Review of Scientific Instruments最新文献

{"title":"Collective Thomson scattering electronics for a burning plasma device.","authors":"Pengjun Sun, Haiqing Liu, Calvin Domier, Xinhang Xu, Hsiangying Lai, Logan Himes, Jon Dannenberg, Baron Li, Khadija Rahman, Xiaoliang Li, Jacob Farias-Hesson, Yilun Zhu","doi":"10.1063/5.0349935","DOIUrl":"https://doi.org/10.1063/5.0349935","url":null,"abstract":"<p><p>A collective Thomson scattering (CTS) diagnostic is under development to measure the density and energy spectrum of alpha particles in a burning plasma device. The scattering source is a 1 MW, 105 GHz gyrotron, chosen to avoid both absorption and cutoff within the burning plasma. Scattered signals are collected by seven front-end receivers spanning 100-110 GHz, each positioned at a different scattering angle. A 105 GHz notch filter with >60 dB depth protects the receivers from unscattered power, while a WR-10 bandpass filter rejects 170 GHz electron cyclotron heating signals. A 96 GHz high-pass filter enables single-sideband operation, and image rejection filters allow downconversion using a 100 GHz local oscillator to an intermediate frequency range of 2-12 GHz. The seven front-end receiver modules provide >30 dB conversion gain. The back-end electronics comprise 28 radiometer modules that generate 448 frequency channels, with high-resolution (100 MHz spacing) and low-resolution (190 MHz spacing) configurations optimized for bulk ion and fast-ion measurements, respectively. Detailed sensitivity analysis, accounting for system losses, receiver noise, and expected plasma emission, predicts a signal-to-noise ratio of >10 for the bulk ion feature and >5 for the fast-ion tails under nominal operating conditions, demonstrating the diagnostic's viability. The CTS diagnostic is predicted to achieve a spatial resolution of ∼5 cm and a time resolution of 80 ms, sufficient to resolve alpha-particle slowing-down dynamics.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thomson scattering in high-background plasmas using polarization-resolved spectroscopy.","authors":"J Katz, R Boni, D Nelson, J Rosenbluth, G F Swadling, S T Ivancic","doi":"10.1063/5.0352344","DOIUrl":"https://doi.org/10.1063/5.0352344","url":null,"abstract":"<p><p>Diagnosing the conditions of high-energy-density plasmas using optical Thomson scattering is often hindered by strong background signals present in the data. Separating scattered light by the polarization state allows discrimination between the Thomson-scattered signal and the thermal, self-emission background because the Thomson-scattered light is linearly polarized and the background is unpolarized. A Wollaston prism spectrometer provides polarization separation and spectral dispersion, enabling two spectra to be recorded simultaneously in a single shot using a streak camera. A prototype spectrometer was successfully fielded on OMEGA, demonstrating the viability of this approach for characterizing coronal plasmas generated in direct-drive inertial confinement fusion experiments using a 263-nm Thomson probe.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Approaching the intrinsic bandwidth limit: A unified method for balanced homodyne detector design.","authors":"Shaofeng Wang, Zhihao Zhang, Shijun Zhang, Ruifang Dong","doi":"10.1063/5.0349610","DOIUrl":"https://doi.org/10.1063/5.0349610","url":null,"abstract":"<p><p>In this paper, we present a unified method for designing balanced homodyne detectors (BHDs) approaching the intrinsic bandwidth limit, based on either transimpedance amplifier (TIA) or low-noise amplifier (LNA) architectures. Unlike conventional design approaches that consider only the frequency response of the readout circuit, the proposed method incorporates the photodiode carrier transit time. The analysis reveals that when the carrier transit time becomes comparable to the rise time of the readout circuit, the overall detector bandwidth is governed by their combined effect rather than by a single dominant mechanism. In the TIA configuration, accounting for this joint contribution, this method eliminates the systematic bandwidth overestimation inherent in traditional single-mechanism models and consistently explains the observed strong bias-voltage dependence and the reduced optimal feedback capacitance. In contrast, in the LNA configuration, the photodiode carrier transit time becomes the dominant bandwidth constraint, making bias-voltage optimization more critical for bandwidth extension. Guided by the proposed method, a BHD employing an S3883 photodiode and cascaded LNAs was designed and optimized, achieving a 3-dB bandwidth of 210 MHz and a signal-to-noise ratio of 11.3 dB at this frequency. The measured performance agrees well with the theoretical analysis, thereby validating its predictive capability and demonstrating its practical value for high-bandwidth BHD design.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifunctional interferometry-polarimetry for fusion plasma control and physics applications (invited).","authors":"J Chen, D L Brower, T Benedett, G Prabhudesai, M Poulos, W Ding, D Finkenthal, F Khabanov, Suk-Ho Hong","doi":"10.1063/5.0347643","DOIUrl":"https://doi.org/10.1063/5.0347643","url":null,"abstract":"<p><p>Future fusion reactors require robust monitoring of plasma equilibrium and fluctuations to sustain and optimize energy gain, despite severely restricted machine access. We demonstrate a multifunctional interferometer-polarimeter on the DIII-D tokamak that utilizes only four radial chords to simultaneously measure: (a) the interferometric phase shift, (b) the Faraday effect, (c) the Cotton-Mouton effect, (d) density and magnetic fluctuations up to 10 MHz, and (e) fluctuation toroidal mode numbers and vertical wavenumbers. This is achieved via a three-wave, dual-sensor scheme incorporating four vertically and toroidally displaced chords. The Faraday effect measurements constrain the core magnetic equilibrium, directly determining the magnetic axis vertical position. The Cotton-Mouton effect measurement yields a robust line-integrated density measurement free of fringe jumps. Furthermore, fluctuation and wavenumber measurements enable mode localization, facilitating a spatiotemporal survey of multiscale fluctuations from the plasma core to the edge. These results validate a compact interferometry-polarimetry approach capable of delivering comprehensive equilibrium and fluctuation measurements under limited access, supporting the demands of fusion reactors.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149138116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design considerations and forward modeling signal levels for a high dynamic range fusion reaction history diagnostic.","authors":"K D Meaney, H Geppert-Kleinrath, R H Dwyer, B H Haines, Y Kim, R M Malone, H W Herrmann, J Sauppe, M P Springstead, C Trosseille, D Schlossberg, T Morrow","doi":"10.1063/5.0350715","DOIUrl":"https://doi.org/10.1063/5.0350715","url":null,"abstract":"<p><p>A high-dynamic-range fusion reaction history measurement would offer powerful insight into the detailed dynamic evolution, energy balance, hotspot formation, and explosion of igniting fusion hotspots. We review the design principles of potential detector choices to make such a measurement. Results from a forward model using a detector similar to the existing Gamma Reaction History diagnostic, but placed farther from the target chamber and assuming an achieved signal-to-background, are shared. The results show that an optical splitter, a high-gain photomultiplier, and modest attenuation can meet the dynamic-range measurement requirements. The multichannel plate-charge limit, space-charge requirement, voltage, and multiplexing requirement can all be met for yields up to 70 MJ.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149138096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conceptual design of the electron-optics of the magnetic electron recoil gamma-ray spectrometer.","authors":"J H Kunimune, S Huber, S Mackie, E Panontin, N Fensterheim, M Dessena, E Gallo, F Montanari, E Quadrivi, S Vanellone, M Zamboni, J E Rice, R A Tinguely","doi":"10.1063/5.0350449","DOIUrl":"https://doi.org/10.1063/5.0350449","url":null,"abstract":"<p><p>In nuclear fusion reactors, deuterium and tritium are fused together. Most reactions produce a 4He ion and a 14 MeV neutron, while about 2 × 10-5 of them produce a 5He ion and a gamma photon. One of the most important measurements from a fusion reactor is the total fusion power, which can be measured using the 14 MeV neutrons or the gamma-rays. Using both provides two independent measurements, which is valuable for researchers and regulators. Facilities such as JET use scintillators such as LaBr3 to measure gamma-ray emission, but such detectors could struggle with background on high-power reactors such as SPARC and ITER. We propose that a magnetic electron recoil gamma-ray spectrometer (MERGS) can make gamma-ray measurements in these high-background environments. MERGS will consist of a foil that converts photons to electrons via Compton scattering, a magnetic electron-optic system that focuses and disperses the electron beam, and a detector array that counts the electrons and uses their positions to infer their energy. A conceptual design framework of MERGS is presented, along with three numerically optimized electron-optic geometries for three different resolution requirements. Simulations are presented showing that each presented design can meet its requirements. This shows that MERGS can measure the gamma-ray emission spectrum more effectively than scintillators for a variety of price points, enabling improved measurements of fusion power as well as the study of fast ion physics via other nuclear reactions.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149184136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning based spectral fitting and atomic physics corrections for the main ion charge exchange recombination spectroscopy system on the DIII-D tokamak (invited).","authors":"S R Haskey, B Grierson, S K Kim, C Chrystal, A Angulo, Q Pratt, A Jalalvand, E Linsenmayer, L Stagner, N Pablant, A Bortolon, S Smith","doi":"10.1063/5.0350726","DOIUrl":"https://doi.org/10.1063/5.0350726","url":null,"abstract":"<p><p>Rapid and accurate machine learning (ML) based analysis of the Doppler broadened and shifted Balmer-α spectra from the main ion charge exchange recombination spectroscopy (MICER) diagnostic on the DIII-D tokamak has been developed to provide raw measurements of the main ion (typically D+) temperature, toroidal rotation, density, and beam emission based measurements directly from the active Balmer-α spectra. The temperatures and toroidal rotations are typically within 150 eV and 10 km/s of those obtained from the standard least squares fitting approach. The raw measurements are then corrected for systematic errors using a second set of ML models that were trained as inverse surrogates for the FIDASIM three dimensional collisional radiative model. FIDASIM provides a comprehensive forward model of the raw measurements, including atomic physics and spatial smearing effects. At the pedestal top, corrections to the ion temperature are typically 150 eV but can be up to 300 eV. The standard deviation of the difference between the surrogate and the full model based correction is less than 50 eV, with some of this difference due to Monte Carlo noise from the FIDASIM model. 20 000 FIDASIM simulations spanning the relevant DIII-D parameter space were used for the training and validation of the ML model, incorporating variations in ion and electron profiles, as well as variations in the neutral beam injector parameters and magnetic equilibrium mapping. The complexity of the MICER spectra and associated corrections has historically limited analysis to high priority discharges, despite the wealth of information contained in the spectra. These advances have dramatically reduced the analysis time for single discharges from several hours to seconds. The speed-up now allows bulk analysis of thousands of historical discharges acquired by the diagnostic during its 12+ years of operation on DIII-D, enabling a variety of studies, such as those involving H-mode main ion pedestal profiles.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149184162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bayesian profile reconstruction from multi-monochromatic imager data.","authors":"B L Reichelt, M Gatu Johnson, E Gallardo-Diaz, J H Kunimune, W Taitano, K D Meaney, S E Anderson, J A Frenje, C K Li, R Mancini","doi":"10.1063/5.0349351","DOIUrl":"https://doi.org/10.1063/5.0349351","url":null,"abstract":"<p><p>The multi-monochromatic imager (MMI) is a diagnostic instrument that provides spectrally resolved images of inertial confinement fusion experiments centered on emission/absorption from the characteristic lines of mid-Z dopants. Previous methods of analysis required some form of binning across either spectral or spatial axes to create composite images or spectra, respectively. This work takes an alternate approach by generating a synthetic MMI image in an autodifferentiable manner, allowing the use of Hamiltonian Monte Carlo for sampling from the complicated posterior distribution of the parameters describing the plasma. The algorithm is tested with artificial data, and the error bars and reconstructions are shown to match well with the ground truth, with 77% of the fit parameters having overlap between the ground truth and the 90% credible interval of the reconstruction. If the fit discrepancies due to dynamic range imposed on the artificial image are accounted for, the agreement increases to 86% of the fit parameters having overlap between the ground truth and the 90% credible interval of the reconstruction, despite the reconstruction assuming spherical symmetry not present in the test image.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149138066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of a diamond-based in-vessel soft x-ray camera system for the SPARC tokamak.","authors":"S Normile, D Vezinet, B Frandeen, C Perks, F Bombarda, G Verona-Rinati, J E Rice","doi":"10.1063/5.0350758","DOIUrl":"https://doi.org/10.1063/5.0350758","url":null,"abstract":"<p><p>Soft x-ray tomography has been used in tokamaks for decades to interrogate a wide variety of phenomena; however, the standard silicon diodes coupled with beryllium filters will not be able to survive the high heat and neutron fluxes present in burning plasma devices like SPARC. Presented here is the design for a set of soft x-ray tomography cameras that use chemical vapor deposition (CVD) single-crystal diamonds and graphene filters for photodetection. Four of these cameras will be placed in the port plugs of SPARC with a large enough view of the poloidal cross section to enable tomographic inversion and sufficient time resolution to resolve the dynamics of low-m and -n magnetohydrodynamic modes. CVD diamonds have been used successfully for the detection of both vacuum ultraviolet and soft x-ray photons at the Frascati Tokamak Upgrade and have demonstrated the ability to maintain greater than 50% of their initial responsivity at a neutron fluence of 1016 cm-2. The neutron dose in SPARC will exceed this limit, providing a demonstration of how CVD diamonds fail in place while adding value to the early operation of a new tokamak. Numerical simulations indicate that graphene spectral filters will filter nearly as effectively as traditional beryllium ones and are able to resist significantly higher heat fluxes due to graphene's unique thermal properties. Simulated plasma emissivity profiles have been used to optimize both the camera placement and detector properties.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149127908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring effective surface energy in non-equilibrium granular fluids using an innovative orbital tensiometer apparatus.","authors":"Piroz Zamankhan","doi":"10.1063/5.0344099","DOIUrl":"https://doi.org/10.1063/5.0344099","url":null,"abstract":"<p><p>Dense granular media lack a well-established analog of classical liquid tensiometry, although localized interfacial barriers can strongly influence segregation, buoyancy, and intruder stability. Using a calibrated dual-mode orbital calorimeter-rheometer, we show that a partially submerged intruder can serve as an in situ mechanical probe of the grain-mediated restoring response in an orbitally driven dense bed. In the rigid-body core-rotation regime at low peak acceleration, Γ=2.5, and low granular temperature, Tg≈10-7m2s-2, the intruder follows a stable circular orbit with negligible radial drift and intrinsic spin. This kinematic state indicates that the inward centripetal force required in the laboratory frame is balanced predominantly by a localized restoring interaction associated with the air-grain-intruder contact configuration. By combining the measured density-contrast centrifugal demand with the specific interfacial area of the ternary bead mixture and a geometry-calibrated effective radial transmission area, we obtain an effective granular interfacial-stress scale of γgm≈2.38×10-2Jm-2. The inferred value agrees within 1.2% with an independently obtained thermomechanical reference at the corresponding low granular temperature. The result provides a mechanical explanation for the granular Archimedean anomaly, in which the intruder remains stably surface supported while the displaced granular volume supplies less than half of its static weight under a conventional hydrostatic estimate. At the fluidization threshold, Γ=6.02, kinetic thermalization raises the granular temperature to Tg≈10-4m2s-2; the localized restoring configuration is then destabilized, and the intruder exhibits orientation instability, rapid inward migration, intrinsic rotation, and deep convective submersion. A 10 000-trial Monte Carlo analysis yields a coefficient of variation of ∼3.4% under realistic composition tolerances. These results establish a non-invasive, trajectory-based methodology for quantifying an effective localized granular interfacial-stress scale in actively driven dense particulate systems.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}