Design and characterization of a single-channel microwave interferometer for the Helicon Physics Prototype eXperiment

Li, X.L.; Liu, Yong; Xu, G. S.; Zhou, Tianhua; Zhu, Yilun

doi:10.1016/j.fusengdes.2021.112914

Cited by 4 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the above-mentioned measurements refer to compact plasma chamber testbench at INFN-LNS (Naselli et al, 2019) and on the ion source of ATOMKI laboratory, in Debrecen (Hungary) (Biri et al, 2018) having typical size of about 30 cm in length and 10 cm in diameter, the case at hand concerns a large plasma trap-referring to the PANDORA project (Mascali et al, 2022b) which is 70 cm in length and 28 cm in diameter and it can be considered as a "bridge" case between compact traps and large size fusion plasma device also in terms of electron density n e range (~10 11 -10 13 cm −3 ). It should be mentioned that heterodyne interferometer for measuring the plasma electron density in the same range of the PANDORA case-for example in Helicon linear plasma devices -has been developed and characterized in the laboratory (Wiebold and Scharer, 2009;Li et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

Mm-wave polarimeter and profilometry design study for retrieving plasma density in the PANDORA experiment

Torrisi

Naselli²,

Donato³

et al. 2022

Front. Astron. Space Sci.

View full text Add to dashboard Cite

In the recent past, the possibility to use a superconducting trap confining a hot and dense plasma as a tool to investigate radioactivity in astrophysical scenarios has been proposed. Making possible these kind of unprecedented measurements is the main aim of the PANDORA (Plasmas for Astrophysics Nuclear Decays Observation and Radiation for Archaeometry) project. In this context, it is planned to build a compact and flexible magnetic plasma trap where plasma reaches an electron density ne ∼ 1011–1013 cm−3, and an electron temperature, in units of kT, kTe ∼ 0.1–30 keV. The setup is conceived to be able to measure, for the first time, nuclear β-decay rates in stellar-like conditions in terms of ionization states. In this paper, the design study of a mm-wave polarimeter for the PANDORA plasma line-integrated electron density measurement is presented. The paper highlights the method of this type of measurements for the first time proposed for a magneto-plasma trap which represents an “intermediate” case between the ultra-compact plasma ion sources and the large-size thermonuclear fusion devices. Preliminary measurements at scaled microwave frequencies have carried out both on a “free-space” setup by using a wire-grid polarizer and a rotable Ka-band OMT + horn antennas system, and on a compact trap (called Flexible Plasma Trap) installed at INFN-LNS and used as PANDORA down-sized testbench are described. The polarimeter technique will support β-decay investigation by simultaneous measurements of the total plasma density, which is crucial to carefully evaluate the decay-constant and to extrapolate the laboratory observed data to the astrophysical scenarios. Moreover, this work proposes to adopt an electromagnetic inverse-scattering-based technique-based method to retrieve the electron density profile along the probing antennas line-of-sight. Numerical results of this so-called “inverse profilometry” are also shown.

show abstract

Section: Introductionmentioning

confidence: 99%

Mm-wave polarimeter and profilometry design study for retrieving plasma density in the PANDORA experiment

Torrisi

Naselli²,

Donato³

et al. 2022

Front. Astron. Space Sci.

View full text Add to dashboard Cite

show abstract

Development of ultra-short pulse reflectometry on the Experimental Advanced Superconducting Tokamak (EAST)

Li,

Chen,

et al. 2024

Review of Scientific Instruments

View full text Add to dashboard Cite

Microwave reflectometry is an invaluable diagnostic tool for measuring electron density profiles in large fusion devices. Density fluctuations near the plasma cutoff layer, particularly those that are time-varying on the timescale of the reflectometry measurement, can result in distortions in phase and/or amplitude of the reflected waveform, which present challenges to the accuracy of the reconstructed profile. The ultra-short pulse reflectometry (USPR) technique eliminates the time-varying issue in that reflectometry data are collected on a nanosecond timescale, essentially freezing the fluctuations in place. An X-mode dedicated 32-channel USPR system has been developed and installed on the EAST, covering the operation frequency range from 52 to 92 GHz. This system enables high-resolution density profile measurements in the plasma pedestal and scrape-off layer, with resolutions reaching 5 mm and 1 μs, respectively. Laboratory testing of the system performance has been conducted, demonstrating the potential of the USPR technique to provide accurate and high-temporal-resolution density profiles in challenging plasma environments.

show abstract

GaN-based W-band receiver chip development for fusion plasma diagnostics

Li,

Chen,

Chen

et al. 2024

J. Inst.

View full text Add to dashboard Cite

Millimeter-wave diagnostics have proven effective on various magnetic fusion devices worldwide, yet the formidable challenges posed by the harsh environments of future burning plasma devices, characterized by extreme temperatures, pressures, and radiation levels, remain a significant hurdle. To address these challenges, the utilization of wide bandgap Gallium Nitride (GaN)-based millimeter-wave diagnostics is a most promising solution for fusion reactor safety monitoring and control. A noteworthy W-band GaN-based system-on-chip receiver has been the demonstrated by employing HRL T3 40 nm GaN technology. This receiver chip, compactly designed with dimensions of 3 × 5 mm2, incorporates essential components such as the 75–110 GHz RF Low-Noise Amplifier (LNA), mixer, Intermediate Frequency (IF) amplifier, and Local Oscillator (LO) chain. This receiver chip will be packaged as a millimeter-wave receiver module and applied on the DIII-D National Fusion Facility, for fusion plasma edge shape monitoring for operational safety and dangerous disruption prediction. The laboratory measurement results have demonstrated suitable performance. This advancement is pivotal for accurate analysis of plasma behavior in the extreme conditions of burning plasma devices, driving progress in fusion research and technology.

show abstract

Design and characterization of a single-channel microwave interferometer for the Helicon Physics Prototype eXperiment

Cited by 4 publications

References 15 publications

Mm-wave polarimeter and profilometry design study for retrieving plasma density in the PANDORA experiment

Mm-wave polarimeter and profilometry design study for retrieving plasma density in the PANDORA experiment

Development of ultra-short pulse reflectometry on the Experimental Advanced Superconducting Tokamak (EAST)

GaN-based W-band receiver chip development for fusion plasma diagnostics

Contact Info

Product

Resources

About