Projects reports of M Sc course http://dspace.dtu.ac.in:8080/jspui/handle/repository/18356 2026-07-22T18:31:17Z 2026-07-22T18:31:17Z SAGAR, HIMANK Sharma, Suresh C (SUPERVISOR) Gupta, D.N. (CO-SUPERVISOR) http://dspace.dtu.ac.in:8080/jspui/handle/repository/23043 2026-07-16T05:14:16Z 2023-04-01T00:00:00Z

Title: TERAHERTZ FIELD EXCITATION FROM A PLASMA SLAB WITH LASER PULSE INTERACTION Authors: SAGAR, HIMANK; Sharma, Suresh C (SUPERVISOR); Gupta, D.N. (CO-SUPERVISOR) Abstract: We consider the excitation of terahertz (THz) radiation using the interaction of a Gaussian laser pulse with a plasma slab. Using the properties of the Gaussian laser pulse, the terahertz radiation is produced in the plasma slab. It is found that the ponderomotive force produced by the laser causes oscillations of the plasma electrons' velocity, and the ponderomotive potential of the laser generates the terahertz radiation in the plasma slab. The dependency of the field excited on the axial and radial dimensions of the plasma slab, as well as the duration and spot size of the laser pulse, is considered. We have found that the amplitude of the excited field increases four times for a highly focused laser pulse. It is found that the excitation of the terahertz radial fields is most effective in the case of the generation frequency close to the plasma frequency and when the duration of the laser pulse is about the same as the axial dimension of the plasma slab.

2023-04-01T00:00:00Z AMAN Chaujar, Rishu (SUPERVISOR) http://dspace.dtu.ac.in:8080/jspui/handle/repository/23030 2026-07-08T04:47:47Z 2026-05-01T00:00:00Z

Title: TCAD-BASED MAGNETIC ANALYSIS OF 2D-MagFinFET IN ORTHOGONAL DIRECTIONS FOR MEDICAL MICR0-ROBOTS APPLICATION Authors: AMAN; Chaujar, Rishu (SUPERVISOR) Abstract: The need for magnetic sensor is aggressively increasing in medical area to navigate the medical micro-robots through the blood vessels to target. This dissertation presents a detailed TCAD based investigation of novel Two Directional Magnetic Fin Field Effect Transistor (2D-MagFinFET) magnetic sensor based on the advanced 3D architecture of Field Effect Transistor. The proposed device is designed to overcome the limitation of traditional magnetic sensor to only sense the single direction magnetic field. The proposed device is designed to sense orthogonal magnetic field in Y and Z direction. It is operated on concept of Lorentz force act on charge carrier in channel when external magnetic field applied which deflect the carrier from their path which governs differential current (∆ID). Device uses two parallel fins to sense the magnetic field. One fin will detect the magnetic field of Y-direction and other one of Z-direction without any coupling of relative sensitivity. Two layers of SiO2/HfO2 as gate dielectric is used to enhance the overall performance of the proposed device. The performance of the proposed device is analyzed in terms of SS, VTH, ION, IOFF, DIBL, SR, magnetic sensitivity (SA) and Relative magnetic sensitivity (SR). The proposed device demonstrates a SS of 59.96 mV/dec which is improved by 4.83% in contrast to existing devices. The VTH of device is increased from 0.21 V to 0.48 V by 128.57% which help to protect the sensor to turn on accidently. IOFF and ION currents of the proposed device is 5.24 fA and 12.9 µA having SR of 2.39 × 109. The proposed device has a DIBL of 8.24 mV/V at gate length of 50 nm show how efficiently device overcome the problem of short channel effect. These results demonstrate the better switching and performance of proposed device than the existing device. The magnetic response shows the linear dependency of differential current (∆IY and ∆IZ) with Magnetic field having a sensitivity of 159.27 nA/T in Y-direction and 147.13 nA/T in Z-direction at 100 µA biased current. The relative sensitivity is 0.00159 T-1 and 0.00147 T-1 in Y and Z direction respectively, improved from recently reported device. Owing the magnetic sensitivity in orthogonal direction the proposed device is suitable for the spatial tracking and navigation of medical micro-robots.

2026-05-01T00:00:00Z SINHA, ANCHIT Sharma, Suresh C. (SUPERVISOR) http://dspace.dtu.ac.in:8080/jspui/handle/repository/22958 2026-07-02T05:24:42Z 2026-05-01T00:00:00Z

Title: ANALYSIS OF SELF-FOCUSING OF LASER BEAMS IN QUANTUM PLASMA Authors: SINHA, ANCHIT; Sharma, Suresh C. (SUPERVISOR) Abstract: The relativistic self-focusing of laser beams in quantum plasma has drawn considerable inter est because of its applications in inertial confinement fusion, charged-particle acceleration, and high-energy-density physics. In this dissertation, we study the propagation and self-focusing of non-conventional beam profiles, namely Bessel-Gaussian and Elliptical-Gaussian beams, in magnetized quantum plasmas with spatial density gradients. The paper considers combinations of beam geometry, magnetic fields and plasma inhomogeneity which have never been system atically treated in previous work. The study uses the quantum hydrodynamic (QHD) model, incorporating the Bohm potential, exchange-correlation effects, relativistic ponderomotive forces, and the influence of an exter nal magnetic field. Applying the paraxial approximation and the Wentzel–Kramers–Brillouin (WKB) method reduces Maxwell’s equations to a differential equation governing beam-width evolution along the propagation axis. For Paper-1 on Bessel-Gaussian beams, this results in a second-order nonlinear ordinary differential equation, solved numerically using the fourth-order Runge-Kutta method. Simulations are carried out for high laser frequencies of (1.78×1020s−1), electron densities of (n0 = 4 × 1019cm−3) satisfying (χ ≥ 1), an axial magnetic field of (ωc/ω = 0.3), and exponential density ramp parameters (d = 5,10,20). Key findings from Paper-1 show that: (1) thermal quantum plasma enables much stronger and more sustained self-focusing than classical and cold quantum plasmas; (2) exponential den sity ramps greatly accelerate self-focusing, maintaining high intensity over multiple Rayleigh lengths; (3) Bessel-Gaussian beams outperform Gaussian beamsbecauseoftheirring-shaped in tensity profile; (4) the transverse wave parameter µ significantly enhances self-focusing; and (5) beyond a threshold, increasing laser intensity reduces self-focusing due to relativistic mass satu ration and exchange-correlation effects introducing competingnonlinearities. Paper-2(Elliptical Gaussian beams in magnetized quantum plasma with tangential densityramps)isinanadvanced stage with mathematical framework and numerical analysis under way.

2026-05-01T00:00:00Z AMISHI Bohidar, Himadri B (SUPERVISOR) http://dspace.dtu.ac.in:8080/jspui/handle/repository/22954 2026-06-30T04:31:45Z 2026-05-01T00:00:00Z

Title: KINECTICS OF PROTEIN- AGGREGATION AND SELF ASSEMBLY Authors: AMISHI; Bohidar, Himadri B (SUPERVISOR) Abstract: The process of protein aggregation is a vital one which depends on time and necessitates models which transcend closed-system approaches to become models of dynamic kinetics and proteostasis. The generalized modelling approach connects the physical mechanism of aggregation with the biological system of aging. This physical model is composed of kinetic laws, the behaviours of the source terms (monomer generation/elimination), and thermos- reversible assembly. The model predicts the scaling behaviours of aggregation which depend on whether the process is limited by the formation of aggregates or the generation of monomers. The biological aspect of the modelling framework takes into account the effect of the decline in the process of proteostasis in a systems biology model. Coupled differential equations form the basis of this biological model with consideration of the decline in physiological function, hormone regulation, genetic instability, and gender-related effects. Importantly, the non-linear dynamics of proteostasis with respect to age-related stresses and inefficient clearing must be accounted for since they can lead to a tipping point where a rapid build-up occurs.

2026-05-01T00:00:00Z