Temporal and spatial evolution of runaway electrons at the instability moments in Damavand tokamak

Abstract

The time and position behavior of runaway electrons at the Parail–Pogutse instability moments has been investigated using experimental observations in plasma current, loop voltage, the Hard X-ray (HXR) radiations, and 18 poloidal pickup coils signals received by data acquisition system simultaneously. The conditional average sampling (CAS) method was used to analyze the output data. Moreover, a filament current code was modified to study the runaway electrons beam movement in the event of instabilities. The results display a rapid drift of runaway beam toward the inner wall of the vacuum vessel and the collision with the wall components at the instability moments. The existence of the collisions in these experiments is evident in the HXR bursts which are considered as the main trigger for CAS Analysis. Also, the variation of HXR bursts with the toroidal magnetic field shows that the hard X-ray bursts drop with increase in the toroidal magnetic field and runaway electrons confinement quality.

Cherenkov radiation and cathodoluminescence in sapphire, quartz, and diamond under the excitation of an electron beam

“…They are used to detect runaway electrons and measure their parameters. [16][17][18][19][20][21][22][23][24][25][26][27] The use of CR in the detector of fast electrons can help to understand the physics of high-temperature plasma. As has been shown, the energy of runaway electrons in Tokamak systems can range from tens of kilo-to tens of mega-electron volts 28,29) and they can damage the walls of chamber.…”

О Влиянии Давления Воздуха На Параметры Тока Пучка И Рентгеновского Излучения, Генерируемых В Газовом Диоде

“…Благодаря короткой длительности тока пучка и достаточно высокой амплитуде в оптимальных условиях [11][12][13] пучки убегающих электронов стали использоваться для изучения свечения кристаллов [14][15][16]. Кроме того, в последние годы возникла необходимость диагностики параметров убегающих электронов в установках типа ТОКАМАК [17][18][19][20]. Эта задача весьма актуальна в связи с влиянием убегающих электронов на нагрев плазмы и локальным разрушением стенок рабочей камеры.…”

Generation and registration of runaway electron beams during the breakdown of highly overvoltaged gaps filled with dense gases

“…[3-10]). The issues relating to the generation of runaway electrons in tokamaks are intensively studied by scientific teams involved in the solution of the problem of realization of controlled thermonuclear fusion [11][12][13][14][15]. In addition, there are papers on the generation of runaway electrons at atmospheric discharges in nature [16][17][18][19][20].However, there is relatively little information on the parameters of runaway electron beams and breakdown stage under conditions of generation of runaway electrons in different gases at pressure more than atmospheric one.…”

“…[3-10]). The issues relating to the generation of runaway electrons in tokamaks are intensively studied by scientific teams involved in the solution of the problem of realization of controlled thermonuclear fusion [11][12][13][14][15]. In addition, there are papers on the generation of runaway electrons at atmospheric discharges in nature [16][17][18][19][20].…”