Cryogenic Properties of Inorganic Insulation Materials for ITER Magnets: A Review

Simon, N.J.

doi:10.2172/761710

Cited by 21 publications

(11 citation statements)

References 88 publications

(156 reference statements)

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“…Quartz also has a reasonably high thermal conductivity (4:0 W m À1 K À1 at 1 K) for an insulating substrate at low temperatures. 31,32 After patterning the NiCr elements via photolithography and wet etching, a 1 lm thick film of patterned Ag was deposited by electron beam evaporation. This Ag layer was used to connect the resistive elements to one another in the T-pad configuration, to conduct heat out of the dissipative nichrome regions, and to provide cooling of the electrons via an electron-phonon coupling.…”

Section: B Materials Selectionmentioning

confidence: 99%

Microwave attenuators for use with quantum devices below 100 mK

Wang

LeFebvre

Premaratne

et al. 2017

Journal of Applied Physics

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To reduce the level of thermally generated electrical noise transmitted to superconducting quantum devices operating at 20 mK, we have developed thin-film microwave power attenuators operating from 1 to 10 GHz. The 20 and 30 dB attenuators are built on a quartz substrate and use 75 nm thick films of nichrome for dissipative components and 1 lm thick silver films as hot electron heat sinks. The noise temperature of the attenuators was quantified by connecting the output to a 3D cavity containing a transmon qubit and extracting the dephasing rate of the qubit as a function of temperature and dissipated power P d in the attenuator. The minimum noise temperature T n of the output from the 20 dB attenuator was T n 53 mK for no additional applied power and T n % 120 mK when dissipating 30 nW. In the limit of large dissipated power (P d > 1 nW), we find T n / P 1=5:4 d , consistent with detailed thermal modeling of heat flow in the attenuators. Published by AIP Publishing.

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Section: B Materials Selectionmentioning

confidence: 99%

Microwave attenuators for use with quantum devices below 100 mK

Wang

LeFebvre

Premaratne

et al. 2017

Journal of Applied Physics

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“…The CBT sensor was installed onto the same carrier as the SEP, whereas the CeO x sensor was installed onto a G-10based PCB whose thermal conductivity is known to be lower than that of the alumina-based QHR carrier (for the CeO x carrier we could not use the same one as the QHR because the QHR and its carrier is preserved for a quantum Hall resistance standard). According to the literature, the thermal conductivities of alumina and G-10 are 0.1 Wm −1 K −1 [7] and 0.02 Wm −1 K −1 [8] at T ∼ 1 K, respectively. Thus, the actual thermal conductance of the QHR device could be better than that of the CeO x sensor at temperatures lower than 1 K.…”

Section: Thermometrymentioning

confidence: 99%

Thermal and Electrical Performance Study of Cold-Finger ³He Cryostat in Precision Measurement of Quantum Hall Resistance and Single-Electron Current

Ghee

Kim

Chae

et al. 2021

IEEE Trans. Instrum. Meas.

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“…To meet the first criterium, the trap consists of alumina (sintered Al 2 O 3 ), with adequate thermal conductivity at both room and cryogenic temperatures of 30 and 0.3 W/(m • K) [41], respectively, and a low RF loss tangent of 2 • 10 −4 [42]. Our geometry is inspired by a segmented blade design [43], however, the end caps are removed from the axis [44,45,46].…”

Section: The Ion Trapmentioning

confidence: 99%

A cryogenic radio-frequency ion trap for quantum logic spectroscopy of highly charged ions

Leopold

King

Micke

et al. 2019

Review of Scientific Instruments

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A cryogenic radio-frequency ion trap system designed for quantum logic spectroscopy of highly charged ions is presented. It includes a segmented linear Paul trap, an in-vacuum imaging lens and a helical resonator. We demonstrate ground state cooling of all three modes of motion of a single 9 Be + ion and determine their heating rates as well as excess axial micromotion. The trap shows one of the lowest levels of electric field noise published to date. We investigate the magnetic-field noise suppression in cryogenic shields made from segmented copper, the resulting magnetic field stability at the ion position and the resulting coherence time. Using this trap in conjunction with an electron beam ion trap and a deceleration beamline, we have been able to trap single highly charged Ar 13+ (Ar XIV) ions concurrently with single Be + ions, a key prerequisite for the first quantum logic spectroscopy of a highly charged ion.

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Cryogenic Properties of Inorganic Insulation Materials for ITER Magnets: A Review

Cited by 21 publications

References 88 publications

Microwave attenuators for use with quantum devices below 100 mK

Microwave attenuators for use with quantum devices below 100 mK

Thermal and Electrical Performance Study of Cold-Finger ³He Cryostat in Precision Measurement of Quantum Hall Resistance and Single-Electron Current

A cryogenic radio-frequency ion trap for quantum logic spectroscopy of highly charged ions

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