Review of Scientific Instruments最新文献

{"title":"A novel high frequency, high bandwidth, three phase Mach-Zehnder optical data link.","authors":"Logan Norman, Hermann Geppert-Kleinrath, Kevin Meaney, Yongho Kim","doi":"10.1063/5.0230575","DOIUrl":"https://doi.org/10.1063/5.0230575","url":null,"abstract":"<p><p>In inertial confinement fusion, hydrogen isotopes are fused together under high pressures and temperatures. Typically, the duration of these experiments is incredibly short, on the order of around 60-150 ps. Due to the high radiation environment, a detector's signal is typically data linked far distances to a protected location. The diagnostic challenge for fusion reaction history measurements is to measure signals of interest maximizing dynamic range while also maintaining time resolution on the order of 10 ps. In this work, we present a new experimental optical data link used to efficiently transport diagnostic signals over great distances to the recording system while not restricting the dynamic range. The concept of a three phase Mach-Zehnder modulator system is introduced as well as a description of the physical prototype. The initial results from testing at the OMEGA facility show that this system is a viable method for signal transportation.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"95 12","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802111","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":"Development of new gas analytical technique for infrared spectroscopy combined with differential pressure measurements.","authors":"Dock-Chil Che, Satoru Muramatsu, Shuntaro Azuma, Yoshiya Inokuchi","doi":"10.1063/5.0234925","DOIUrl":"https://doi.org/10.1063/5.0234925","url":null,"abstract":"<p><p>A new gas analytical technique for infrared laser spectroscopy combined with differential pressure measurement (IR-DP) is developed. The basic idea of this technique is that the absorption process of molecules by laser irradiation is monitored as the pressure enhancement in a gas cell by use of a differential pressure gauge. The system is composed of a tunable IR laser system, sample cell, differential pressure gauge, and data accumulation system. Using this system, the measurements of the IR absorption spectra for cyclohexane (50 ppm) and ammonia (100 ppm) are demonstrated. By comparison of the current IR-DP spectra with conventional Fourier-transform infrared spectra, the spectral resolution is found to be about 3 cm-1, reflecting the laser resolution. Furthermore, the estimated pressure enhancement based on a simple model is consistent with the experimental results. These results suggest that the newly developed IR-DP technique is one of a powerful tool for trace gas detection.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"95 12","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802119","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":"A platform for non-local thermodynamic equilibrium atomic physics research using the buried layer target approach at a kJ level laser facility.","authors":"M Fraenkel, E V Marley, Y Ehrlich, Z Henis, J Emig, A Meir, Y Ferber, D Guttman, G Strum, D Kartoon","doi":"10.1063/5.0235458","DOIUrl":"https://doi.org/10.1063/5.0235458","url":null,"abstract":"<p><p>We present a design and first use of a kJ level laser facility for research of non-local thermodynamic equilibrium atomic physics using the buried layer target method. The target design included a metal layer buried inside a plastic tamper with thicknesses tailored to the expected laser intensities. The target was illuminated from each side by two laser beams with intensities of 0.5-5 × 1014 W/cm2. The advanced diagnostic suite included static and time-resolved imagers and spectrometers with various spectral resolutions. A 3D printed dual elliptically curved spectrometer is presented, and its results are compared to a traditional crystal spectrometer. Experimental results and radiation hydrodynamic simulations demonstrate that the target achieved the desired thermodynamic conditions of ne ≈ 1021-1022 cm-3 and Te ≈ 1-2 keV.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"95 12","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142829047","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":"Response function measurement for a non-destructive gas-sheet beam profile monitor.","authors":"Ippei Yamada, Junichiro Kamiya","doi":"10.1063/5.0234781","DOIUrl":"https://doi.org/10.1063/5.0234781","url":null,"abstract":"<p><p>A gas-sheet beam profile monitor enabling non-destructive two-dimensional profile measurements of a high-intensity beam by capturing an image of a beam-induced fluorescence was developed. For quantitative profile measurements, the monitor's response function comprising, e.g., the gas sheet density distribution and the detector's sensitivity distributions must be experimentally clarified because the monitor output is a converted profile with the response function. A response function measurement method was devised based on the beam-profile-measurement method formula of the monitor. The response function was obtained by injecting a thin electron beam into the developed monitor and scanning its center position in transverse. The measured response function was evaluated by the J-PARC 3 MeV, 60 mA H- beam profile measurement. The 2-D beam profile was successfully reconstructed with the measured response function within the 2.74% residual of the least-squares method and 6.01% experimental statistic deviation. The projected 1-D profiles agreed well with those measured using a wire-scanning-type profile monitor.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"95 12","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142897269","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":"A compact and fast radio-frequency source for efficient Raman sideband cooling.","authors":"Liren Pang, Zhiyu Ma, Biao Wang, Rui Gong, Songquan Wei, Hongli Liu, Wenhao Yuan, Ke Deng, Jie Zhang, Zehuang Lu","doi":"10.1063/5.0235305","DOIUrl":"https://doi.org/10.1063/5.0235305","url":null,"abstract":"<p><p>A compact and fast radio-frequency (RF) source developed for Raman sideband cooling (RSBC) in trapped ion and cold atom experiments is presented. The source is based on direct digital synthesizer, advanced real-time infrastructure for quantum physics, and field programmable gate array. The source has a frequency switching speed of 40 ns and can output continuous μs-level time sequences for RSBC. The maximum output frequency of the source is 1.4 GHz. The RF source is capable of pre-writing data for eight channels. As a demonstration, the RF source is applied to our 25Mg+-27Al+ ion pair optical clock experiment. In order to cool down the ion pair to the vibrational ground state, two-order RSBC is applied to the 25Mg+ ion. As a result, the ion pair motions in the three X, Y, and Z directions are all cooled to the vibrational ground state efficiently, demonstrating the feasibility of this technique. The developed RF source can be widely implemented for other cold atom experiments.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"95 12","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142906943","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":"Analyzing the effects of reflections on optical diagnostics in the main chamber and divertor of WEST (invited).","authors":"C A Johnson, A Diaw, E A Unterberg, N Fedorczak, P Tamain","doi":"10.1063/5.0219546","DOIUrl":"https://doi.org/10.1063/5.0219546","url":null,"abstract":"<p><p>Understanding the erosion of plasma facing components in fusion devices is vital, particularly for long-pulse operations. This study presents the application of synthetic optical diagnosis on the all-W WEST tokamak. The analysis reveals reflections as significant contributors to measured emission, varying across main chamber limiters and divertor targets. Reflections at divertor locations can be up to 50% of measured emission while 95% at limiter locations. Oxygen is investigated as a proxy for low-Z species and underscores the importance of reflections in interpreting optical diagnostics, especially for validating plasma-material interactions and scrape-off layer impurity transport codes. As more fusion devices adopt full metal walls, the accurate assessment of reflections will become increasingly crucial for erosion analysis and plasma control.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"95 12","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142771902","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":"Soft x-ray tomography using L1 regularization for MHD modes with limited sight lines in JT-60SA.","authors":"T Bando, M Takechi, S Ohdachi","doi":"10.1063/5.0232912","DOIUrl":"https://doi.org/10.1063/5.0232912","url":null,"abstract":"<p><p>Soft x-ray (SX) tomography is a useful diagnostic in fusion research, and a multi-channel SX diagnostic will be installed in JT-60SA, the largest elongated tokamak in the world. However, in the SX diagnostic of JT-60SA, plasmas will be only viewed from the low field side and the upper side of plasmas; the sight lines are limited, which would be common in future devices as well as JT-60SA. This kind of limited sight lines is not preferred for SX tomography to investigate the spatial structure of magnetohydrodynamics (MHD) modes because inadequate information of plasmas makes artifacts in the reconstructed SX profiles. One of the solutions to reduce the artifacts is to employ L1 regularization, which gives the essential and sparse contributions [Kaptanoglu et al., Phys. Plasmas 30, 033906 (2023)]. In this study, as a first topic, the applicability of L1 regularization to reduce the artifacts in SX tomography with limited sight lines is investigated with traditional L2 regularization for a high beta scenario of JT-60SA where MHD modes would occur. Here, as a series of basis functions, the Fourier-Bessel series (FBS) is employed because FBS has the poloidal Fourier modes explicitly. A disadvantage of FBS is that the accurate equilibrium inside the last closed flux surface (LCFS) is needed; interior measurement such as the motional Stark effect measurement is required, which is not always available during a whole discharge. The second topic of this study is to investigate other appropriate basis functions to study the spatial structure of MHD modes in elongated tokamak plasmas. Here, we introduce Saito's Laplacian eigenfunction (LEF). Saito's LEF can be calculated if LCFS is given and the LEF is expected to show the explicit poloidal Fourier mode. Because the calculation of LCFS with magnetic measurements is a basic task of plasma operations, Saito's LEF may be used anytime. Our investigation showed that L1 regularization can strongly improve the SX tomography with the traditional L2 regularization having FBS/LEF and would be effective against other tomographic problems in fusion devices.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"95 12","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142771954","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":"Novel predefined-time stability theory and its application in sliding mode control of synchronizing chaotic systems.","authors":"Jingang Liu, Ruiqi Li","doi":"10.1063/5.0241261","DOIUrl":"https://doi.org/10.1063/5.0241261","url":null,"abstract":"<p><p>Aiming at predefined-time synchronization for chaotic systems, a new predefined-time sliding mode control method is proposed. First, based on the definition of predefined-time stability, a novel predefined-time inequality is proposed, along with a detailed mathematical proof. This inequality differs from existing Lyapunov inequalities and offers greater flexibility. Second, a new sliding mode surface and sliding mode controller are proposed based on this inequality. Since the sliding mode controller introduced in this paper is tunable, the actual convergence time can be adjusted freely within the predefined time. Finally, two sets of numerical simulations demonstrate that the proposed method offers advantages in terms of short synchronization time and high regulatory performance compared to traditional predefined-time sliding mode control, finite-time sliding mode control, and fixed-time sliding mode control.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"95 12","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142771937","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":"A waveguide branch-line crossover based on metal gratings.","authors":"Xiaoyi Liao, Rongyu Yang, Yongheng Zheng, Xiangcheng Qian, Chen Zhao","doi":"10.1063/5.0230286","DOIUrl":"https://doi.org/10.1063/5.0230286","url":null,"abstract":"<p><p>A waveguide branch-line crossover with broad bandwidth is designed for beam-forming networks in millimeter wavebands. To realize the power coupling between two parallel branch lines, a substrate with metal gratings patched replaces the common E-plane waveguide wall. Compared with the traditional crossover with coupling vias, the metal gratings achieve continuous and efficient power coupling, endowing the proposed crossover with advantages in compactness and broad bandwidth. A simulation-assisted transfer-matrix approach is used to rapidly estimate and optimize the parameters of the crossover. The coupling obtained from the simulation is over -0.5 dB from 32.1 to 39.1 GHz, with isolation greater than 15 dB and reflection less than -20 dB. A prototype is fabricated, and the measurement results agree with the simulation results, demonstrating that the proposed crossover is a promising candidate for millimeter-wave beamforming networks.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"95 12","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802115","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":"Spurious radiated power signal following massive material injections in JET and the effect of neutral gas pressure on resistive bolometers.","authors":"N Schoonheere, C Reux, H Meister, P Beyer, P Carvalho, I Coffey, K Lawson, P Puglia, U Sheikh","doi":"10.1063/5.0224783","DOIUrl":"https://doi.org/10.1063/5.0224783","url":null,"abstract":"<p><p>Massive material injections in the JET tokamak have been observed to substantially affect resistive bolometer measurements, resulting in a spurious radiated power signal proportional to the quantity injected and reaching up to 8 MW. These bolometers are calibrated and designed to operate in near vacuum but certain scenarios requiring large gas injections can push the neutral pressure past nominal values. This study demonstrates that the bolometry measurement can be affected at neutral pressures above 0.1 Pa following injections with standard gas valves, shattered pellet injections, and particularly massive gas injections. The power measurement of resistive bolometers is based on the temperature difference between a measurement sensor exposed to radiation and a shielded reference sensor. We employ a thermal conductivity model to demonstrate that the conduction through the gas and the distinct geometries between the sensors can affect their cooling efficiency. This additional cooling pathway, coupled with the Joule heating from the applied voltage causes the equilibrium temperatures of the sensors to diverge. Being the very basis of the measure, this temperature difference induces a signal that is erroneously interpreted as radiated power. Experiments show large discrepancies in the response to neutral pressure among bolometer channels, attributed to variations in channel physical parameters. Nonetheless, the modeled total radiated power reproduces the experimental measurements within an order of magnitude, affirming the sensitivity of resistive bolometers to neutral pressure and gas species.</p>","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":"95 12","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807652","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}