Search Results - "Ciovati, G."

Effect of vortex hotspots on the radio-frequency surface resistance of superconductors by Gurevich, A., Ciovati, G.

“…We present detailed experimental and theoretical investigations of hotspots produced by trapped vortex bundles and their effect on the radio-frequency (rf)…”
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Flux expulsion in niobium superconducting radio-frequency cavities of different purity and essential contributions to the flux sensitivity by Dhakal, P., Ciovati, G., Gurevich, A.

“…Magnetic flux trapped during the cooldown of superconducting radio-frequency cavities through the transition temperature due to incomplete Meissner state is…”
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Decrease of the surface resistance in superconducting niobium resonator cavities by the microwave field by Ciovati, G., Dhakal, P., Gurevich, A.

“…Measurements of the quality factor, Q, of Nb superconducting microwave resonators often show that Q increases by ≃10%–30% with increasing radio-frequency (rf)…”
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Dynamics of vortex penetration, jumpwise instabilities, and nonlinear surface resistance of type-II superconductors in strong rf fields by Gurevich, A., Ciovati, G.

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Magneto-thermal limitations in superconducting cavities at high radio-frequency fields by Parajuli, I., Ciovati, G., Gurevich, A.

“…The performance of superconducting radio-frequency Nb cavities at high radio-frequency (rf) fields in the absence of field emission can be limited by either a…”
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Review of ingot niobium as a material for superconducting radiofrequency accelerating cavities by Kneisel, P., Ciovati, G., Dhakal, P., Saito, K., Singer, W., Singer, X., Myneni, G.R.

“…As a result of collaboration between Jefferson Lab and niobium manufacturer Companhia Brasileira de Metalurgia e Mineração (CBMM), ingot niobium was explored…”
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Effect of high temperature heat treatments on the quality factor of a large-grain superconducting radio-frequency niobium cavity by Dhakal, P., Ciovati, G., Myneni, G. R., Gray, K. E., Groll, N., Maheshwari, P., McRae, D. M., Pike, R., Proslier, T., Stevie, F., Walsh, R. P., Yang, Q., Zasadzinzki, J.

“…Large-grain Nb has become a viable alternative to fine-grain Nb for the fabrication of superconducting radio-frequency cavities. In this contribution we report…”
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High field Q slope and the effect of low-temperature baking at 3 GHz by Ciovati, G., Eremeev, G., Hannon, F.

“…A strong degradation of the unloaded quality factor with field, called high fieldQslope, is commonly observed aboveBp≅100mTin elliptical superconducting…”
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Design of a cw, low-energy, high-power superconducting linac for environmental applications by Ciovati, G., Anderson, J., Coriton, B., Guo, J., Hannon, F., Holland, L., LeSher, M., Marhauser, F., Rathke, J., Rimmer, R., Schultheiss, T., Vylet, V.

“…The treatment of flue gases from power plants and municipal or industrial wastewater using electron beam irradiation technology has been successfully…”
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High field Q slope and the baking effect: Review of recent experimental results and new data on Nb heat treatments by Ciovati, G., Myneni, G., Stevie, F., Maheshwari, P., Griffis, D.

“…Here, the performance of superconducting radio-frequency (SRF) cavities made of bulk Nb at high fields (peak surface magnetic field greater than about 90 mT)…”
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Successful user operation of a superconducting radio-frequency photoelectron gun with Mg cathodes by Teichert, J., Arnold, A., Ciovati, G., Deinert, J.-C., Evtushenko, P., Justus, M., Klopf, J. M., Kneisel, P., Kovalev, S., Kuntzsch, M., Lehnert, U., Lu, P., Ma, S., Murcek, P., Michel, P., Ryzhov, A., Schaber, J., Schneider, C., Schurig, R., Steinbrück, R., Vennekate, H., Will, I., Xiang, R.

“…At the electron linac for beams with high brilliance and low emittance (ELBE) center for high-power radiation sources, the second version of a superconducting…”
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Development of a prototype superconducting radio-frequency cavity for conduction-cooled accelerators by Ciovati, G., Anderson, J., Balachandran, S., Cheng, G., Coriton, B., Daly, E., Dhakal, P., Gurevich, A., Hannon, F., Harding, K., Holland, L., Marhauser, F., McLaughlin, K., Packard, D., Powers, T., Pudasaini, U., Rathke, J., Rimmer, R., Schultheiss, T., Vennekate, H., Vollmer, D.

“…The higher efficiency of superconducting radio-frequency (SRF) cavities compared to normal-conducting ones enables the development of high-energy…”
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Detection of surface carbon and hydrocarbons in hot spot regions of niobium superconducting rf cavities by Raman spectroscopy by Cao, C., Ford, D., Bishnoi, S., Proslier, T., Albee, B., Hommerding, E., Korczakowski, A., Cooley, L., Ciovati, G., Zasadzinski, J. F.

“…Raman microscopy/spectroscopy measurements are presented on high purity niobium (Nb) samples, including pieces from hot spot regions of a tested…”
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Mechanical properties of niobium radio-frequency cavities by Ciovati, G., Dhakal, P., Matalevich, J., Myneni, G., Schmidt, A., Iversen, J., Matheisen, A., Singer, W.

“…Radio-frequency cavities made of bulk niobium are one of the components used in modern particle accelerators. The mechanical stability is an important aspect…”
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Evidence of high-field radio-frequency hot spots due to trapped vortices in niobium cavities by Ciovati, G., Gurevich, A.

“…Superconducting radio-frequency (rf) cavities made of high-purity niobium exhibit strong anomalous rf losses starting at peak surface magnetic fields of about…”
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Compact Horizontal Cryostat Demonstration of Superconducting Radio-Frequency Cavity with Conduction Cooling by Packard, D., Holland, L., Anderson, J., McLaughlin, K., Vollmer, D., Coriton, B., Ciovati, G., Rimmer, R., Cheng, G., Harding, K., Vennekate, J., Daly, E., Pudasaini, U., Schultheiss, T., Rathke, J.

“…Electron beam irradiation has been successfully implemented in industrial processes for many years and is now under consideration for mitigation of a variety…”
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Characterization of etch pits found on a large-grain bulk niobium superconducting radio-frequency resonant cavity by Zhao, Xin, Ciovati, G., Bieler, T. R.

“…The performance of superconducting radio-frequency (SRF) resonant cavities made of bulk niobium is limited by nonlinear localized effects. Surface analysis of…”
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Determination of the magnetic field dependence of the surface resistance of superconductors from cavity tests by Delayen, J. R., Park, H., De Silva, S. U., Ciovati, G., Li, Z.

“…We present a general method to derive the magnetic field dependence of the surface resistance of superconductors from theQ-curves obtained during the cryogenic…”
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Measurement of the high-field Q drop in a high-purity large-grain niobium cavity for different oxidation processes by Ciovati, G., Kneisel, P., Gurevich, A.

“…The most challenging issue for understanding the performance of superconducting radio-frequency (rf) cavities made of high-purity (residual resistivity ratio >…”
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Evidence of Surface Paramagnetism in Niobium and Consequences for the Superconducting Cavity Surface Impedance by Proslier, T, Kharitonov, M, Pellin, M, Zasadzinski, J, Ciovati, G

“…The presence of magnetic impurities in native niobium oxides have been confirmed by Point contact spectroscopy (PCT), SQUID magnetometry and Electron…”
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