The Magnetic Recoil neutron Spectrometer (MRS) at the OMEGA laser facility has been routinely used to measure deuterium-tritium (DT) yield and areal density in cryogenically layered implosions since 2008. Recently, operation of the OMEGA MRS in higher-resolution mode with a smaller, thinner (4 cm2, 57-um thick) CD conversion foil has also enabled inference of the apparent DT ion temperature...
Streaked Thomson scattering measurements have been performed on plasma jets created from a 15 µm thick radial Al, Ti, or Cu foil load on COBRA, a 1 MA pulsed power machine. The streaked system enables collecting scattered light from two separate laser pulses separated in time by between 3 and 14 ns. This time difference is created by splitting the initial 3 ns duration, 10 J, 526.5 nm laser...
We have developed a Wolter x-ray imager on the Z Machine to study the emission of warm x-ray sources with x-ray energies above 15 keV. As x-ray energy increases, imaging these sources with both high resolution and signal-to-noise becomes increasingly difficult using existing pinhole camera techniques. A Wolter optic has been adapted from observational astronomy and medical imaging for Z and...
Optical Thomson scattering (OTS) can be used to provide temporally and spectrally-resolved information on under-dense, high temperature plasmas. Scattering from the high-frequency collective excitations of the electrons can be used to constrain the temperature and number density of the electrons based on the width, amplitude and location of resonances in the scattered spectrum. The ion...
Several compact neutron spectrometers are now installed at EAST to obtain the information of fuel ions produced in core plasmas. Here, a stilbene and an NE213 liquid scintillator neutron spectrometers will be discussed. Both of the spectrometers have a horizontal line of sight, while at different positions, and are proved to show good performance when the NBI auxiliary heating system is...
The one-dimensional imager of neutrons (ODIN) at the Sandia Z facility consists of a 10-cm block of tungsten with rolled edges, creating a slit imager width of either 250, 500, or 750 µm. Designed with a 1-m neutron imaging line of sight, we achieve about 4:1 magnification and 500-µm axial spatial resolution. The baseline ICF concept at Sandia is magnetized liner inertial fusion (MagLIF),...
The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a linear plasma device designed to generate divertor-like conditions, yielding electron densities up to ~1020 m-3 and electron temperatures up to ~20 eV. Monochromatic and color Edgertronic Sanstreak SC1 fast visible cameras capture high speed video (<18k fps) of plasma discharges. A 50/50 beam splitter allows both cameras to...
The ECE diagnostic on EAST has been recently upgraded to provide better radial coverage of the plasma and to obtain higher spatial resolution. The lower limit of the frequency band was extended from 104 GHz to 97 GHz by adding a new 8-channel radiometer system, and this ensures a capability of measuring the second harmonic ECE with toroidal magnetic field down to 1.75 T. Also, the existing...
The ITER TIP system requires real time phase demodulation of several radio-frequency (RF) signals to provide accurate electron density measurements essential for plasma control. This is accomplished using a four-channel digital phase demodulator (DPD) constructed using a high-density Field Programmable Gate Array (FPGA) coupled to high-speed analog-to-digital converters (ADC). The DPD samples...
Polarimetric Thomson scattering (TS) is a diagnostic technique useful to increase the accuracy of Te and ne measurements in very hot fusion plasmas such as those of ITER. As for conventional TS the calibration of a polarimetric TS detection system can be performed by using a radiation source internal to the vacuum chamber or, alternatively, Raman scattering from N2 gas filling the vacuum...
Metallic first mirrors will be components for optical spectroscopy and imaging systems in ITER. A comprehensive First Mirror Test (FMT) was carried out in JET with the ITER-Like Wall (ILW): over 60 Mo mirrors facing plasma in the main chamber and in divertor during three ILW campaigns (up to 62 h total). Reflectivity measurements (300-2400 nm) and surface characterization with electron and ion...
Electron Cyclotron Emission Imaging (ECEI) is a diagnostics system which measures 2D electron temperature pro?les of high-temperature plasma. Magnetohydrodynamics(MHD) modes in fusion plasma can be quantitatively studied by of ECEI after calibration (fi?nding the proportional coe?cients of electron temperature to signal amplitude). Conventional calibrating methods are complecated and difficult...
An InfraRed imaging Video Bolometer (IRVB) [1,2] that was previously used on the JT-60U device [3] was installed on KSTAR in 2012. The IRVB had a 2 micron x 7 cm x 9 cm Pt foil blackened with graphite and a 5 mm x 5 mm aperture located 7.5 cm from the foil and had 16 x 12 channels and a time resolution of 10 ms. In 2017 the IRVB was upgraded by replacing the IR camera with a FLIR SC7600...
A tangential X-ray imaging crystal spectrometer (XICS) has been upgraded on J-TEXT tokamak to measure the electron/ion temperature and the plasma toroidal rotation velocity. The XICS has been designed to receive emissions of Ar XVII from −13 cm to +13 cm region with a spatial resolution of 1.8 cm in the vertical direction. The temporal evolution of Ar impurity density profiles after an argon...
Doppler backscattering (DBS) system is a powerful diagnostic for turbulence and ExB flow measurements on tokamaks and other magnetic confinement devices. A W-band multi-channel DBS system has been developed on EAST for the turbulence measurements in core plasma. The DBS system can provide six spatially localized measurement locations by simultaneously launching six frequency probe beams with a...
The WEST (Tungsten [W] Environment in Steady-state Tokamak) tokamak aims at testing ITER divertor components to minimize risks for ITER divertor procurement and operation. It consists in a major upgrade of the superconducting medium size tokamak Tore Supra resulting in changing the circular magnetic configuration to a divertor configuration and implementing an ITER like actively cooled...
The new C-2W experiment (also called “Norman”) at TAE Technologies, Inc. studies the evolution of field-reversed configuration (FRC) plasmas sustained by neutral beam injection. Data on the FRC plasma performance is provided by a comprehensive suite of diagnostics that includes over 600 magnetic sensors, four interferometer systems, multi-chord far-infrared polarimetry, two Thomson scattering...
A new reciprocating scintillator-based fast-ion loss detector (FILD)1 has been installed a few centimeters above the outer divertor of the ASDEX Upgrade tokamak and between two of its lower ELM mitigation coils. The detector head containing the scintillator screen, Faraday cup, calibration lamp and collimator systems are installed on a motorized reciprocating system that can adjust its...
The Large Area Solid Radiochemistry (LASR) collector was deployed at the National Ignition Facility (NIF) in 2017 to collect solid debris samples from NIF targets. The collector was a 20-cm vanadium foil (active area) fielded 50 cm from the NIF target chamber center. The foil was surrounded by a side enclosure, which was covered by an aluminum foil. After a shot, the vanadium and aluminum...
A diagnostic has been fielded on OMEGA to diagnose cross-beam energy transfer (CBET) during implosions. Unabsorbed light from each laser beam is imaged as a “spot” in time-integrated images. Each spot is the end point of a beamlet that originates from a beam profile and follows a path determined by refraction. The intensity varies along that path as a result of absorption and CBET. This...
The behavior of 1 MeV triton has been studied in order to understand alpha particle confinement property in toroidal devices. Time-resolved triton burnup study has been performed by scintillating fiber detectors (Sci-Fi) in large tokamaks [1] and helical systems [2]. The time-integrated triton burnup ratio was successfully measured by activation foils technique in medium sized tokamak [3, 4]....
Crystal x-ray imaging is frequently used in inertial confinement fusion and laser-plasma interaction applications, as it has advantages compared to pinhole imaging, such as higher signal throughput, better achievable spatial resolution and chromatic selection. However, currently used x-ray detectors are only able to obtain a single time resolved image per crystal. The dilation aided...
Impurity injection can be a critical tool for studying impurity transport as well as in understanding physics of plasma-wall interactions in magnetic fusion. Impurity injection can also enable important diagnostic approaches such as spectroscopy and CHERS. While the speed limitations on gas injection and pellet injection are well known, electrostatic and electromagnetic injectors can overcome...
Certain crystal types have internal planes oriented such that they can be used as polarizing beam splitters at specific x-ray energies. Such a crystal can be used, for example, to measure the polarization of the spectral lines emitted by high-temperature plasmas. Generally, the polarization is caused by plasma anisotropy, and measuring it can provide insight into the mechanism that creates the...
The NIF Survey Spectrometer (NSS) which uses the Cauchois geometry has been installed on the Nation Ignition Facility. The NSS is used to measure and L-shell emission from Au Holhraums and K-shell emission from mid to high Z elements from backlighters and bright x-ray sources. The NSS is mounted on a port at the bottom of the chamber with a line of sight that is 37° from vertical. This...
Inertial confinement fusion experiments at NIF utilize a hohlraum, consisting of materials such as gold, uranium, aluminum and/or copper, that can provide potential diagnostic information when coupled with high-yield deuterium-tritium fueled shots. During such experiments, mega-joules of laser energy delivered inside the hohlraum results in its complete destruction and distribution of the...
A Beam Emission Spectroscopy system is being developed and deployed at the HL-2A tokamak to measure local low wavenumber (k_⊥ ρ_I<1) density fluctuations by observing Doppler-shifted emission from a 50 kV deuterium heating neutral beam. High spatial resolution (∆r≤1cm,∆z≤1.5cm) measurements are obtained with a 2 MHz sampling rate. An f/1.6, f=280 mm radiation-resistant in-vacuum objective...
Injection of solid powders has been used in fusion research for various applications, including wall conditioning and pedestal control. Due to the physical properties of various materials, typically, a powder injector is designed and optimized to handle a specific kind of powder. We present a device for controlled injection of a variety of materials in form of powder. The system implements...
Recent indirect drive hohlraum designs for ignition targets on the National Ignition Factify (NIF) are exploring higher laser energy (~ 2 MJ) and power (500 TW) as a way of increasing neutron yield. A consequence is increased laser-plasma interactions (LPI), resulting in increased hot-electrons and cross-beam transfer that moves laser power between laser cones and backscatter in the form of...
The bulk ion-temperature and neutron reaction history are important characteristics of a fusion plasma. Extracting these from a measured neutron-time-of-flight (nTOF) signal, either by convolution or de-convolution methods, requires accurate knowledge of the instrument response function (IRF). This work describes a novel method for obtaining the IRF directly for single D-T neutron...
The plasma current ramp-up and ramp-down that are always along with strong instabilities are the unavoidable processes in the tokamak operation. In order to research these processes in SUNIST(Sino-UNIted Spherical Tokamak), some diagnostic systems that detect the plasma radiation ranging from hard X-rays to visible light are developed. CdZnTe and Silicon drift detectors measure the energy...
We report tests of an alternate technique for constraining MHD equilibrium analysis in tokamak plasmas using internal magnetic field measurements based on |B| measurements from motional Stark splitting of Dα spectral lines emitted by a neutral heating beam (MSE-LS). We compare results using MSE-LS with those of the standard equilibrium analysis technique based on line polarization of the Dα...
Thermonuclear burn history measurements are an important diagnostic of inertial fusion implosion performance, with several instruments developed based on the Cherenkov technique. Depending on the target composition and fuel, several nuclear reactions can produce g rays at different energies. We present a new technique that uses multiple detectors, with varied thresholds, to simultaneously...
A vacuum ultraviolet (VUV) spectrometer spanning wavelength range 5-20 nm was commissioned on Versatile Experiment Spherical Torus (VEST), and wavelength calibration was conducted. The incident lights at 87° diffract at the 1200 g/mm concave grating and form a spectral image on the flat focal plane. A back-illuminated charge coupled device (CCD) of 2048 x 512 pixel array (13.5 x 13.5...
The electron cyclotron emission (ECE) diagnostic system with a 48 channel D-band heterodyne radiometer has been routinely used to measure the electron temperature as well as its radial profile on the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. However, because the overlap between the second and the third harmonic emission frequencies on the high-field side at 2.0 T is not...
Turbulence is an important issue in fusion plasmas as it was found to have a direct link to the particles and heat transports, and hence the confinement performance. In this paper, we report on a turbulence database that was built from measurements of Tore Supra core reflectometer [1] by parametrization of density fluctuation frequency spectra [2], including 350,000 spectra from 6,000...
Coherence imaging (CI) system has been developed to investigate the mechanism of the high-beta plasma formation in a laboratory magnetosphere and plasma particle transport that creates self-organization. The CI system is possible to measure 2D profile of ion temperature and flow velocity in RT-1 magnetospheric plasmas. The CI system utilizes the optical interference by a birefringent crystal...
The outer vessel steady-state magnetic field sensors constitute a part of the ITER magnetic diagnostics. The sensor set consists of a poloidal array of 60 sensors placed on the vacuum vessel outer skin and distributed toroidally in three vacuum vessel sectors. Each sensor unit features a pair of metallic Hall sensors with a sensing layer made of bismuth measuring tangential and normal...
Along the route to the development of a neutral beam injector for ITER, the Padua based SPIDER and MITICA facilities will make use of neutron diagnostics to quantify the homogeneity of the neutral beam profile by measurements of the map of the neutron emission from the beam dump with ad hoc developed Gas Electron Multipliers (GEM). Neutrons are here born from beam target reactions between the...
Fast plasma boundary reconstruction is usually used for real-time control of tokamak plasma. In EAST experiment, the time consuming for boundary reconstruction should be within 1ms to meet the need of real-time control. Fast evolution of cameras in recent years has made them promising tools for diagnostics of Tokamak. The solution presented in this paper consists of a prototype of high-speed...
A high-resolving-power, streaked x-ray spectrometer is being developed and tested on the OMEGA EP Laser System to study temperature-equilibration dynamics in rapidly heated metal. The instrument is based on two diagnostic channels, each with a spherical Bragg crystal. Channel 1 couples a spherical Si220 crystal to an x-ray streak camera. Channel 2 couples a second, identical crystal to an...
Tungsten is an important alternative material to construct the divertor for Tokamak. Due to the effect of the interaction of plasma and the first wall, the first wall, especially the divertor area, will bear high energy to act on the area. Therefore, the detection and diagnosis of the first wall temperature of Tokamak by non-contact temperature measurement is the premise to ensure the safe and...
A Simple near-infrared (NIR) spectrometer for 898 - 2130 nm has recently been applied to Heliotron J plasmas. It adopts symmetrical crossed Czerny-Turner mount equipped with a thermoelectrically cooled 512 channel InGaAs linear sensor. Reciprocal linear dispersion was deduced as 96.37 nm/mm at the center of the detector. Several types of the 2nd order rejection filter are inserted in the...
Recent breakthroughs in the fabrication of small-radii Wolter optics allow NNSA facilities to consider such optics as x-ray diagnostics at 15-50 keV. Recently, LLNL, SNL, the Harvard-Smithsonian Center for Astrophysics and NASA MSFC jointly developed and fabricated the first custom Wolter microscope for implementation in SNL’s Z machine with optimized sensitivity at 17.4 keV. To achieve...
X-ray imaging using shaped crystals in Bragg reflection is a powerful technique used in high-energy-density physics experiments. The characterization of these crystal assemblies with conventional x-ray sources is very difficult because of the required angular resolution of the order of ~10 murad and the narrow bandwidth of the crystal. The 10-J, 1-ps Multi-Terawatt (MTW) laser at the...
A custom motor controlled probe system has been designed to make spatially resolved measurements of temperature, density, flow, and plasma potential in the C-2W inner divertors. Measurements in the inner divertors, which have a radius of 1.7 m and are located on either end of the confinement vessel, are critical in order to gauge exactly how local settings affect the plasma conditions,...
Optimizing neutron imaging lines of sight locations for maximum sampling of the cold fuel density in Inertial Confinement Fusion implosions at the National Ignition Facility S. H. Batha, P. L Volegov, V. E. Fatherley, V. Geppert-Kleinmath, and C. A. Wilde Los Alamos National Laboratory Neutron imaging provides a ready measurement of the shape of the “hot spot” core of an inertial confinement...
The vertical position for elongated, long-pulse tokamak plasmas has to be precisely controlled to optimize performance and prevent disruptions. For a steady-state tokamak reactor, integration of voltage signals arising from flux change is extremely challenging due to zero-offset drift as the measurement is intrinsically inductive. The vertical position of the plasma core current density is...
The Icarus sensor is the newest version of the hybrid-CMOS high-speed x-ray framing camera that has been under development at Sandia for over a decade. Icarus can store 4 images per pixel, has improved soft x-ray detection sensitivity, and an option to independently trigger each half of the sensor to effectively operate as two closely-spaced framing cameras with 1024x256 pixels each. Icarus...
Thomson scattering (TS) system is one of the useful diagnostics to measure electron temperature and density in fusion plasmas. The multi-pass Thomson scattering (MPTS) system is useful technique for increasing the TS signal intensities and improving the TS diagnostic time resolution. The MPTS system developed in GAMMA 10/PDX has a polarization-based configuration with an image relaying system....
Charge exchange spectra from the interaction of fully ionized Carbon impurity ions and injected neutral beam on EAST have been utilized to provide the plasma ion temperature and rotation velocity since the cCXRS was installed on EAST at 2014. However, the concentration of carbon became especially low on EAST with the tungsten divertor in the latest experimental campaign, it is necessary to...
Self-sustaining fusion plasmas must be maintained by the power transfer from fusion born alpha particles to the thermal plasmas during slowing down process. Thus, the confinement of energetic alpha particles is crucial for a thermonuclear reactor in the future. The fast ions are primarily generated by applying auxiliary heating systems such as neutral beam injection and ion cyclotron resonance...
While xenon is the standard propellant for a wide range of plasma thrusters, xenon is expensive and xenon propellant systems require heavy compressed gas tanks, pressure regulators, and other bulky hardware. Iodine has similar mass and is much easier to acquire than xenon. Iodine’s natural state of matter at room temperature is solid and is easily sublimated to gas with a simple heating...
