dipole-dipole interaction, thereby sensitive to vortex dynamics pinning.
Superconducting radio frequency (srf) cavities, essential components of many large particle accelerators, rely on the metastable flux-free state superconducting materials. In this Letter, we present results experiments measuring magnetic field limits two srf materials, Nb and Nb_{3}Sn. Resonators made using these materials were probed both high power rf pulses dc fields. Nb, which is current standard material for cavities in applications, was found to be limited by superheating H_{sh} when...
A 1.3 GHz ${\mathrm{Nb}}_{3}\mathrm{Sn}$ superconducting radio-frequency cavity prepared with a modified annealing step reached ${B}_{pk}>50\text{ }\text{ }\mathrm{mT}$, well above ${B}_{c1}=25\ifmmode\pm\else\textpm\fi{}7\text{ without the strong $Q$-slope observed in previous cavities. At 4.2 K, it has ${Q}_{0}$ of approximately $1\ifmmode\times\else\texttimes\fi{}1{0}^{10}$ at $>10\text{ }\mathrm{MV}/\mathrm{m}$, far outperforming Nb useable gradients. 2 quench occurred...
We present an analysis of Nb3Sn surface layers grown on a bulk Niobium (Nb) coupon prepared at the same time and by vapor diffusion process used to make coatings 1.3 GHz Nb cavities. Tunneling spectroscopy reveals well-developed, homogeneous superconducting density states with gap value distribution centered around 2.7 ± 0.4 meV critical temperatures (Tc) up 16.3 K. Scanning transmission electron microscopy performed cross sections sample's region shows ∼2 μm thick layer. The elemental...
The Linac Coherent Light Source II (LCLS-II) is a new state-of-the-art coherent X-ray source being constructed at SLAC National Accelerator Laboratory. It employs 280 superconducting radio frequency (SRF) cavities in order operate continuous wave (CW) mode. To reduce the overall cryogenic cost of such large accelerator, nitrogen-doping SRF used. Nitrogen-doping has consistently been shown to increase efficiency operating 2.0 K regime and medium fields (15–20 MV/m) vertical cavity tests...
This contribution discusses the results of an in situ X-ray photoelectron spectroscopy study thermal evolution native oxide layer on Nb3Sn and pure Nb. (XPS) data were recorded with conventional spectrometers using Al Kα source for spectra collected up to 600 °C a Mg temperatures above °C. The effect thickness, composition, stability that is relevant understanding functional properties superconducting radiofrequency (SRF) cavities used particle accelerators. There consensus plays role...
We report an atomic-scale analysis of the microstructure Nb3Sn coating on Nb prepared by vapor diffusion process for superconducting radiofrequency (SRF) cavity application using transmission electron microscopy (TEM). Epitaxial growth substrate is found and four types orientation relationships at Nb3Sn/Nb interface are identified diffraction or high-resolution scanning (STEM) analysis. Thin grains observed in regions with low Sn flux they have specific relationship, (1-20)//Nb (-111)...
In this paper we present the discovery of a new surface treatment applied to superconducting radio frequency (SRF) niobium cavities, leading unprecedented accelerating fields 49 MV/m in TESLA-shaped continuous wave (CW); corresponding peak magnetic are highest ever measured CW, about 210 mT. For TESLA-shape cavities maximum quench field achieved was ~45 - reached very rarely- with most typical values being below 40 MV/m. These for surfaces treated electropolishing followed by so called mild...
Abstract We demonstrate practical accelerating gradients on a superconducting radiofrequency (SRF) accelerator cavity with cryocooler conduction cooling, cooling technique that does not involve the complexities of conventional liquid helium bath. A design is first presented enables an elliptical-cell SRF cavity. Implementing this design, single cell 650 MHz Nb 3 Sn coupled using high purity aluminum thermal links to 4 K pulse tube generated up 6.6 MV m −1 at 100% duty cycle. The experiments...