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Singh U.,Indian Central Electronics Engineering Research Institute | Bera A.,Indian Central Electronics Engineering Research Institute | Kumar N.,Indian Central Electronics Engineering Research Institute | Purohit L.P.,Gurukul Kangri Vishwavidyalaya | Sinha A.K.,Indian Central Electronics Engineering Research Institute
Journal of Infrared, Millimeter, and Terahertz Waves | Year: 2010

A triode type magnetron injection gun (MIG) of a 42 GHz, 200 kW gyrotron for an Indian TOKAMAK system is designed by using the commercially available code EGUN. The operating voltages of the modulating anode and the accelerating anode are 29 kVand 65 kV respectively. The operating mode of the gyrotron is TE 03 and it is operated in fundamental harmonic. The simulated results of MIG obtained with the EGUN code are validated with another trajectory code TRAK. © Springer Science+Business Media, LLC 2010. Source


Kumar A.,Gurukul Kangri Vishwavidyalaya
Pramana - Journal of Physics | Year: 2014

In the present paper, a temperature-dependent equation of state (EOS) of solids is discussed which is found to be applicable in high-pressure and high-temperature range. Present equation of state has been applied in 18 solids. The calculated data are found in very good agreement with the data available from other sources. © Indian Academy of Sciences. Source


Singh U.,Indian Central Electronics Engineering Research Institute | Kumar N.,Indian Central Electronics Engineering Research Institute | Tandon S.,Indian Central Electronics Engineering Research Institute | Khatun H.,Indian Central Electronics Engineering Research Institute | And 2 more authors.
Progress In Electromagnetics Research Letters | Year: 2010

A 40A triode-type magnetron injection gun for a 1MW, 120 GHz gyrotron has been designed. The preliminary design has been obtained by using some trade-off equations. Computer simulation has been performed by using the commercially available code EGUN and the in-house developed code MIGANS. The operating voltages of the modulating anode and the accelerating anode are 60 kV and 80 kV, respectively. The electron beam with a low transverse velocity spread (δβ{box drawings light up and horizontal}= 3:3%) and velocity ratio, α = 1:38 at beam current = 40A is obtained. The simulated results of the MIG obtained with the EGUN code have been validated with another trajectory code TRAK. The results on the design output parameters obtained by these two codes were found to be in close agreement. The sensitivity study has been carried out by changing the different gun parameters to decide the fabrication tolerance. Source


Uniyal R.,Gurukul Kangri Vishwavidyalaya | Chandrachani Devi N.,Observatorio Nacional | Nandan H.,Gurukul Kangri Vishwavidyalaya | Purohit K.D.,Hemwati Nandan Bahuguna Garhwal University
General Relativity and Gravitation | Year: 2015

We study the time-like geodesic congruences, in the space-time geometry of a Schwarzschild black hole surrounded by quintessence. The nature of effective potential along with the structure of the possible orbits for test particles in view of the different values of quintessence parameter are analysed in detail. An increase in quintessence parameter is seen to set the particles from further distance into motion around black hole. The effect of quintessence parameter is investigated analytically wherever possible otherwise we perform the numerical analysis to probe the structure of possible orbits. It is observed that there exist a number of different possible orbits for a test particle in case of non-radial geodesics, such as circular (stable as well as unstable) bound orbits, radially plunge and fly-by orbits, whereas no bound orbits exist in case of radial geodesics. © 2015, Springer Science+Business Media New York. Source


Uniyal R.,Gurukul Kangri Vishwavidyalaya | Nandan H.,Gurukul Kangri Vishwavidyalaya | Biswas A.,Ranaghat College | Purohit K.D.,Hemwati Nandan Bahuguna Garhwal University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

We study the geodesic motion of massive and massless test particles in the background of a particular class of multiple charge black holes in gauged supergravity theories in D=4. We have analyzed the horizon structure along with the nature of the effective potentials for the case of four equal charges. In view of the corresponding effective potentials, we have discussed all the possible orbits in detail for different values of energy and angular momentum of the incoming test particles. The periods for one complete revolution of circular orbits and the advance of perihelion of the planetary orbit have also been investigated in greater detail for massive test particles. We have also discussed the time period of unstable circular motion and cone of avoidance of massless test particles in detail. All the corresponding results obtained for massive and massless test particles are then compared accordingly. © 2015 American Physical Society. Source

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