Determination of the Bardeen–Cooper–Schrieffer material parameters of the HIE-ISOLDE superconducting resonator

Miyazaki, Akira; Delsolaro, W. Venturini

doi:10.1088/1361-6668/aaf049

Cited by 5 publications

(6 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This cavity has axial symmetry apart from the beam ports, and a virtually defect-free surface in the high-field region. The intrinsic quality factor Q 0 of the cavity was evaluated by standard methods [7] with a Phase Lock Loop circuit. The resonance frequency of the cavity is 101.28 MHz and the nominal power consumption is 10 W, corresponding to the surface resistance of 65 nΩ at 6 MV/m and 4.5 K.…”

Section: Methodsmentioning

confidence: 99%

Two different origins of the Q -slope problem in superconducting niobium film cavities for a heavy ion accelerator at CERN

Miyazaki

Delsolaro

2019

Phys. Rev. Accel. Beams

Self Cite

View full text Add to dashboard Cite

Superconducting niobium film cavities deposited on copper substrates (Nb/Cu) have suffered from strong field-dependent surface resistance, often referred to as the Q-slope problem, since their invention. We argue that the Q-slope may not be an intrinsic problem, but rather originates from a combination of factors which can be revealed in appropriate environmental conditions. In this study, extrinsic effects were carefully minimized in a series of experiments on a seamless cavity. The origin of the Q-slope in low frequency cavities is traced back to two contributions with different temperature and magnetic field dependences. The first component of Q-slope, affecting the residual resistance, is caused by trapped magnetic flux which is normally suppressed by a magnetic shield for bulk niobium cavities. The second, temperature dependent component of Q-slope, is similar to the medium-field Q-slope which is well known in bulk niobium cavities. These results are compared with theoretical models and possible future studies are proposed.

show abstract

Section: Methodsmentioning

confidence: 99%

Two different origins of the Q -slope problem in superconducting niobium film cavities for a heavy ion accelerator at CERN

Miyazaki

Delsolaro

2019

Phys. Rev. Accel. Beams

Self Cite

View full text Add to dashboard Cite

show abstract

“…S4 of Supplementary Information of Ref. [48]), measurements were performed only at low temperatures, T<2 K, which is about T<0.2•Tc (if we take in account, that Nb has Tc = 8.9-9.6 K [49]), and, thus, more experimental studies are required for this 4-m wide Nb/BiSbTeSe2-nanoribon/Nb junction to see the Ic(sf,T) enhancement.…”

Section: Introductionmentioning

confidence: 99%

Classifying Induced Superconductivity in Atomically Thin Dirac-Cone Materials

Talantsev

2019

Condensed Matter

View full text Add to dashboard Cite

Recently, Kayyalha et al. (Phys. Rev. Lett., 2019, 122, 047003) reported on anomalous enhancement of the self-field critical currents, Ic(sf,T), at low temperatures in Nb/BiSbTeSe2nanoribbon/Nb Josephson junctions. The enhancement was attributed to the low-energy Andreev bound states arising from winding of the electronic wave function around the circumference of the topological insulator BiSbTeSe2 nanoribbon. In this paper, we show that identical enhancement in Ic(sf,T) and in the upper critical field, Bc2(T), at approximately same reduced temperatures, were reported by several research groups in atomically thin junctions based on a variety of Dirac-cone materials (DCM) earlier. Our analysis shows that in all these S/DCM/S systems the enhancement is due to a new superconducting band opening. Taking in account that several intrinsic superconductors also exhibit the effect of new superconducting band(s) opening when sample thickness becomes thinner than the ground state out-of-plane coherence length, c(0), we strength our previous proposal that there is a new phenomenon of additional superconducting band(s) opening in atomically thin films.

show abstract

“…As the values of ξ 0 and λ L in the case of Nb on Cu coatings depend on the deposition conditions and cannot be set a priori, they also need to be included in the fitting routine. In this work, we follow the procedure described and demonstrated in [34]. Due to correlations among some of the SC parameters, different set of values could provide good agreement between data and theory.…”

Section: Rf Measurement and Analysis Methodologiesmentioning

confidence: 99%

Enhanced radio-frequency performance of niobium films on copper substrates deposited by high power impulse magnetron sputtering

Arzeo

Avino

Pfeiffer

et al. 2022

Supercond. Sci. Technol.

View full text Add to dashboard Cite

We present a study of radio frequency properties of niobium ﬁlms deposited on copper by two diﬀerent approaches based on High Power Impulse Magnetron Sputtering, namely with a DC voltage biased substrate and with bi-polar target voltage. Such approaches enable the synthesis of dense superconducting layers. The superconducting radio frequency losses of these ﬁlms are characterized as a function of the applied RF magnetic ﬁeld using a dedicated calorimetric method. We report on a signiﬁcant reduction of the Q-slope phenomenon and the residual surface resistance in the characterized ﬁlms, achieving similar values as those obtained on bulk niobium surfaces qualiﬁed with the same technique. Our results pave the way towards the realization of Nb/Cu coated accelerating cavities featuring a surface resistance 2-3 times lower than the state-of-the-art values at the working frequencies of 400 and 800 MHz, making this technology even more appealing for future particle accelerators and colliders.

show abstract

Determination of the Bardeen–Cooper–Schrieffer material parameters of the HIE-ISOLDE superconducting resonator

Cited by 5 publications

References 32 publications

Two different origins of the Q -slope problem in superconducting niobium film cavities for a heavy ion accelerator at CERN

Two different origins of the Q -slope problem in superconducting niobium film cavities for a heavy ion accelerator at CERN

Classifying Induced Superconductivity in Atomically Thin Dirac-Cone Materials

Enhanced radio-frequency performance of niobium films on copper substrates deposited by high power impulse magnetron sputtering

Contact Info

Product

Resources

About