1.4 The existence of DPs in nature and laboratory

DPs are found in the ionosphere, that's a lower part of the earth. Noctilucent clouds (NLs) are composed of ice and dust from manmade pollution and heavy clusters. In the space environment, the examples of dusty (complex) plasma are Jupiter rings, were first observed in 1779, comets, planetary rings and spokes, Saturn's rings and Neptune. The size of dust particles in Saturn ring varies from micron to sub-micron. The radial spokes also consist of micron and submicron sized dust charged particles that are electrostatically levitated. The presence of dust particles in the atmosphere at the altitudes in the range of 80 and 90 km was observed during polar summer mesopause [20]. The presence of dust particles was observed in the nuclear fusion devices, both Tokamaks and stellarators. Due to the presence of dust particles in these devices may disturb the performance and stop working on it. Nowadays, study of dust particles in fusion devices becomes very important. The charging mechanisms of dust particles in these devices are also investigated by Liu et al. [21]. It becomes very necessary for operational Tokamak or other fusion devices to study and found waves and transport properties of dusty plasma. Thermal conductivity, diffusion coefficient, shear viscosity in dusty plasma and charging mechanisms of dust particles in nuclear fusion devices are also needed to investigate [22]. The dust particles are also observed in radio frequency (RF) device and direct current (DC) glow discharge tube and Z-Pinch device etc. Under the laboratory condition, the plasma crystals are observed in different devices such as in RF, DC, thermal plasma, nuclear-induced dusty plasma over wide range of plasma parameters [23].

### 1.5 Nuclear fusion devices

Fusion energy is a source of energy for a future generation which is almost inexhaustible. Currently, it is an undefeatable challenge for engineering and

thermophysical researchers. The basic challenge to achieve the fusion energy is "to achieve a rate of heat emitted by fusion plasma that exceeds the rate of energy injected into the plasma". The central expectations are focused on two fusion reactor devices, one is Tokamak and the other is stellarator. Today the whole world community is working for nuclear fusion device, which is known as Tokamak. Fusion energy is investigated and comes closest to the explosion. These devices consist of a ring-type magnetic field used to confine the plasma. Tokamak plasma is confined by an electric current flowing in plasma, and in the stellarators, a magnetic field of very complicated shape used to confine plasma stationary. The Tokamak work only in the pulsed mode without auxiliary facilities and stellarators is suitable for continuous operation. The most effective magnetic field configuration is toroidal in the shape of the doughnut. The Tokamaks, stellarators and the reversed field pinch (RFP) are commonly under developing fusion nuclear devices based on toroidal confinement configuration. The Z-pinch is also nuclear fusion device in which is a strong electrical current in plasma to generate X-rays. The magnetized target fusion, referred to as a MIF (magneto-inertial fusion) system, is also currently in progress. In these nuclear devices, a magnetic field is applied to confine the plasma with the help of electromagnetic or mechanical linear implosion. A compression heating is provided with laser hot dense magnetized plasma which is created in the plasma focus (PF) devices. The PF devices belong to the family of dynamic noncylindrical Z-pinch. If in this device deuterium is used as gases then DD fusion reaction takes place [24–28].
