A5060982101- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Gyrotron and Vacuum Electronics Research
- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Dark Matter and Cosmic Phenomena
- Plasma Diagnostics and Applications
- Physics of Superconductivity and Magnetism
- Cold Atom Physics and Bose-Einstein Condensates
- Superconducting and THz Device Technology
- Atomic and Subatomic Physics Research
- Energy Harvesting in Wireless Networks
- Radio Frequency Integrated Circuit Design
- Particle Detector Development and Performance
- Quantum Information and Cryptography
- Particle physics theoretical and experimental studies
- Acoustic Wave Resonator Technologies
- Microwave Engineering and Waveguides
- Cosmology and Gravitation Theories
- Advanced Data Storage Technologies
- Ammonia Synthesis and Nitrogen Reduction
- Photonic and Optical Devices
- Radio Astronomy Observations and Technology
- Radiation Detection and Scintillator Technologies
- Atomic and Molecular Physics
Fermi National Accelerator Laboratory
2015-2024
Lviv Polytechnic National University
2024
European Organization for Nuclear Research
2023
Illinois Institute of Technology
2016-2021
State Space Agency of Ukraine
2017
National Academy of Sciences of Ukraine
2017
Space Research Institute
2017
Dynamic Systems (United States)
2017
Systems Control (United States)
2017
Engineering (Italy)
2017
We report a surface treatment that systematically improves the quality factor of niobium radio frequency cavities beyond expected limit for niobium. A combination annealing in partial pressure nitrogen or argon gas and subsequent electropolishing cavity leads to unprecedented low values microwave resistance, an improvement efficiency accelerating structures up 3, reducing cryogenic load superconducting both pulsed continuous duty cycles. The field dependence resistance is reversed compared...
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....
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...
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...
We report a strong effect of the cooling dynamics through $T_\mathrm{c}$ on amount trapped external magnetic flux in superconducting niobium cavities. The is similar for fine grain and single crystal all surface treatments including electropolishing with without 120$^\circ$C baking nitrogen doping. Direct field measurements cavity walls show that stems from changes trapping efficiency: slow leads to almost complete higher residual resistance while fast much more efficient expulsion lower resistance.
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...
Ambient magnetic field, if trapped in the penetration depth, leads to residual resistance and therefore sets limit for achievable quality factors superconducting niobium resonators particle accelerators. Here, we show that a complete expulsion of flux can be performed to: (1) record Q &gt; 2 × 1011 up accelerating gradient 22 MV/m; (2) ∼ 3 1010 at K 16 MV/m 190 mG fields. This is achieved by large thermal gradients normal/superconducting phase front during cooldown. Our findings open way...
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...
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...
In this paper, we discuss error analysis for intrinsic quality factor (Q0) and accelerating gradient (Eacc) measurements in superconducting radio frequency (SRF) resonators. The is applicable cavity performance tests that are routinely performed at SRF facilities worldwide. We review the sources of uncertainties along with assumptions on their correlations present uncertainty calculations a more complete procedure treatment than previous publications [T. Powers, Proceedings 12th Workshop RF...
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...
This is a Snowmass white paper on the utility of existing and future superconducting cavities to probe fundamental physics. Superconducting radio frequency (SRF) cavity technology has seen tremendous progress in past decades, as tool for accelerator science. With advances spear-headed by SQMS center at Fermilab, they are now being brought quantum regime becoming science thanks high degree coherence. The same quality factor can be leveraged search new physics, including searches particles,...
Previous studies on magnetic flux expulsion as a function of cooldown procedures for elliptical superconducting radio frequency (SRF) niobium cavities showed that when the cavity beam axis is placed parallel to helium cooling flow and sufficiently large thermal gradients are achieved, all could be expelled very low residual resistance achieved. In this paper, we investigate trapping case resonators positioned perpendicularly flow, which more representative how SRF cooled in accelerators...
The discovery of nitrogen-doping treatment revealed that the radio frequency surface resistance niobium resonators may be significantly reduced when nitrogen impurities are dissolved as interstitials in material. A peculiar behavior exhibited by N-doped cavities is anti-Q slope, i.e., a reduction temperature-dependent component function accelerating field. This unusual trend has been attributed to presence interstitial lattice after doping treatment. Letter presents focused study on field...
Cryogenic superconducting niobium resonators are key to accelerators for free-electron lasers and experiments in particle nuclear physics. A resonator's performance is often degraded by a magnetic field that trapped it during quench event. Without clear understanding of this field's origin, the problem has been addressed thermal cycling above cavity's critical temperature. Now authors pinpoint mechanism responsible flux, show how fully recover quality factor while staying...
When a superconducting radiofrequency cavity is cooled through its critical temperature, ambient magnetic flux can become ``frozen in'' to the superconductor, resulting in degradation of quality factor. This especially problematic applications where factor cost driver, such as cw linac for LCLS-II. Previously, it had been unknown how prevent from being trapped during cooldown bulk niobium cavities, but recent R studies showed near-full expulsion be achieved high temperature heat treatment...
In dark-matter searches using axion haloscopes, the search sensitivity depends on quality factors (${Q}_{0}$) of radio-frequency cavities immersed in multitesla magnetic fields. Increasing ${Q}_{0}$ would increase scan rate through parameter space interest. Researchers developing superconducting for particle accelerators have developed methods obtaining extremely high approximately ${10}^{11}$ microteslascale this paper, we describe efforts to develop high-$Q$ made from...
High Q-factors are of utmost importance to minimize losses superconducting radio-frequency cavities deployed in continuous wave particle accelerators. This study elucidates the surface treatment that can maximize high-beta 650 MHz elliptical niobium cavities. State-of-the-art treatments applied many single-cell cavities, and resistance studies performed understand microwave dissipation at this unexplored frequency. The nitrogen doping is confirmed be necessary medium RF fields. We five-cell...
Wavelike, bosonic dark matter candidates like axions and photons can be detected using microwave cavities known as haloscopes. Traditionally, haloscopes consist of tunable copper operating in the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi>TM</a:mi></a:mrow><a:mrow><a:mn>010</a:mn></a:mrow></a:msub></a:mrow></a:math> mode, but ohmic losses have limited their performance. In contrast, superconducting radio frequency (SRF) achieve quality...
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 report results of its pathfinder run. Our new experimental setup enables improvements in sensitivity over previous searches covers photon parameter space. design delicate calibration measurement protocols to utilize high-$Q$ at Dark SRF. Using operating $1.3 \ \text{GHz}$, we establish a exclusion limit kinetic...
Wavelike, bosonic dark matter candidates like axions and photons can be detected using microwave cavities commonly referred to as haloscopes. Traditionally, haloscopes consist of tunable copper operating in the TM$_{010}$ mode, but ohmic losses have limited their performance. In contrast, superconducting radio frequency (SRF) achieve quality factors $\sim 10^{10}$, perhaps five orders magnitude better than cavities, which would lead more sensitive detectors. this paper, we first derive that...