Photovoltaic spectroscopy of InGaAsP/InP multiple quantum wells

Photovoltaic Spectroscopy is used to study lattice matched Au/InGaAsP/InP multiple quantum wells at 4.2 < T < 300 K. Four quantum transitions are clearly identified in the spectra and their temperature shift mapped. The Au/InGaAsP Schottky barrier is found to be nearly temperature independent at \u3c6B 0.68 eV, and the binding energy of the 11H associated exciton estimated at Eb 11 meV. The 11H exciton displays a small electric field shift, to the red at low T, changing over to a blue shift at higher temperatures.NRC publication: Ye

Monte Carlo Simulations for Shielding Analysis of the TR-24 Cyclotron at INRNE-BAS

Abstract The Institute for Nuclear Research and Nuclear Energy at the Bulgarian Academy of Sciences is building an accelerator laboratory to operate a TR-24 cyclotron. Thus, a preliminary radiation shielding analysis of the accelerator bunker is required. For this purpose Monte-Carlo simulations have been performed and dosimetric (Dose equivalent) quantities have been estimated in two model geometries - simplified spherical geometry and full-scale bunker, respectively during operation and after the end of the cyclotron life. Our current efforts are directed to the production of 18F thus in all the conducted simulations a water target enriched with 18O is considered. NiGa3 as a target for production of 68Ge has also been simulated and a comparison of the radiation shielding characteristics of the bunker for the two targets has been made.</jats:p

Cyclotron project of the Institute for Nuclear Research and Nuclear Energy

Abstract We present the cyclotron project of the Institute for Nuclear Research and Nuclear Energy which aims to centralize national the production of radioisotopes and radiopharmaceuticals and to provide opportunities for interdisciplinary research and education in the fields of Physics, Chemistry, Biology and Nuclear Energy. The human resources needed for the successful operation of the production program of the centre are also described in this article. An account of the ongoing research related to the radiation protection and radiation shielding of the cyclotron is made.</jats:p

Nuclear Structure Investigations in 30^{30}P

International audienceNew results for the branching ratios of the positive parity band in the N=Z nucleus $^{30}$P are presented. The data are extracted from the experiment at the laboratory Nazionali di Legnaro, Italy, using the GASP spectrometer with the reaction $^{20}$Ne($^{12}$C, pn)$^{30}$P. The excited states of $^{30}$P are obtained from the strongest reaction channel. The good statistics of the data allows us to determine reliable branching ratios, which we report for the first time. Comparison with the theoretical predictions published earlier shows a remarkable agreement between the experiment and shell model calculations

Nuclear structure studies in mirror nuclei

International audienceThe nuclear structure of the A=31 and A=47 mirror couples produced by two fusion evaporation reactions has been elaborated, utilizing the Doppler-shift attenuation method. Excited states in $^{31}$P and $^{31}$S were populated using the 1p and 1n exit channels, respectively, of the reaction $^{20}$Ne + $^{12}$C, while in $^{47}$Cr and $^{47}$V couple excited states were populated based on $^{28}$Si + $^{28}$Si reaction, as products of 2αn and 2αp exit channels. The A=31 mirror couple was studied utilizing Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro with GASP multidetector array and for A=47 one - with the EUROBALL array using XTU Tandem also in Legnaro. In both cases the lifetime measurements in mirror couples at the same experiment open possibilities for investigations of isospin symmetry. Determined B(E1) strengths in the mirror nuclei $^{31}$P and $^{31}$S allow to extract the isoscalar component, which can reach up to 24% of the isovector one. The B(E1) values can be modeled by the Equation of motion method. In the case of A=47 mirror couple, the quadrupole moments can be described by shell-model calculations

Nuclear structure studies in mirror nuclei

The nuclear structure of the A=31 and A=47 mirror couples produced by two fusion evaporation reactions has been elaborated, utilizing the Doppler-shift attenuation method. Excited states in 31P and 31S were populated using the 1p and 1n exit channels, respectively, of the reaction 20Ne + 12C, while in 47Cr and 47V couple excited states were populated based on 28Si + 28Si reaction, as products of 2an and 2ap exit channels. The A=31 mirror couple was studied utilizing Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro with GASP multidetector array and for A=47 one - with the EUROBALL array using XTU Tandem also in Legnaro. In both cases the lifetime measurements in mirror couples at the same experiment open possibilities for investigations of isospin symmetry. Determined B(E1) strengths in the mirror nuclei 31P and 31S allow to extract the isoscalar component, which can reach up to 24% of the isovector one. The B(E1) values can be modeled by the Equation of motion method. In the case of A=47 mirror couple, the quadrupole moments can be described by shell-model calculations

Nuclear structure studies in mirror nuclei

Abstract The nuclear structure of the A=31 and A=47 mirror couples produced by two fusion evaporation reactions has been elaborated, utilizing the Doppler-shift attenuation method. Excited states in 31P and 31S were populated using the 1p and 1n exit channels, respectively, of the reaction 20Ne + 12C, while in 47Cr and 47V couple excited states were populated based on 28Si + 28Si reaction, as products of 2αn and 2αp exit channels. The A=31 mirror couple was studied utilizing Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro with GASP multidetector array and for A=47 one - with the EUROBALL array using XTU Tandem also in Legnaro. In both cases the lifetime measurements in mirror couples at the same experiment open possibilities for investigations of isospin symmetry. Determined B(E1) strengths in the mirror nuclei 31P and 31S allow to extract the isoscalar component, which can reach up to 24% of the isovector one. The B(E1) values can be modeled by the Equation of motion method. In the case of A=47 mirror couple, the quadrupole moments can be described by shell-model calculations.</jats:p