The Design of an Electron Bernstein Wave Heating System for the TJ-II Stellarator

Fernández, Á.; Sarksyan, K. A.; Matveev, N. V.; Castejón, F.; Cappa, Á.; Kharchev, N. K.; Tereshchenko, M.; Starshinov, N. N.; Martı́n, Rosario

doi:10.13182/fst04-a572

Cited by 7 publications

(3 citation statements)

References 4 publications

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“…With the impending coming on line of the second of TJ-II's two neutral beam injectors [16], as well as an Electron Bernstein Wave Heating system [17], the CXRS-DNBI diagnostic will be a powerful tool for the different heating scenario envisaged. Moreover, in the near future upgrades to the active diagnostic will be made in order to increase its scientific return.…”

Section: Discussionmentioning

confidence: 99%

A Systematic Study of Impurity Ion Poloidal Rotation and Temperature Profiles Using CXRS in the TJ-II Stellarator

Carmona¹,

McCarthy²,

Tribaldos³

et al. 2008

Plasma and Fusion Research

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A concise systematic study of impurity parameter profiles (impurity ion temperatures and poloidal velocities) measured under different plasma conditions has been carried out in the TJ-II stellarator using an active spectroscopic diagnostic system covering a large section of the central plasma minor radius, from r/a = 0.3 to 0.85, with high spatial resolution. For this, plasmas using hydrogen as the working gas were created and maintained using electron cyclotron resonance heating (from 400 to 500 kW) and line-averaged densities between 0.4 and 0.9 × 10 19 m −3 were achieved. In the first instance, it is noted that ion temperature profiles tend to be flat across the accessible plasma radius, whilst a transition in the poloidal velocity from the ion to the electron diamagnetic direction is observed with increasing density. At the same time, the shear point for impurity velocity is seen to propagate outwards towards the plasma edge. Similarly, at a fixed density, a similar tendency is observed when raising the injected heating power. These results together with the behaviour of the impurity temperatures for the same conditions, suggest that collision frequency ν b/e E ∼ n e T −3/2 e can be considered as an important controlparameter of plasma dynamics.

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Section: Discussionmentioning

confidence: 99%

A Systematic Study of Impurity Ion Poloidal Rotation and Temperature Profiles Using CXRS in the TJ-II Stellarator

Carmona¹,

McCarthy²,

Tribaldos³

et al. 2008

Plasma and Fusion Research

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“…The device itself is very complex in design and construction, which is the main reason why development and implementation of stellarators is not very sought after. Experiments are still being carried out in Japan, at the Large Helical Device [7,8], and in Spain at the TJII [9,10]. The Wendelstein 7-X is currently being constructed in Germany.…”

Section: Nuclear Fusion and The Tokamak Reactormentioning

confidence: 99%

“…An ideal I-V curve for a Langmuir probe is presented in Figure 4.5. If V − V s kT e , then the probe current will be limited by the electron saturation current, given by 10) with n e , the electron density, A, the probe collection area and m e the electron mass.…”

Section: Density Measurementsmentioning

confidence: 99%

Repetitive operation of the University of Saskatchewan Compact Torus Injector

Pant

Hirose

Xiao

2010

Radiation Effects and Defects in Solids

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Development of fueling technologies for modern and future tokamak reactors is essential for their implementation in a commercial energy production setting. Compared to the presently available fueling technologies, gas or cryogenic pellet injection, compact torus injection presents an effective and efficient method for directly fueling the central core of tokamak plasmas. Fueling of the central core of a tokamak plasma is pivotal for providing efficient energy production. The central core plasma of a reactor contains the greatest density of fusion processes. For consistent and continuous fueling of tokamak fusion reactors, compact torus injectors must be operated in a repetitive mode.The goal of this thesis was to study the feasibility of firing the University of Saskatchewan Compact Torus Injector (USCTI) in a repetitive mode. In order to enable USCTI to fire repetitively, modifications were made to its electrical system, control system and data acquisition system. These consisted primarily of the addition of new power supplies, to enable fast charging of the many capacitor banks used to form and accelerate the plasma. The maximum firing rate achieved on USCTI was 0.33 Hz, an increase from the previous maximum firing rate of 0.2 Hz achieved at UC Davis.Firing USCTI in repetitive modes has been successful. It has been shown that the CTs produced in any given repetitive series are properly formed and repeatable. This is made evident through analysis of data collected from the CTs' magnetic fields and densities as they traveled along the injector barrel. The shots from each experiment were compared to the series' mean data and were shown to be consistent over time.Calculations of their correlations show that there are only minimal deviations from shot to shot in any given series.ii

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A compact flexible pellet injector for the TJ-II stellarator

McCarthy

Combs

Baylor

et al. 2008

Review of Scientific Instruments

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A compact pellet injector is being built for the TJ-II stellarator. It is an upgraded version of the "pellet injector in a suitcase" developed at Oak Ridge National Laboratory and installed on the Madison Symmetric Torus where it continues to be used in many plasma experiments. The design aim is to provide maximum flexibility at minimal cost, while allowing for future upgrades. It is a four-barrel system equipped with a cryogenic refrigerator for in situ hydrogen pellet formation, a combined mechanical punch/propellant valve system, pellet diagnostics, and an injection line, destined for use as an active diagnostic and for fueling. In order to fulfill both objectives it will be sufficiently flexible to permit pellets, with diameters from 0.4 to 1 mm, to be fabricated and accelerated to velocities from 150 to approximately 1000 m s(-1).

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The Design of an Electron Bernstein Wave Heating System for the TJ-II Stellarator

Cited by 7 publications

References 4 publications

A Systematic Study of Impurity Ion Poloidal Rotation and Temperature Profiles Using CXRS in the TJ-II Stellarator

A Systematic Study of Impurity Ion Poloidal Rotation and Temperature Profiles Using CXRS in the TJ-II Stellarator

Repetitive operation of the University of Saskatchewan Compact Torus Injector

A compact flexible pellet injector for the TJ-II stellarator

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