Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 8 of 8
Full-Text Articles in Physics
Anyonic Superconductivity In A Modified Large-U Hubbard Model, Asim Gangopadhyaya, Prasanta Panigrahi
Anyonic Superconductivity In A Modified Large-U Hubbard Model, Asim Gangopadhyaya, Prasanta Panigrahi
Asim Gangopadhyaya
A modified large-U Hubbard model at half filling is analyzed by a mean-field approach. Preserving a local U(1) symmetry of the action, the fluctuations about half filling are studied in the spirit of the commensurate-flux-phase condition. The fluctuations then contribute a Chern-Simons term to the tree-level Lagrangian with a coefficient appropriate to that of a half fermion. With the Coulomb repulsion term, we study the low-energy excitations of the model and show the existence of superconductivity in the presence of a four-Fermi interaction term.
Preliminary Results Of Is Plasma Focus As A Breeder Of Short-Lived Radioisotopes 12c(D,N)13n, S.M. Kiai, . ., Ahmad Talaei, Et Al.
Preliminary Results Of Is Plasma Focus As A Breeder Of Short-Lived Radioisotopes 12c(D,N)13n, S.M. Kiai, . ., Ahmad Talaei, Et Al.
Ahmad Talaei
Modified IS (Iranian Sun) plasma focus (10 kJ,15 kV, 94 μF, 0.1 Hz) has been used to produce the short-lived radioisotope 13N (half-life of 9.97 min) through 12C(d,n)13N nuclear reaction. The filling gas was 1.5–3 torr of hydrogen (60%) deuterium (40%) mixture. The target was solid nuclear grade graphite with 5 mm thick, 9 cm width and 13 in length. The activations of the exogenous target on average of 20 shots (only one-third acceptable) through 10–13 kV produced the 511 keV gamma rays. Another peak found at the 570 keV gamma of which both was measured by a NaI portable …
Theoretical Study Of The Endogenous Production Of N-13 In 115 Kj Plasma Focus Device Using Methane Gas, Saeedeh Haghani, A. Sadighzadeh, Ahmad Talaei, A. Zeem, S.M. Kiai, A. Heydarnia, V. Damideh
Theoretical Study Of The Endogenous Production Of N-13 In 115 Kj Plasma Focus Device Using Methane Gas, Saeedeh Haghani, A. Sadighzadeh, Ahmad Talaei, A. Zeem, S.M. Kiai, A. Heydarnia, V. Damideh
Ahmad Talaei
Mather type plasma focus device with the bank energy of 115 kJ (40 kV, 144μF) was studied for induced activity of N-13; a short-lived radioisotope β+ emitter with 511 keV of gamma rays and has a half-life of t1/2 = 9.93 min through 12C (d, n)13N nuclear reaction. N-13 radioisotope is used in Positron Emission Tomography (PET) for imaging and treatment. In this paper endogenous production of 13N is considered. It is shown by adding 3–4 % CH4 to the chamber, the induced activity of N-13 has increased about 4 %. Our study is representative of producing 106 − 109 …
Development Of Practical Method Using A Monte Carlo Code For Evaluation Of Optimum Fuel Pitch In A Typical Vver-1000 Core, Navid Taheranpoura, Ahmad Talaei
Development Of Practical Method Using A Monte Carlo Code For Evaluation Of Optimum Fuel Pitch In A Typical Vver-1000 Core, Navid Taheranpoura, Ahmad Talaei
Ahmad Talaei
In this work, we developed a practical method to evaluate the optimum moderator-to-fuel ratio of a typical VVER reactor using a Monte Carlo code. To reach this aim, by analyzing the curves of the infinite multiplication factor (k∞) versus moderator-to-fuel ratio, the optimum fuel pitch is determined for different fuel diameters of the proposed fuel elements using the MCNPX code. Optimum moderator-to-fuel ratio and fuel pitch were determined from the curves where the value of k∞ is maximum for cold conditions and is located in an under-moderated region for hot conditions. Also, the void reactivity coefficient …
Polarimetry Studies For The Npdgamma Experiment At The Sns, Jonny Dadras
Polarimetry Studies For The Npdgamma Experiment At The Sns, Jonny Dadras
Jonny Dadras
The NPDGamma collaboration aims to measure a parity-violating directional gamma-ray asymmetry from the capture of polarized cold neutrons on protons. The asymmetry, predicted to be on the order of 50 ppb, is a result of the weak interaction between mesons and nucleons during the neutron capture reaction. The experiment is designed to make a statistics limited measurement of the asymmetry at the level of about 20%. The experiment will be carried out at the Fundamental neutron Physics Beamline (FnPB) at the Spallation Neutron Source (SNS). The neutron beam is polarized by a super-mirror polarizer. A 9.5 G magnetic field guides …
Quark-Antiquark Condensates In Strong Magnetic Fields, Alec Schramm, Berndt Muller, Stefan Schramm
Quark-Antiquark Condensates In Strong Magnetic Fields, Alec Schramm, Berndt Muller, Stefan Schramm
Alec J Schramm
We discuss the effect of large external magnetic fields on the QCD vacuum structure. We show that the deformed vacuum leads to substantial changes in the hadronic spectrum.
Higgs Boson Production In Peripheral Heavy-Ion Collisions: Coherent Double-Pomeron Exchange, Alec Schramm, Berndt Muller
Higgs Boson Production In Peripheral Heavy-Ion Collisions: Coherent Double-Pomeron Exchange, Alec Schramm, Berndt Muller
Alec J Schramm
Higgs boson production by coherent double-pomeron exchange in peripheral nuclear collisions at energies of several TeV per nucleon is calculated. It is shown that a trigger on quasi-elastic nuclear collisions strongly suppresses the cross section. The analogous two-photon process is predicted to dominate for collisions of heavy nuclei.
A Calculation Of The Deuteron As A Biskyrmion, Alec Schramm, Yossef Dothan, L. Beidenharn
A Calculation Of The Deuteron As A Biskyrmion, Alec Schramm, Yossef Dothan, L. Beidenharn
Alec J Schramm
No abstract provided.