Movable limiter experiment on tpe-1rm15 reversed field pinch machine

Yagi, Y.; Shimada, Takahiro; Hirota, Isao; Maejima, Y.; Hirano, Y.; Ogawa, Kiyoshi; Namiki, K.; Ioki, K.

doi:10.1016/0022-3115(89)90351-6

Cited by 22 publications

(7 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has to be mentioned that in RFPs the footprint of PWI also shows a poloidal asymmetry between ion and electron drifts, with electron and ion flows separately intercepted by the wall, due to the surface distortion [366,367,577,578]. An example is shown in figure 68.…”

Section: Effect Of Magnetic Topology On Plasma-wall Interactionmentioning

confidence: 99%

The reversed field pinch

et al. 2021

View full text Add to dashboard Cite

This paper reviews the research on the reversed field pinch (RFP) in the last three decades. Substantial experimental and theoretical progress and transformational changes have been achieved since the last review (Bodin 1990 Nucl. Fusion 30 1717–37). The experiments have been performed in devices with different sizes and capabilities. The largest are RFX-mod in Padova (Italy) and MST in Madison (USA). The experimental community includes also EXTRAP-T2R in Sweden, RELAX in Japan and KTX in China. Impressive improvements in the performance are the result of exploration of two lines: the high current operation (up to 2 MA) with the spontaneous occurrence of helical equilibria with good magnetic flux surfaces and the active control of the current profile. A crucial ingredient for the advancements obtained in the experiments has been the development of state-of-art active feedback control systems allowing the control of MHD instabilities in presence of a thin shell. The balance between achievements and still open issues leads us to the conclusion that the RFP can be a valuable and diverse contributor in the quest for fusion electricity.

show abstract

Section: Effect Of Magnetic Topology On Plasma-wall Interactionmentioning

confidence: 99%

The reversed field pinch

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The presence of an energetic component in the electron velocity distribution is generally observed in the edge of reversed-field pinch (RFP) experiments. Such observations are based on heat flux measurements [1][2][3][4][5][6][7][8][9], measurements using an electron energy analyser (EEA) [10][11][12][13] or by viewing the x-rays from a target which is inserted into the plasma [14][15][16]. The source of the energetic electrons in the edge region is believed to be associated with stochastic radial transport from the hot central region caused by fluctuations (b r ) of the radial component of the field relative to the equilibrium field [17].…”

Section: Introductionmentioning

confidence: 99%

Measurements of hot electrons in the Extrap T1 reversed-field pinch

Welander

Bergsåker

1998

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

The presence of an anisotropic energetic electron population in the edge region is a characteristic feature of reversed-field pinch (RFP) plasmas. In the Extrap T1 RFP, the anisotropic, parallel heat flux in the edge region measured by calorimetry was typically several hundred MW m −2 . To gain more insight into the origin of the hot electron component and to achieve time resolution of the hot electron flow during the discharge, a target probe with a soft x-ray monitor was designed, calibrated and implemented. The x-ray emission from the target was measured with a surface barrier detector covered with a set of different x-ray filters to achieve energy resolution. A calibration in the range 0.5-2 keV electron energy was performed on the same target and detector assembly using a LaB 6 cathode electron gun. The calibration data are interpolated and extrapolated numerically. A directional asymmetry of more than a factor of 100 for the higher energy electrons is observed. The hot electrons are estimated to constitute 10% of the total electron density at the edge and their energy distribution is approximated by a half-Maxwellian with a temperature slightly higher than the central electron temperature. Scalings with plasma current, as well as correlations with local Hα measurements and radial dependences, are presented.

show abstract

“…In particular on the side facing the electron drift direction the thermal load is of the order of 300 MWm -z at r = 12.5 cm [11] and almost an order of magnitude lower on the ion drift side. The high thermal load on the electron drift side can be interpreted, according to the results found in other experiments [5,8,9], as due to a small fraction of energetic electrons travelling from the hotter central region of the plasma to the wall without undergoing collisions [16,18].…”

Section: (Ricevuto Il 3 Maggio 1990)mentioning

confidence: 95%

Investigation of the ETA-BETA II plasma edge by surface analysis of collector probes

et al. 1991

View full text Add to dashboard Cite

Summary. --To investigate the ion flux escaping from the plasma and the impurity flux released by the wall, collector probes made of graphite, silicon and titanium have been exposed to the deuterium plasma confined in the toroidal device ETA BETA II. The damages on the collector surfaces have been surveyed by a scanning electron microscopy (SEM) apparatus. The deuterium and impurity retention have been measured by elastic recoil detection (ERD) and Rutherford backscattering spectroscopy (RBS) techniques respectively. The implantation build-up has been investigated as a function of the exposure time. The deuterium dose in graphite saturates after a few discharges, whereas the metal impurities exhibit a linear increase in time. The deuterium flux and its radial dependence, inferred from the implanted concentrations, have been compared with those measured by Langmuir probes. Metal impurities have been identified and their relative abundances have been compared with the material wall composition. The impurity flux is found consistent with the global content in the plasma derived by spectroscopic measurements. The deuterium dose measured in different samples has been related to the backscattering coefficient of the materials. Finally, to investigate the damage on sample probes facing the plasma particle flow, erosion probes made of vitreous graphite with silver implanted at a fixed depth have been exposed to the plasma and the thickness change after exposure recovered.PACS 85.40 -Integrated electronics; VLSI. PACS 52.40 -Plasma interactions. PACS 52.70 -Plasma diagnostic techniques and instrumentation. 435

show abstract

Movable limiter experiment on tpe-1rm15 reversed field pinch machine

Cited by 22 publications

References 3 publications

The reversed field pinch

The reversed field pinch

Measurements of hot electrons in the Extrap T1 reversed-field pinch

Investigation of the ETA-BETA II plasma edge by surface analysis of collector probes

Contact Info

Product

Resources

About