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21.
In this paper we report a new geometry for diode laser pumping. We show that an efficient moving-disc laser can be designed which can operate at 20 kW of average power with existing diode laser technology. 相似文献
22.
A. S. Ghosh P. S. Mazumdar Madhumita Basu 《Zeitschrift für Physik A Hadrons and Nuclei》1984,319(1):13-16
The total ionization cross section in electron-hydrogen scattering in the energy range 20.4–68.0 eV has been calculated by a method in which the initial state of the system is treated by a distorted wave polarized orbital method and the final state is described by (1) a product of two unscreened Coulomb functions and (2) a product of a plane wave and a Coulomb function. The corresponding two sets of results using a plane wave in the incident channel have also been reported. The present results where both the electrons are represented by Coulomb waves are in closer agreement than other theoretical predictions With measured values. 相似文献
23.
Using a spot size based optimization technique, a bend loss versus dispersion diagram has been obtained theoretically for the most widely used step-index disper sion compensated optical fibers (DCF). The Rayleigh scattering loss can be incorpo rated with bend loss to calculate figure of merit (FOM), thus giving an FOM versus dispersion curve on a single diagram. The plot of the FOM-dispersion curve on a single diagram is useful from the designer's point of view, as it provides a quick reference for choosing the best suitable DCF, which should have large negative dispersion as well as maximum possible value of FOM. The effect of fiber manufac turing losses such as absorption loss on the maximum value of FOM has also been estimated. 相似文献
24.
25.
Mandira Sinha H. Majumdar P. Basu Subinit Roy R. Bhattacharya M. Biswas M. K. Pradhan R. Palit I. Mazumdar S. Kailas 《The European Physical Journal A - Hadrons and Nuclei》2010,44(3):403-410
Fusion excitation functions are measured for the system 6Li + 28Si using the characteristic $ \gamma$ -ray method, encompassing both the sub-barrier and above-barrier regions, viz, E lab = 7-24 MeV. Two separate experiments were performed, one for the above-barrier region ( E lab = 11-24 MeV) and another for the below-barrier region ( E lab = 7-10 MeV). The results were compared with our previously measured fusion cross-section for the 7Li + 28Si system. We observed the enhancement of the fusion cross-section at sub-barrier regions for both 6Li and 7Li , but the yield was substantially larger for 6Li . However, for well-above-barrier regions, a similar type of suppression was identified for both the systems. 相似文献
26.
The parabolic similariton pulse formation by alternate arrangements of passive and active dispersion compensating fibers (DCFs) is presented here. These combinations of passive and active DCFs with constant core radii and constant nonlinearities are suggested as equivalent profiles of a dispersion tailored fiber amplifier in normal dispersion regime. The dispersion tailored fibers, usually known as dispersion decreasing fibers (DDFs) in normal dispersion regime, are capable of producing linearly chirped parabolic self-similar pulses. The DDF is designed and optimized with proper choice of fiber parameters so that considerable variation of nonlinearity can be achieved, which in turn enhances the effective gain coefficient of the fiber. Inclusion of this nonlinear variation along the DDF amplifier length leads to obtain the simulated output pulses with very small misfit parameters with respect to perfect parabolic pulse at sufficiently reduced optimum length. At the same time to avoid the fabrication difficulties of the DDF, the alternately arranged passive and active DCFs are suggested as suitable alternatives of the DDF. The performances of the cascaded systems for generation of self-similar parabolic pulses are compared with that of the DDF amplifier as well as combined systems consisting of DCFs with equal gain. The results show that the proposed alternately arranged cascaded system with less pumping requirements, are efficient enough to produce similar parabolic pulses as compared to the previously designed DDF, even when considerable amount of splice loss at each joint is included. 相似文献
27.
The Zipf’s law is studied here in the context of size distribution of Indian cities and the power law exponent is estimated.
We have used the data from the Indian censuses of 1981,1991 and 2001. The analysis shows that the population distribution
in Indian cities do follow a power law similar to the ones found in other countries. The scaling exponent are found to be
2.15 ± 0.01 for 1981, 2.11 ± 0.01 for 1991 and 2.05 ± 0.02 for 2001 from the linear fit. We have also estimated the scaling
exponent from the maximum likelihood estimator technique which is found to be 2.04 ±.07 for the year 2001. 相似文献
28.
Asmita Mukherjee R. Basu H. Dahiya L. Gamberg R. Godbole S. Gupta M. C. Kumar L. Magnea P. Mathews N. Mathur A. Mukherjee P. J. Mulders V. Ravindran A. Tripathi 《Pramana》2009,72(1):277-283
This is the report of the QCD working sub-group at the Tenth Workshop on High Energy Physics Phenomenology (WHEPP-X).
相似文献
29.
A model forN-N interaction proposed earlier by two of us (VSB and VKG), has been extended to incorporate the tensor component of the nuclear
force. Based on the quark compound bag model (QCB), the nucleon-nucleon potential has a short range repulsive core which is
non-local and has a characteristic energy dependence and is expressed in terms of the parameters relating to the six-quark
compound bag. To account for the low energy properties, this repulsive core interaction is supplemented by a phenomenological
non-local potential containing both central (S-wave) and tensor components and operates only outside the QCB. Using this model, we analyse and compare the results with
the experimental data for the electromagnetic form factors of the deuteron, theD-state observables, such as the quadrupole moment, theD-state probability, and theD/S ratio along with then-p scattering phase shifts up to about 400 MeV. 相似文献
30.
Raj Gandhi Kamales Kar S. Uma Sankar Abhijit Bandyopadhyay Rahul Basu Pijushpani Bhattacharjee Biswajoy Brahmachari Debrupa Chakraborti M. Chaudhury J. Chaudhury Sandhya Choubey E. J. Chun Atri Desmukhya Anindya Datta Gautam Dutta Sukanta Dutta Anjan Giri Sourendu Gupta Srubabati Goswami Namit Mahajan H. S. Mani A. Mukherjee Biswarup Mukhopadhyaya S. N. Nayak M. Randhawa Subhendu Rakshit Asim K. Ray Amitava Raychaudhuri D. P. Roy Probir Roy Suryadeep Roy Shiv Sethi G. Sigl Arunansu Sil N. Nimai Singh Mark Vagins Urjit Yagnik 《Pramana》2003,60(2):405-409
This is the report of neutrino and astroparticle physics working group at WHEPP-7. Discussions and work on CP violation in
long baseline neutrino experiments, ultra high energy neutrinos, supernova neutrinos and water Cerenkov detectors are discussed. 相似文献