SysRT: A Modular Multiprocessor RTOS Simulator for Early Design Space Exploration

International audienc

A Variable Current Bypass Shunt for Electromagnets

An IGBT is used to control the current in bypass circuits that vary the relative strength of magnets connected in series. Each circuit consists of a water cooled assembly rated for continuous operation at 70 Volts and 0--50 Amperes DC, with 1 KV insulation between control/monitoring elements and magnets. The circuit operates as a 10KHz PWM switcher that includes filters and transient protection

Charged Current Quasi-Elastic Interactions at MiniBooNE Confront Cross Section Monte Carlos

Neutrino oscillations have been established in solar and atmospheric neutrinos, but a third signal from the LSND experiment is incompatible with three Standard Model neutrinos. The MiniBooNE experiment can confirm or refute the LSND signal with 1E21 protons on target. While working towards the oscillation result, MiniBooNE will accumulate more than 1E6 neutrino interactions in the 0 to 2 GeV range which will greatly increase the world's knowledge of neutrino cross sections in this energy regime. Preliminary results on the MiniBooNE muon neutrino charged current quasi-elastic analysis are presented and compared to the NUANCE, NEUT, and NEUGEN cross section Monte Carlos.Comment: Proceedings for the NuInt04 Conference, 7 pages, 10 figure

Determining the sign of Δ31\Delta_{31} at long baseline neutrino experiments

Recently it is advocated that high intensity and low energy $(E_\nu \sim 2 GeV)$ neutrino beams should be built to probe the $(13)$ mixing angle $\phi$ to a level of a few parts in $10^4$. Experiments using such beams will have better signal to background ratio in searches for $\nu_\mu \to \nu_e$ oscillations. We propose that such experiments can also determine the sign of $\Delta_{31}$ even if the beam consists of {\it neutrinos} only. By measuring the $\nu_\mu \to \nu_e$ transitions in two different energy ranges, the effects due to propagation of neutrinos through earth's crust can be isolated and the sign of $\Delta_{31}$ can be determined. If the sensitivity of an experiment to $\phi$ is $\epsilon$, then the same experiment is automatically sensitive to matter effects and the sign of $\Delta_{31}$ for values of $\phi \geq 2 \epsilon$.Comment: Title changed and paper rewritten. 4 pages, 1 figure, revte

Muon Spectra of Quasi-Elastic and 1-Pion Production Events in LBL Neutrino Oscillation Experiments

The muon energy spectra of the quasi-elastic and 1-pion production events in a LBL experiment, like K2K, are predicted to follow closely the neutrino energy spectrum, with downward shifts of the energy scale by $/2 M$ and $( + M_\Delta^2 - M^2)/2 M$ respectively. These predictions seem to agree with the observed muon spectra in the K2K nearby detector. The corresponding muon spectra in the far-away (SK) detector are predicted to show characteristic spectral distortions induced by $\nu_\mu$ oscillation. Comparison of the predicted spectral distortions with the observed muon spectra of the 1-Ring and 2-Ring muon events in the SK detector will help to determine the oscillation parameters. The results will be applicable to other LBL experiments as well.Comment: 13 pages. One figure and a few comments added, final version to appear in P

Matter effects in long baseline experiments, the flavor content of the heaviest (or lightest) neutrino and the sign of Delta m^2

The neutrinos of long baseline beams travel inside the Earth's crust where the density is approximately rho = 2.8 g cm^-3. If electron neutrinos participate in the oscillations, matter effects will modify the oscillation probabilities with respect to the vacuum case. Depending on the sign of Delta m^2 an MSW resonance will exist for neutrinos or anti-neutrinos with energy approximately E_nu(res) = 4.7 |\Delta m^2|/(10^-3 eV^2) GeV. For Delta m^2 in the interval indicated by the Super-Kamiokande experiment this energy range is important for the proposed long baseline experiments. For positive Delta m^2 the most important effects of matter are a 9% (25%) enhancement of the transition probability P(nu_mu -> nu_e) for the KEK to Kamioka (Fermilab to Minos and CERN to Gran Sasso) beam(s) in the energy region where the probability has its first maximum, and an approximately equal suppression of P(antinu_mu -> antinu_e). For negative Delta m^2 the effects for neutrinos and anti-neutrinos are interchanged. Producing beams of neutrinos and antineutrinos and measuring the oscillation probabilities for both (nu_mu -> nu_e) and (antinu_mu -> antinu_e) transitions can solve the sign ambiguity in the determination of Delta m^2.Comment: Latex, 28 pages, 12 postscript figure

The Merging System Am 2049-691

Spectroscopic and photometric observations of the peculiar object AM 2049-691 are presented here. Its systemic velocity is V(GSR) = (10956 +-30) km/s, and the derived distance (H(0) = 75 km/s/Mpc) results 146 Mpc. A bridge is observed between two very distinct nuclei whose separation is about 10 kpc, as well as two tails that emerge from the extremes SW and NE of the main body and extend up to 41 and 58 kpc respectively. The spectral characteristics of the all observed zones are typical of H II regions of low excitation. The internal reddening is quit high, particularly in the NE nucleus. All the derived equivalent widths of the H(alpha)+[N II] lines indicate enhanced star formation compared with isolated galaxies, specially in the NE nucleus; the equivalent width corresponding to the integrated spectrum reflects starburst activity in the whole object, and is compatible with a merger of two disk galaxies. All the observed characteristics of AM 2049-691 indicate it is a merger, where a overabundance of nitrogen is detected in one of the nuclei, which has the most evolved population and would be the most massive one. The detected total IR emission is not very high. The integrated total color B - V corresponds to a Sc-Scd galaxy and its average integrated population is about F7 type. Indicative B - V colors of the nuclei, corrected for internal absorption, are in agreement with the spectroscopic results. The central radial velocity dispersions at the nuclei suggest that the most massive galaxy would be the progenitor of the SW component. The observed radial velocity curve shows the presence of two subsystems, each one associated with a different nucleus.Comment: 5 pages, 4 figure