PT-symmetric Solutions of Schrodinger Equation with position-dependent mass via Point Canonical Transformation

PT-symmetric solutions of Schrodinger equation are obtained for the Scarf and generalized harmonic oscillator potentials with the position-dependent mass. A general point canonical transformation is applied by using a free parameter. Three different forms of mass distributions are used. A set of the energy eigenvalues of the bound states and corresponding wave functions for target potentials are obtained as a function of the free parameter.Comment: 13 page

Effect of 50 MeV Li3+ ion irradiation on electrical characteristics of high speed NPN power transistor

Silicon NPN overlay RF power high speed commercial bipolar junction transistors (BJTs) find applications in military, space and communication equipments. Here we report the effect of 50 MeV Li3+ ion irradiation in the fluence range 1 à 1011-1.8 à 1012 ions cm-2 on NPN power transistor. The range (R), electronic energy loss (Se), nuclear energy loss (Sn), total ionizing dose (TID) and total displacement damage (Dd) in the silicon target are calculated from TRIM Monte Carlo Code. Output resistance is 3.568 à 104 Ω for unirradiated device and it increases to 6 à 107 Ω as the fluence is increased from 1 à 1011 to 1.8 à 1012 ions cm-2. The capacitance of the emitter-base junction of the transistor decreases and dielectric loss of the emitter-base junction increases with increase in ion fluence. The built in voltage of the unirradiated sample is 0.5 V and it shifts to 0.4 V after irradiation at fluence of 1.8 à 1012 ions cm-2 and the corresponding doping density reduced to 5.758 à 1016 cm-3. The charge carrier removal rate varies linearly with the increase in ion fluence. © 2008

Magnetic Tuning and Installation Modifications of U48 Undulator for the Delhi Light Source DLS

A compact THz radiation facility based on the principle of a pre bunched Free Electron Laser, called Delhi Light Source DLS is at the final stage of commissioning at IUAC, New Delhi, India. For generation of THz radiation in DLS, an undulator with period length of 48 mm U48 , built by HZB and refurbished at DESY will be used. The magnetic tuning and the field measurements have been done on the U48 along with the design and installation of correction coils at the entrance exit of the U48. In addition, horizontal and vertical ambient field correction coils were integrated into the magnet girders. A quadrupole correction coil along the vacuum chamber in order to mitigate the defocusing effect of the U48 on the electron beam has been designed. The current through all coils has been adjusted as a function of the gap by the new control system designed for the U48. In addition, an extruded aluminium vacuum chamber was designed and fabricated and will be aligned with the the undulator soo