Pinaki Patra
@bkcc.ac.in
Assistant Professor
Brahmananda Keshab Chandra College
EDUCATION
B.Sc., M.Sc. and Ph.D in Physics.
RESEARCH, TEACHING, or OTHER INTERESTS
Mathematical Physics, Nuclear and High Energy Physics, Statistical and Nonlinear Physics, Applied Mathematics
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Pinaki Patra
Springer Science and Business Media LLC
Pinaki Patra
AIP Publishing
A charged harmonic oscillator in a magnetic field, Landau problems, and an oscillator in a noncommutative space share the same mathematical structure in their Hamiltonians. We have considered a two-dimensional anisotropic harmonic oscillator with arbitrarily time-dependent parameters (effective mass and frequencies), placed in an arbitrarily time-dependent magnetic field. A class of quadratic invariant operators (in the sense of Lewis and Riesenfeld) have been constructed. The invariant operators (Î) have been reduced to a simplified representative form by a linear canonical transformation [the group Sp(4,R)]. An orthonormal basis of the Hilbert space consisting of the eigenvectors of Î is obtained. In order to obtain the solutions of the time-dependent Schrödinger equation corresponding to the system, both the geometric and dynamical phase-factors are constructed. A generalized Peres–Horodecki separability criterion (Simon’s criterion) for the ground state corresponding to our system has been demonstrated.
Pinaki Patra
Springer Science and Business Media LLC
Pinaki Patra, Aditi Chowdhury, and Milan Jana
Springer Science and Business Media LLC
P Patra, J P Saha, and K Biswas
Springer Science and Business Media LLC
K Biswas, J P Saha, and P Patra
Springer Science and Business Media LLC
Kalpana Biswas, Jyoti Prasad Saha, and Pinaki Patra
Springer Science and Business Media LLC
A Rai, P N Potukuchi, P Patra, G K Chaudhari, S S K Sonti, J Karmakar, B Karmakar, A Sharma, D S Mathuria, A Pandey,et al.
IOP Publishing
Systematic studies have been performed on the effect of the surface processing techniques for improving accelerating gradients in superconducting niobium quarter wave resonators (QWR). These include high pressure rinsing (HPR), high temperature heat treatment of cavities and helium pulse processing. Tests done after HPR have not only shown a reduction in field emission in the cavities at high accelerating gradients but also an improvement in the low field quality factor (Q). The effect of the high temperature (650 °C) heat treatment of jacketed QWRs (QWR with the outer helium vessel) on the cavity gradients has also been investigated. This was performed for two different QWR designs and a substantial improvement in performance has been observed in both the cases. The increase in gradients is beyond that due to hydrogen degassing alone. Helium pulse processing during 4 K tests has been tried out on several cavities and its effect on the quality factor at both high and low gradients has been observed. This technique has been found to be useful for those resonators which have a high Q at lower fields but are limited due to the field emission at higher gradients. They have exhibited a marked improvement in the high field Q-slope over and above that obtained with conventional pulse processing under high vacuum. A comprehensive overview of all these developments carried out over the past few years has been reported.
S. Ghosh, V. Joshi, J. Urakawa, N. Terunuma, A. Aryshev, S. Fukuda, M. Fukuda, B.K. Sahu, P. Patra, S.R. Abhilash,et al.
Elsevier BV
Subhendu Ghosh, T. Rao, B. Sahu, B. Karmakar, S. Tripathi, Sunil Kumar, U. Lehnert, Arun Kumar Pandey, D. Kabiraj, S. Fukuda,et al.
The first phase of the pre-bunched Free Electron Laser (FEL) based on the RF electron gun, has been initiated at Inter University Accelerator Centre (IUAC), New Delhi. The photoinjector-based electron gun made from OFHC copper was fabricated and tested with low power RF. The beam optics calculation by using ASTRA and GPT codes are performed and radiation produced from the pre-bunched electron bunches are being calculated. The high-power RF system was ordered and will be commissioned at IUAC by the beginning of 2018. The design of the laser system is being finalised and assembly/testing of the complete laser system will be started soon in collaboration with KEK, Japan. The initial design of the photocathode deposition system has been completed and its procurement/de-velopment process is also started. The first version of the undulator magnet design is completed and its further im-provements are underway. The initial design of the DLS beam line have been worked out and various beam diag-nostics components are being finalised. Production
B.K. Sahu, R. Ahuja, Rajesh Kumar, S.K. Suman, D.S. Mathuria, A. Rai, P. Patra, A. Pandey, J. Karmakar, G.K. Chowdhury,et al.
Elsevier BV
P Patra and J P Saha
Springer Science and Business Media LLC
Pinaki Patra, Md. Raju, Gargi Manna, and Jyoti Prasad Saha
Hindawi Limited
The Ostrogradski approach for the Hamiltonian formalism of higher derivative theory is not satisfactory because the Lagrangian cannot be viewed as a function on the tangent bundle to coordinate manifold. In this paper, we have used an alternative approach which leads directly to the Lagrangian which, being a function on the tangent manifold, gives correct equation of motion; no new coordinate variables need to be added. This approach can be used directly to the singular (in Ostrogradski sense) Lagrangian. We have used this method for the Regge-Teitelboim (RT) minisuperspace cosmological model. We have obtained the Hamiltonian of the dynamical equation of the scale factor of RT model.
PINAKI PATRA, TANMAY MANDAL, and JYOTI PRASAD SAHA
Springer Science and Business Media LLC
Trina Chakraborty, Manik Banik, and Pinaki Patra
Springer Science and Business Media LLC
Biplab Pal, Pinaki Patra, Jyoti Prasad Saha, and Arunava Chakrabarti
American Physical Society (APS)
We present an exact analytical method of engineering the localization of electromagnetic waves in a fractal waveguide network. It is shown that, a countable infinity of localized electromagnetic modes with a multitude of localization lengths can exist in a Vicsek fractal geometry built with diamond shaped monomode waveguides as the 'unit cells'. The family of localized modes form clusters of increasing size. The length scale at which the onset of localization for each mode takes place can be engineered at will, following a well defined prescription developed within the framework of a real space renormalization group. The scheme leads to an exact evaluation of the wave vector for every such localized state, a task that is non-trivial, if not impossible for any random or deterministically disordered waveguide network.
PINAKI PATRA, ABHIJIT DUTTA, and JYOTI PRASAD Saha
Springer Science and Business Media LLC
T.S. Datta, S. Ghosh, J. Antony, S. Babu, J. Chacko, A. Choudhury, G.K. Choudhuri, D. Kanjilal, S. Kar, M. Kumar,et al.
Elsevier BV
S. Ghosh, R. Mehta, G. K. Chowdhury, A. Rai, P. Patra, B. K. Sahu, A. Pandey, D. S. Mathuria, J. Chacko, A. Chowdhury,et al.
American Physical Society (APS)
A superconducting linear accelerator based on niobium quarter wave resonators has recently become operational to boost the energy of the heavy ion beams available from the existing 15 UD (unit doubled) Pelletron accelerator. The niobium resonators typically performed at an accelerating field of $3\\char21{}6\\text{ }\\text{ }\\mathrm{MV}/\\mathrm{m}$ at 6 watts of input power in the test cryostat. When they were tested in the linac cryostat, the accelerating fields were drastically reduced and a number of other problems were also encountered. At present, all the problems have been diagnosed and solved. Many design modifications, e.g., in power coupler, mechanical tuner, helium cooling system, etc. were incorporated to solve the problems. A novel method of vibration damping was also implemented to reduce the effect of microphonics on the resonators. Finally, the accelerated beam through linac was delivered to conduct experiments.
S. Ghosh, P. N. Patra, B. K. Sahu, A. Rai, G. K. Chaudhari, A. Pandey, D. Kanjilal, and A. Roy
American Physical Society (APS)
The control of superconducting resonators requires a large amount of rf power due to their narrow bandwidth and the presence of microphonics in the ambience, although only a small part is dissipated inside the resonator to generate the accelerating field. A simple and innovative method has been devised to reduce the effect of microphonics on the quarter-wave resonators. Experiments have been conducted successfully at room temperature and at 4.2 K to demonstrate the effect of the new damping mechanism. A detailed report of the experiments with the superconducting resonators in a test cryostat and an on-line linac cryostat is presented in this paper.