In this experiment, the effect of magnetohydrodynamic (MHD) fluctuations in the hard X-ray radiation from the IR-T1 tokamak plasma is investigated. To reach this goal, the main parameters of plasma ...such as plasma current and loop voltage are measured. Also, the rake and poloidal Langmuir probes are used to calculate the radial and poloidal electric fields. To detect the hard X-ray radiation, a NaI-scintillator detector is used. To study on the MHD fluctuations, an array of 12 Mirnov coils is used. The obtained data are analyzed by using the singular value decomposition (SVD) algorithm. The wavelet spectrum of the dominant principal components of Mirnov coils is drawn. The results of wavelet and SVD analysis show that the hard X-ray radiation is increased with increasing the fluctuations of the dominant principal components (at the same time). It is also shown that the rate of hard X-ray radiation emitted from the tokamak plasma increased with increasing the MHD fluctuations. The energy of the system is wasted and reduced by these radiations. This an increase in the particle pressure of the plasma.
The boron-carbon structure is a highly used material in industry and the military. It can be made in different ways. In this research, boron-carbon structures were grown by a HFCVD device at ...different heater temperatures 600 °C, 650 °C, 700 °C, 750 °C and a carbon without B-doping for comparison. XRD analysis shows the boron carbide compounds corresponding to planes of (119) (006) and (018). Raman analysis illustrated peaks at 283-296 cm
− 1
which are related to the B
4
C structure. The grain size of structures was calculated using the Tuinstra–Koenig equation as 10.51-18.68 nm and their roughness was measured by AFM as 13.5-71 nm. Increasing the temperature increases the graphite plates, making them wider and thinner. Also, increasing the temperature increases the grain size and the roughness.
In this paper we have studied an Ergodic Magnetic Limiter (EML) based chaotic magnetic field for transport control in the edge plasma of IR-T1 tokamak. The resonance created by the EML causes ...perturbation of the equilibrium field line in tokamak and as a result, the field lines are chaotic in the vicinity of the dimerized island chains. Transport barriers are formed in the chaotic field line and actually observe in tokamak with reverse magnetic shear. We used area-preserving non-twist (and twist) Poincaré maps to describe the formation of transport barriers, which are actually features of Hamiltonian systems. This transport barrier is useful in reducing radial diffusion of the field line and thus improving the plasma confinement.
The toroidal magnetic field which is created by toroidal coils has the ripple in torus space. This magnetic field ripple has an importance in plasma equilibrium and stability studies in tokamak. In ...this paper, we present the investigation of the interaction between the toroidal magnetic field ripple and resonant helical field (RHF). We have estimated the amplitude of toroidal field ripples without and with RHF (with different q = m/n) ( m = 2, m = 3, m = 4, m = 5, m = 2 & 3, n = 1) using "Comsol Multiphysics" software. The simulations show that RHF has effects on the toroidal ripples.
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