Development of a YAG laser system for the edge Thomson scattering system in ITER

Hatae, T.; Yatsuka, E.; Hayashi, Takashi; Yoshida, Hidetsugu; Ono, Taeko; Kusama, Y.

doi:10.1063/1.4738658

Cited by 24 publications

(13 citation statements)

References 6 publications

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“…The prototype is a 1064 nm, 5 J, 100 Hz double beam system, thus each of A-and B-line operates at 2.5 J and the frequency of 100 Hz. 4 During the 2012 campaign, however, we used the B-line only with the laser energy reduced down to 2 J at 100 Hz because of a minor failure in the optical component test after its delivery from JAEA. Thus, for the 2012 KSTAR campaign, the 2 J laser beam was injected into the KSTAR vacuum vessel through eight mirrors and focused on the targeted region by the convex lenses.…”

Section: Experiments and Datamentioning

confidence: 99%

“…Polarimetry is a well known technique used to determine the internal magnetic field structure in tokamaks since it was first proposed by DeMarco and Segre. 2 Polarimeter system, with either poloidally or toroidally viewing geometry, has been successfully demonstrated on many devices including TEXTOR, 3 TEXT, 4 JET, 1 MST, 5, 6 J-TEXT, 7 and Alcator C-Mod. 8 EAST, as a fully superconducting tokamak, 9, 10 is aimed at long pulse (60-1000 s) high-performance plasma discharge operation.…”

Section: Introductionmentioning

confidence: 99%

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A 1 kA-class cryogen-free critical current characterization system for superconducting coated conductors

Strickland

Hoffmann

Wimbush

2014

Review of Scientific Instruments

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A cryogenic electrical transport measurement system is described that is particularly designed to meet the requirements for routine and effective characterization of commercial second generation high-temperature superconducting (HTS) wires in the form of coated conductors based on YBa2Cu3O7. Specific design parameters include a base temperature of 20 K, an applied magnetic field capability of 8 T (provided by a HTS split-coil magnet), and a measurement current capacity approaching 1 kA. The system accommodates samples up to 12 mm in width (the widest conductor size presently commercially available) and 40 mm long, although this is not a limiting size. The sample is able to be rotated freely with respect to the magnetic field direction about an axis parallel to the current flow, producing field angle variations in the standard maximum Lorentz force configuration. The system is completely free of liquid cryogens for both sample cooling and magnet cool-down and operation. Software enables the system to conduct a full characterization of the temperature, magnetic field, and field angle dependence of the critical current of a sample without any user interaction. The system has successfully been used to measure a wide range of experimental and commercially-available superconducting wire samples sourced from different manufacturers across the full range of operating conditions. The system encapsulates significant advances in HTS magnet design and efficient cryogen-free cooling technologies together with the capability for routine and automated high-current electrical transport measurements at cryogenic temperatures. It will be of interest to both research scientists investigating superconductor behavior and commercial wire manufacturers seeking to accurately characterize the performance of their product under all desired operating conditions.

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Section: Experiments and Datamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A 1 kA-class cryogen-free critical current characterization system for superconducting coated conductors

Strickland

Hoffmann

Wimbush

2014

Review of Scientific Instruments

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“…We defined simple predicates for diagnostic systems to validate our concept. The predicates were applied to preliminary design the laser system for ETS [14]. A schematic of the process flow diagram of the laser system is shown in Fig.…”

Section: Application To Ets and Validation Of The Resultsmentioning

confidence: 99%

New Proposal on the Development of Machine Protection Functions for ITER Diagnostics Control

Yamamoto

Yatsuka

Hatae

et al. 2016

Plasma and Fusion Research

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There is a need to develop ITER instrumentation and control (I&C) systems with high reliabilities. Interlock systems that activate machine protection functions are implemented on robust wired-logic systems such as programmable logic controllers (PLCs). We herein propose a software tool that generates program code templates for the control systems using PLC logic. This tool decreases careless mistakes by developers and increases reliability of the program codes. A large-scale engineering database has been implemented in the ITER project. To derive useful information from this database, we propose adding semantic data to it using the Resource Description Framework format. In our novel proposal for the ITER diagnostic control system, a guide words generator that analyzes the engineering data by inference is applied to the hazard and operability study. We validated the methods proposed in this paper by applying them to the preliminary design for the I&C system of the ITER edge Thomson scattering system.

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“…4 During the 2012 campaign, however, we used the B-line only with the laser energy reduced down to 2 J at 100 Hz because of a minor failure in the optical component test after its delivery from JAEA. Thus, for the 2012 KSTAR campaign, the 2 J laser beam was injected into the KSTAR vacuum vessel through eight mirrors and focused on the targeted region by the convex lenses.…”

mentioning

confidence: 99%

Edge electron density profiles and fluctuations measured by two-dimensional beam emission spectroscopy in the KSTAR

Nam

Zoletnik

Lampert

et al. 2014

Review of Scientific Instruments

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Beam emission spectroscopy (BES) system in Korea Superconducting Tokamak Advanced Research (KSTAR) has recently been upgraded. The background intensity was reduced from 30% to 2% by suppressing the stray lights. This allows acquisition of the relative electron density profiles on the plasma edge without background subtraction from the beam power modulation signals. The KSTAR BES system has its spatial resolution of 1 cm, the temporal resolution of 2 MHz, and a total 32 channel (8 radial × 4 poloidal) avalanche photo diode array. Most measurements were done on the plasma edge, r/a ∼ 0.9, with 8 cm radial measurement width that covers the pedestal range. High speed density profile measurements reveal temporal behaviors of fast transient events, such as the precursors of edge localized modes and the transitions between confinement modes. Low background level also allows analysis of the edge density fluctuation patterns with reduced background fluctuations. Propagation of the density structures can be investigated by comparing the phase delays between the spatially distributed channels.

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Development of a YAG laser system for the edge Thomson scattering system in ITER

Cited by 24 publications

References 6 publications

A 1 kA-class cryogen-free critical current characterization system for superconducting coated conductors

A 1 kA-class cryogen-free critical current characterization system for superconducting coated conductors

New Proposal on the Development of Machine Protection Functions for ITER Diagnostics Control

Edge electron density profiles and fluctuations measured by two-dimensional beam emission spectroscopy in the KSTAR

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