Chalk River Laboratories

About: Chalk River Laboratories is a based out in . It is known for research contribution in the topics: Neutron diffraction & Neutron scattering. The organization has 2297 authors who have published 2700 publications receiving 73287 citations.

Magnetic structure of UPd2Si2.

Abstract: Elastic-neutron-scattering and magnetization measurements have been performed on a single crystal of ${\mathrm{UPd}}_{2}$${\mathrm{Si}}_{2}$ in the 12--160-K temperature range. Two magnetically ordered phases are observed with the magnetic moment parallel to the c axis. At low temperatures (T108 K), there is a simple body-centered-tetragonal antiferromagnet with an ordered moment of 2.3\ifmmode\pm\else\textpm\fi{}0.3${\mathrm{\ensuremath{\mu}}}_{\mathit{B}}$. At higher temperatures (108 KT136 K), there is an incommensurate spin-density wave with wave vector q=(0,0,0.732) and magnetic moment 2.3\ifmmode\pm\else\textpm\fi{}0.3${\mathrm{\ensuremath{\mu}}}_{\mathit{B}}$ at 120 K. The phase transition at 108 K is first order while there is a critical phase transition at 136 K to the paramagnetic phase with critical index \ensuremath{\beta}=0.30\ifmmode\pm\else\textpm\fi{}0.03. The low-temperature phase contains a small amount of a (0,0,2/3) phase; the maximum intensity from this phase is about 0.8% of that from the simple antiferromagnetic phases at 90 K. The magnetization in low field shows an analogous peak at 90 K.

Channel selection for high spin γ-ray spectroscopy studies via total energy measurements in fusion-evaporation reactions

Abstract: A channel selection method for high spin γ-ray spectroscopy studies based on the measurement of the total energy of all radiations (both charged particle and γ-ray) emitted in heavy-ion fusion reactions is presented. The method is applicable to all reactions in which charged-particle evaporation from the compound system dominates, and is particularly effective in isolating the weakly populated low particle multiplicity channels that leave the final nucleus with the greatest spin and excitation energy. The method is illustrated using data taken with the 8π γ-ray spectrometer and the miniball 4π charged-particle detector array at the Chalk River Tandem Accelerator Superconducting Cyclotron (TASCC) facility. Channel-to-total ratios are improved over those obtained with charged-particle detection alone by factors as large as 46 without significant loss of statistics for the selected channel.