A novel scheme of injection and confinement of electrons is reported for the formation of a toroidal electron cloud in the presence of a static toroidal magnetic field. The scheme is based on the use of a combination of externally applied electric field and the self-consistent space charge field for the electron trapping and confinement. The time development of electron cloud potentials measured in the poloidal plane of the torus is presented. A potential well depth exceeding the initial kinetic energy of the electrons is observed, indicating collective effects. The effect of external field on the total charge and capacitance of the electron cloud is also presented.

The Yamuna river has become one of the most polluted rivers in India as well as in the world because of the high-density population growth and speedy industrialization. The Yamuna river is severely polluted and needs urgent revival. The Yamuna river in Dehradun is polluted due to exceptional tourist activity, poor sewage facilities, and insufficient wastewater management amenities. The measurement of the quality can be done by water quality assessment. In this study, the water quality index has been calculated for the Yamuna river at Dehradun using monthly measurements of 12 physicochemical parameters. Trend forecasting for river water pollution has been performed using different parameters for the years 2020–2024 at Dehradun. The study shows that the values of four parameters namely, Temperature, Total Coliform, TDS, and Hardness are increasing yearly, whereas the values of pH and DO are not rising heavily. The considered physicochemical parameters for the study are TDS, Chlorides, Alkalinity, DO, Temperature, COD, BOD, pH, Magnesium, Hardness, Total Coliform, and Calcium. As per the results and trend analysis, the value of total coliform, temperature, and hardness are rising year by year, which is a matter of concern. The values of the considered physicochemical parameters have been monitored using various monitoring stations installed by the Central Pollution Control Board (CPCB), India.

No abstract

No abstract

Several present day Tokamak experiments have reported large plasma rotations (of the order of round snced) induced hy nwtralhram injectinn during auxilisry hcilting Thc m~ilsiir~d ro!a!io~ pmfiles indicatethat velocityshearcan be significant. Wcenamine theeffect ofsuchsheared Rowson thcequilibrium of Tokamak plasmas. Using the generalized MHD equilibrium equations for axisymmetric rotation and adopting a variational formulation, we carry out a detailed numerical investigation of the farm of the magnetic surfaces and other equilibrium qnantitics as a function of the Row function profile. In certain limits we also obtain analytic exprcssions for the ellipticity and finite shift ofthe magnetic axis.