Frequency encoded all optical single bit memory unit using difference frequency generation alone

A method of all optical frequency encoded single bit memory unit is proposed and described using difference frequency generation only in non linear materials. The unit can store a single bit in frequency encoded format and thus maintains the same state when input is withdrawn. To change the state of the information of the memory unit the input should be changed. The proposed memory unit employs difference frequency generation for its operation and is very fast, the speed of operation is limited by the difference frequency generation process.     

A numerical experiment in DLCQ: microcausality, continuum limit and all that

Issues related with microcausality violation and continuum limit in the context of (1+1) dimensional scalar field theory in discretized light-cone quantization (DLCQ) are addressed in parallel with discretized equal time quantization (DETQ) and the fact that Lorentz invariance and microcausality are restored if one can take the continuum limit properly is emphasized. In the free case, it is shown with numerical evidence that the continuum results can be reproduced from DLCQ results for the Pauli–Jordan function and the real part of Feynman propagator. The contributions coming from k⁺ near zero region in these cases are found to be very small. In the interacting case, aspects related to the continuum limit of DLCQ results in perturbation theory in momentum space are discussed.     

Doubly excited triplet states of highly stripped ions

Transition energies, Coulomb repulsions and effective quantum numbers have been calculated for the doubly excited Nsnp: ³P⁰ (for N = 2, n = N,?, 5n = N,\ldots, 5); Nsnd: ³D^e (for N = 2, n=N+1, ?, 5n=N+1, \ldots, 5) and Npnd: ³F⁰ (for N = 2, n=N+1, ?, 5n=N+1, \ldots, 5) states for the highly stripped ions Na⁹⁺{\rm Na^{9+}}, Mg¹⁰⁺\rm Mg^{10+}, Al¹¹⁺\rm Al^{11+}, Si¹²⁺\rm Si^{12+}, P¹³⁺\rm P^{13+} and S¹⁴⁺\rm S^{14+}. Time-dependent perturbation theory has been applied to calculate such transitions properties. A time-dependent harmonic perturbation causes simultaneous excitation of both the electrons with a change of spin state. The doubly excited energy levels and the analytic representation of their wave functions are obtained by identifying the poles of an appropriately constructed linearized variational functional with respect to driving frequency. Most of the results are new. The transition energies and effective quantum numbers of 2s2p: ³P⁰ states of all the ions agree well with the only available experimental data.     

A novel frequency encoded all optical CNOT gate exploiting difference frequency generation and implementation of fast binary adders using frequency encoding and nonlinear dielectric films

Optics has an important role in logic implementation and computation is established in two and half decades by many researchers. Recently frequency encoding technique is established. This technique does not suffer from intensity dependent loss problems like other schemes. Amorphous dielectric thin films with reflecting edges can also be used for logic realization and has very fast response speed. It also does not use any semiconductor device and simple to construct. In this communication the authors have proposed all optical CNOT gate using frequency encoded difference frequency generation exploiting nonlinear response of some material and implementation of binary adders by CNOT gate and dielectric thin film AND gate.     

Working group report: Quantum chromodynamics sub-group

This is the report of the QCD working sub-group at the Tenth Workshop on High Energy Physics Phenomenology (WHEPP-X).      

Complete structure determination of the astrophysically important nucleus Na below the proton threshold

The fusion–evaporation reaction ¹⁰B(¹²C, 2n) was used to make the first observation of in-beam γ decays from the astrophysically important nucleus ²⁰Na, lying adjacent to the proton drip-line. All states below the proton threshold in ²⁰Na were populated and identified in the experiment. These include new levels, previously unresolved levels, and states located with improved energy precision. The level structure of ²⁰Na, and its γ transitions, are compared to the mirror partner ²⁰F measured simultaneously in this experiment. In particular, a high degree of energy stability is found for all negative parity states. These results are discussed in the context of the nuclear shell model.     

Working group report: Neutrino and astroparticle physics

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.     

Stored energy release behaviour of disordered carbon

The use of graphite as a moderator in a low temperature thermal nuclear reactor is restricted due to accumulation of energy caused by displacement of atoms by neutrons and high energetic particles. Thermal transients may lead to a release of stored energy that may raise the temperature of the fuel clad above the design limit. Disordered carbon is thought to be an alternative choice for this purpose. Two types of disordered carbon composites, namely, CB (made up of 15 wt. % carbon black dispersed in carbonized phenolic resin) and PAN (made up of 20 vol. % chopped polyacrylonitrile carbon fibre dispersed in carbonized phenolic resin matrix) have been irradiated with 145 MeV Ne⁶⁺ ions at three fluence levels of 1.0×10¹³, 5.0×10¹³ and 1.5×10¹⁴ Ne⁶⁺/cm², respectively. The XRD patterns revealed that both the samples remained disordered even after irradiation. The maximum release of stored energy for CB was 212 J/g and that of PAN was 906 J/g. For CB, the release of stored energy was a first order reaction with activation energy of 2.79 eV and a frequency factor of 3.72×10²⁸ per second. 13% of the defects got annealed by heating up to 700 °C. PAN showed a third-order release rate with activation energy of 1.69 eV and a frequency factor of 1.77×10¹⁴ per second. 56% of the total defects got annealed by heating it up to 700 °C. CB seems to be the better choice than PAN as it showed less energy release with a slower rate. PACS 61.80.Jh; 61.80.-x; 61.43Er; 61.43.-j; 68.43.Vx