The DIII-D diagnostic set combines expansions of established systems with implementations of new technologies to improve measurement and associated model validation from the boundary to the core plasma. A recent addition of translatable in-vacuum mirrors controllably alters a laser path within the Thomson Scattering system to adapt to the divertor geometry of particular experiments. The...
A technique for identifying trends in performance degradation for inertial confinement fusion implosion experiments will be discussed. It is based on reconstruction of the implosion core with a combination of low- and mid-mode asymmetries. This technique was applied to the ensemble of hydro-equivalent deuterium--tritium implosions on OMEGA that achieved hot-spot pressures ≈56±7 Gbar.(1) The...
The ITER Plasma Position Reflectometry diagnostic aims to provide measurements of the edge plasma to correct or supplement the magnetics for plasma position control. It consists of five systems, two of which are installed inside the vessel. One of these systems probes the plasma from the high-field side using small pyramidal horns located in the gap between two blankets. Electromagnetic...
Cross-polarization scattering (CPS) provides localized magnetic fluctuation measurements in fusion plasmas based upon the process where magnetic fluctuations scatter electromagnetic radiation into the perpendicular polarization. The CPS system on DIII-D utilizes the probe beam of the Doppler backscattering (DBS) diagnostic and a crossing CPS receive beam, which allows simultaneous density and...
An oxide coated cathode discharge has been characterized using laser-induced fluorescence (LIF) and Planar LIF. The ion temperature was measured in the center of an argon discharge by LIF diagnosis, and the ion density profiles was measured by PLIF diagnosis. Same Laser system consisting of a pumping pulse laser and a tunable dye laser was used in these two measurements. The absorption spectra...
In the development of magnetic confined fusion reactors, the accumulation of impurities is one of the most important subjects for concern because it potentially causes cooling down of the hot plasma. On the other hand, appropriate radiation from localized impurity might mitigate the heat load onto the divertor plate. The tracer-encapsulated solid pellet (TESPEL) has generated certain results...
A new electron cyclotron emission imaging (ECEI) which contains two 16-antenna arrays is being developed on J-TEXT. The mixers in the same antenna array will be driven by the same microwave source. So an optics system is needed to expand the point source to an elongated line source. A traditional spherical local oscillator (LO) optics used to be designed to couple the LO signals and RF power...
Photek are a well-established supplier of microchannel plate (MCP) photomultiplier tubes (PMT) to the inertial confinement fusion community, and have several detectors installed at NIF, Omega (LLE Rochester) and Orion (AWE). The MCP-PMTs produced by Photek have the shortest response time recorded by devices of this type with a small area single MCP PMT having a FWHM of < 100 ps, and in recent...
The lithium beam is an effective diagnostic tool for investigation of stability and particle transport in the pedestal. It was used successfully to measure edge current density12 on DIII-D, achieving qualitative agreement with neoclassical models. Electron density profiles were also measured3. Proposed upgrades will continue these measurements with higher reliability as well as explore new...
In this paper we describe an in-situ calibration technique for the Coherence Imaging Systems (CIS) that measure 2-D images[1] of plasma ion flows[2] on DIII-D. A low power CW diode laser that is tuneable in the range 464-467 nm along with a precision wavemeter (0.01 pm resolution) is used to characterize the interferometer phase as a function of wavelength in the region of CIII (465 nm) and He...
The Crystal Backlighter Imager (CBI) is a monochromatic x-ray radiography diagnostic developed with the goal of imaging the late stages of inertial confinement fusion implosions on the NIF. Initially, CBI could only provide a single radiograph per crystal x-ray optic per experiment given the use of a microchannel plate camera as the detector. The Single-Line-of-Sight (SLOS) framing camera is a...
Diagnostic hole used in indirect-drive inertial confinement fusion cannot be too large to cause severe radiation loss and affect the radiation uniformity in the hohlraum, or too small in case the plasma filling would block diagnostic holes and affect the diagnosis. An elongated hole is chosen as an extreme case to study the plasma movement in diagnostic hole in order to provide reference for...
Laser-irradiating a foil to create a radiation source is a common procedure in high-energy-density experiments. Foil radiation sources are used to drive physical phenomena or diagnostics - such as radiography. Radiography images measure the reduction in intensity of a radiation source through an object, which implies a line-integrated density. Point backlit radiography requires that a pinhole...
A novel type of surface eroding thermocouple (SETC) has been tested and installed in the small angle slot (SAS) divertor of DIII-D for fast local heat flux measurements. The thermojunction of SETC is formed between two thin (10 micron) ribbons, which are filed over to create microfiber junctions. They are able to be exposed directly to the plasma at surface temperatures exceeding 2000℃ and are...
In May 2017, the Opacity Spectrometer (OpSpec) recorded the first X-ray transmission data for iron-magnesium plasmas on NIF, at “Anchor 1” sample conditions (150 eV and 7E21 e-/cc). The OpSpec is a critical diagnostic that will be used to collect data needed to verify recent iron opacity measurements done at the Sandia National Laboratory’s Z-facility. OpSpec diffracts X-rays in the 540-2100...
In an electron beam ion trap, ions are not confined to the electron beam, but rather oscillate in and out of the beam. To determine the time-averaged effective electron density n_e,eff that the ion experiences, the size of the electron beam, the nominal electron density n_e, and the ion cloud size must all be measured. We use imaging techniques in the extreme ultraviolet (EUV) and optical to...
Heating, current drive, and partial fueling from neutral beam injection are essential to the sustainment of C-2W field-reversed configuration (FRC) plasmas. C-2W has eight 1.7 MW neutral beams (total of 13.6 MW), each capable of providing an elliptically-shaped beam of 15 keV hydrogen neutrals for 30 ms. To maximize the effectiveness of neutral beam injection, duct losses must be minimized....
We report on a potentially significant improvement in the design of vacuum gauges of the so-called ASDEX-type. Such gauges are in wide use in fusion experiments, but they nonetheless suffer from a relatively high failure rate when operated at high magnetic field strengths for long times. For example, in Wendelstein 7-X only 6 of 18 pressure gauges survived plasma operation in the operational...
A corresponding photoelectric detection system was initiatively designed for fast-ion D-alpha spectrum diagnosis on Experimental Advanced Superconducting Tokamak (EAST). The biggest challenge in designing is to improve the signal-to-noise ratio to detect the FIDA signal in the same spectral range from the other light sources when the neutral beam is injected. The new photoelectric detection...
The lithium tokamak experiment has undergone an upgrade to LTX-β, a major part of which is the addition of NBI. NBI has allowed for a CHERS system to be installed. The CHERS system will measure impurity concentrations (mainly lithium), ion temperature, and toroidal velocity. Previously on LTX these parameters relied on passive spectroscopy and inversion techniques or were unavailable. Typical...
The development of high speed imaging detectors is crucial for high-temperature plasma characterization and optimization. These detectors must perform within many strict parameters, such as precise timing, high spatial resolution, low noise, high gain, and fast gating. We present test results on a picosecond gated optical intensifier (GOI) that meets these requirements. The detector was...
Neutral beam injected fast ions play a dominant role in the C-2W plasma at TAE, heating the plasma and sustaining the field-reversed configuration, making the diagnosis of these fast ions a major pillar of our research program. Recently, a collaboration between TAE Technologies and the University of Wisconsin was conducted to develop a method for measuring a fast changing fast ion spatial...
Many tokamak devices utilize high-power neutral beams for various beam-based active spectroscopic diagnostics such as motional Stark effect (MSE). For higher heating performance, it is customary for the neutral beam injection (NBI) to be made with a multiple number of ion sources, which often times conflicts the environment that the active spectroscopic systems desire. This is mainly because...
The streaked Orion high-resolution x-ray spectrometer (STOHREX) is a combination and adaptation of the time integrating OHREX spectrometer front end, currently operating at the ORION laser facility, and a sub-pico second LLNL streak camera. The new instrument is being developed to gain temporal information on spectral lines produced in short pulse heated plasmas at the ORION laser facility. ...
Newly developed large-area pixelated two-dimensional detector and two-crystal assemblies were deployed for the first time on tokamaks to enable time-resolved Bragg-diffracted x-ray imaging with good framing rate and water-cooling capabilities for in-vacuum long-pulse operations. High-quality Helium-like and Hydrogen-like Argon spectra have been observed simultaneously for the first time on a...
A versatile combination Doppler Backscattering (DBS) and Cross-Polarization Scattering (CPS) diagnostic for the C-2W Beam-Driven Field-Reversed Configuration is described. This system is capable of measuring density fluctuations and perpendicular magnetic field fluctuations across a wide wavenumber range, with typical resolution ≤ 0.4. Four tunable frequencies (26 GHz ≤ f ≤ 60 GHz...
At large laser faculties such as OMEGA and NIF, x-ray spectrometers are provided by the facility. These spectrometers are often used as backlighter monitors or to diagnosis plasma conditions. Often the calibration of these spectrometers is unknown or out of date. As a remedy to this for flat crystal spectrometers, a model with a ray trace method for is described which can be used with only...
Shenguang-III (SG-III) laser facility is a new high power laser facility in China. It is built for the inertial confinement fusion (ICF) experiments with 100kJ laser driven. The X-ray streak camera is required in many experiments, such as the implosion trajectory measurement, the plasma movement with X-ray emission and the time-resolved X-ray spectrum measurement. The X-ray streak cameras with...
The Beam Emission Spectroscopy (BES) diagnostic measures long wavelength density fluctuations by measuring Doppler shifted H-alpha/D-alpha emission arising from collisions between heating neutral beam particles and background plasma electrons, ions and impurities. A novel integrated compact 2D BES system is currently being designed, tested and built for HL-2A and future HL-2M tokamak. A high...
Magnetized Liner Inertial Fusion (MagLIF) compresses a preheated, magnetized, deuterium-filled Be cylinder, using magnetic direct drive from high-current pulsed power devices such as Sandia’s Z-machine. A major complication of existing MagLIF targets is the presence of a solid-density window that a preheat laser must pass through before being absorbed in the low-density gas that comprises the...
An alternative calibration method has been developed for Doppler Coherence Imaging Spectroscopy (CIS). CIS is an interferometric technique for high-speed imaging of impurity flow in the tokamak scrape-off layer, where the flow zero is calibrated using a reference phase image at the rest wavelength of the targeted emission. Recent work at DIII-D has demonstrated that accurate extrapolation of...
Neutron time-of-flight (nToF) diagnostics at the NIF were recently outfitted with novel Cherenkov detectors. A quartz radiator delivers sub-nanosecond response time and is optically coupled to a MCP-PMT with gain ~1 to 10^4. Capitalizing on its fast response time, its sensitivity to gamma particles, and customized digitization, these systems provide better than 50 ps precision in measured...
Warm dense Matter (WDM), intermediate between solids and plasmas, exhibits properties common to both. Due to its complexity, it is vital to directly measure the dynamic structure factor, providing information on electron-electron and ion-ion coupling. The high frequency plasmons, with an energy transfer of ~1-10 eV, have been successfully investigated using X-ray spectroscopy at large laser...
Material clusters of different sizes are known to exist in high-temperature plasmas due to plasma-wall interactions. The facts that these clusters, ranging from sub-microns to above mm in size, can move from one location to another quickly, and that there are a lot of them, make high-speed imaging and tracking one of the best, effective, and sometimes only diagnostic. A machine learning...
C-2W field-reversed configuration (FRC) experiments [1] are focused to resolve major physics issues facing the future of FRC devices. To achieve these goals, it is essential to measure the plasma equilibrium dynamics and monitor plasma fluctuations. One of the critical diagnostics under development is a 14-chord three-wave far infrared (FIR) laser interferometry and polarimetry system, which...
A phase contrast imaging (PCI) diagnostic [1] was developed and installed for the Wendelstein 7-X (W7-X) OP1.2a campaign which took place in the latter half of 2017 [2]. The PCI technique applied to plasmas provides measurements of coherent and turbulent fluctuations in the electron density. These fluctuations act as a phase grating to the incident coherent light from a CO2 laser. Collection...
Correlation techniques have been successfully utilized for plasma diagnostics like electron cyclotron emission to reduce measurement noise. We present the first application of such a technique to interferometer-polarimeter operation on the Madison Symmetric Torus. The MST FIR interferometer-polarimeter diagnostic utilizes 11 vertical chords with a spatial resolution of 7-8 cm and a heterodyne...
Spectrally and temporally resolved x-ray emission of highly charged mid-Z ions is utilized for characterizing the electron temperature (Te) in the equatorial region of a laser-driven ignition-type NIF hohlraum. Line-intensity measurements are used to infer the ionization balance and electron temperature. Spectral analysis shows a peak electron temperature of Te = (2.7 ± 0.4) keV at the...
Among the major goals of ITER project is the study of fast ions and alpha particles behavior. Fast ions with anisotropic velocity distribution functions (VDF) can be created by additional plasma heating such as NBI and ICRH. A charge-exchange atoms and neutrons spectrometer with tangential lines of sight (for short, Tangential Neutral Spectrometer, TNS) for ITER has been developed and is...
Quantitative understanding of the physics of dust or granular matter transport significantly impacts several aspects of burning plasma science and technology. This work takes machine vision techniques popular in robotics and self-driving cars and applies them to identification and analysis of microparticles generated from exploding wires. Using only the image frames and knowledge of the...
Fusion reaction history and ablator areal density measurements for Inertial Confinement Fusion experiments at the National Ignition Facility are conducted using the Gamma Reaction History diagnostic (GRH-6m). Future Gas Cherenkov Detectors (GCD) will ultimately provide ~200x more sensitivity, reduce the effective temporal resolution from ~100 to ~10 ps and lower the energy threshold from 2.9...
Wendelstein 7-X (W7X) is equipped with multiple reflectometry systems which are dedicated to measure localized density fluctuations. Two monostatic Doppler reflectometry (DR) systems (V/W-band) with fixed tilt angles allow to infer the radial electric field Er in the range r/a > 0.7 which extends also into the SOL region where strong modifications of the magnetic topology for the different...
At the National Ignition Facility, storage phosphor imaging plates (IP) are used extensively for recording x-rays, charged particles and neutrons. For x-ray imaging and spectroscopy, absolute and relative calibrations are important for extracting plasma information from the diagnostics. We use Fuji MS SR and TR image plates that have been cut to fit custom diagnostic envelopes. The image...
Liquid-metal plasma facing components (LM-PFC’s) could provide fusion reactors with improved tritium breeding capabilities, enhanced power removal, and ‘self-healing’ interior surfaces that are immune to both radiation damage and thermal stress. During reactor operation, fast-moving, smooth-flowing LM-PFC surfaces are preferred since surface waves may cause non-uniform heating of the LM-PFC...
The proposed work is devoted to design, construction and testing advanced imaging diagnostics that will be able to perform the global SXR imaging ultimately aimed at both high Z and light impurities tracking. The detection structure is based on triple GEM amplification structure followed by the pixel readout electrode. The efficiency of detecting unit was adjusted for the radiation region of...
For the stellarator W7-X, spectroscopic systems detecting line radiation of light impurities and hydrogen from near UV to near IR for quantitative studies at two different divertors have been prepared. These systems comprise of various spectrometers with cooled CCD cameras as well as photomultipliers with interference filters for fast measurements (up to 100 kHz). At both positions, a...
The current Particle X-ray Temporal Diagnostic has been used to simultaneously measure X-ray-emission and nuclear-reaction histories in Inertial Confinement Fusion (ICF) implosions at OMEGA. Through time-resolved measurements of the X-ray continuum, the time-evolution of the electron-temperature [Te(t)] can be inferred. Obtaining this information is essential in our efforts to understand the...
RF system-on-chips permit mm-wave fusion plasma diagnostics to address major challenges: space inefficiency, inflexible installation, performance, and prohibitively high cost of conventional discrete component assemblies as higher imaging resolution and data accuracy are required and achieved by significant increases in numbers of channels. Today, CMOS technology can operate at >hundreds of...
Two scintillating fiber (Sci-Fi) detectors have been operated in the first deuterium campaign of the Large Helical Device (LHD) in order to investigate the time evolution of the triton burnup through secondary 14 MeV neutron measurement. Two detectors use scintillating fibers of 1 mm diameter embedded in an aluminum matrix with length of 10 cm, which connect to the magnetic field resistant...
A Neutron Camera (NC) was used on the Mega Ampere Spherical Tokamak (MAST) to measure the DD neutron emissivity along four collimated lines of sight, two on-axis and two off-axis, all viewing the plasma in tangential direction. The encouraging results obtained suggested that an upgraded NC for MAST-U would provide fundamental information for the study of fast ion physics. This work describes...
CO2 laser interferometer is one of the most important diagnostics to evaluate line averaged electron density of magnetic confinement plasmas. In order to align and stabilize the beam axis, the beam axis and profile should be monitored. So far, a thermal imaging plate (TIP) on the market (Macken instruments Inc.) has been used as the beam profile monitor. This TIP is using thermal quenching...
Performance of the diagnostics suite device and initial observation results of collisional merging experiments in the FAT-CM device are presented. The FAT-CM device, consisting of two FRTP formation sections and a confinement section, has been developed to investigate the collisional merging process and the propagation properties of low-frequency wave in the high-beta compact toroid of...
Understanding of the influence of the edge toroidal rotation on the L-H transition power threshold is important for improving the plasma performance of future fusion devices. An edge toroidal charge exchange recombination spectroscopy (eCXRS) diagnostic has been deployed recently on the Experimental Advanced Superconducting Tokamak (EAST), providing the edge toroidal rotation. Experimental...
The Gamma Ray Imager (GRI) is a novel diagnostic providing 2D tangential imaging of bremsstrahlung radiation from runaway electrons (RE) in the DIII-D tokamak. GRI is a lead pin-hole camera utilizing a 2D array of Bismuth Germanate (BGO) detectors. It is located at the DIII-D midplane and possesses up to 123 tangential sight-lines spanning the entire plasma poloidal cross-section. BGO...
The Thomson scattering (TS) diagnostic on the Proto-MPEX at ORNL has been upgraded to simultaneously measure electron temperature (Te) and density (ne) at two axial locations. After the first pass through the vacuum vessel, the existing laser beamline is re-collimated in atmosphere and rerouted into the vacuum vessel for the second pass. The upgrade will help diagnose axial Te and ne gradients...
A Heavy Ion Beam Probe (HIBP) diagnostic on the Wendelstein 7-X (W7 X) superconducting stellarator will provide a unique ability to advance understanding of neoclassical and turbulent particle and energy transport. We present results of beam simulations which show that measurement signal levels, calculated using neo-classical density and temperature profiles with central densities up to 1020...
