[en] Narrow nuclear resonances, initially used to calibrate the energy of the Birmingham Radiation Centre 3MV Dynamitron, have proved useful in discovering and identifying accelerator fault conditions Short-term energy stability (over a few minutes) of a few tens of eV is common. However, variations of many kV occur for several days before the failure of a thermionic rectifier. The beam energy ripple, as reflected in the full width at half maximum of narrow (p,γ) resonances, has also been analysed to indicate the frequency causing the bulk of the ripple, thus often leading to the identification and correction of faults. Typical faults usually produce increased ripple at either the 50 Hz or 128 kHz oscillator frequency

[en] We report measurements of laser absorption for high-contrast ultrashort pulses on a variety of solid targets over an intensity range of 10¹³ to 10¹⁸ W/cm². These data give an experimental determination of the target energy content and an indirect measure of dense plasma electrical conductivity. Our calculations accurately reproduce the behavior of aluminum targets, while the other materials show signs of additional absorption mechanisms. At high intensity all target materials reach a ''universal plasma mirror'' state and reflect about 90% of the incident light

[en] This work presents and comments two experimental techniques used at the L.F.E.N. to study some resonances in the ²⁷Al + p reaction. One of them - the energy modulating device - is a comfortable and accurate alternative to the conventional step by step method of measuring resonance yield curves; the other one is a process to resolve decay schemes of closely spaced, overlapped doublet resonances. The general principles of these two techniques are discussed, the computer programme developed in association with them are presented and some results are commented

[en] Precise energies have been measured for resonances in the ²⁷Al(p,γ)²⁸Si and ²⁴Mg(α,γ)²⁸Si reactions. The proton and α-particle energies have been measured with an accuracy of 0.5 x 10^-4 and 1 x 10^-4, respectively. The Esub(P) = 991.88 +- 0.04 keV resonance in the reaction ²⁷Al(p,γ)²⁸Si served as calibration point. From these data the Q-value of the reaction ²⁷Al(p,α)²⁴Mg has been determined as 1600.14 +- 0.21 keV. The new α-particle energies combined with previous measurements of the γ-ray energies lead to Q-values for the reactions ²³Na(α,γ)²⁷Al and ²⁷Al(α,γ)³¹P in good agreement with the 1971 mass tables

[en] An excitation function at 5 degrees has been measured for (π⁺, π^-) double charge exchange on the target nucleus ²⁷Al to both the final ground state and a state at 1.75 MeV of excitation in the final nucleus ²⁷P. These data were obtained over a range of incident pion energies from 100 to 293.4 MeV using the EPICS facility at LAMPF. The shapes of these excitation functions are strikingly different; the excited state showing similar behavior to non-analog, J^π_i=0⁺ to J^π_f=0⁺ transitions and the g.s. data exhibiting an interference-like dip near 150 MeV. This minimum likely involves spin flip because the g.s., ΔJ≠0 transition can involve single spin flip

[en] Quasi-monochromatic photon beams of 108 MeV Compton-edge energy produced in the ROKK-1M facility at the storage ring VEPP-4M (BINP, Novosibirsk) and makrofol sheets as fission track detectors were used to measure the photofission yield of ²⁷Al. The fission yield was found to be (160±55) μb. From this result and previously measured ²⁷Al photofission yield at ∼79 MeV end-point energy with the LADON apparatus, the trends of fission cross section and fissility have been obtained in the incident photon energy range ∼40-110 MeV. The present results and data for other intermediate-mass nuclei obtained with the same methodology indicate an increase of fissility with decreasing Z²/A as predicted by the liquid drop model for fissioning systems lighter than ∼Ag. (author)

[en] The absolute emission probabilities of the 171, 844 and 1014 keV γ-rays in the decay of ²⁷Mg produced by the ²⁷Al(n, p) reaction have been determined 0.85(6)%, 72.0(3)% and 28.0(3)%, respectively, by using an HPGe detector with good accuracy

[en] Short communication

No abstract available

[en] New levels of ₂₆Al located at excitation energies higher than 5.0 MeV were found through the ₂₇Al(₃He,α) reaction. Some of them (5.05 MeV; 10.04 MeV; 10.80 and 11.69 MeV) were identified as isobaric analogs to states in the ₂₆Mg nucleus. Tentative spin assignments were made by analysing the measured angular distributions with the DWBA method. (author)