Search results for "scattering experiments"
showing 2 items of 2 documents
Phonons of hexagonal BN under pressure: Effects of isotopic composition
2021
Raman scattering experiments on isotopically enriched hexagonal boron nitride have been performed under pressure up to 11 GPa at room temperature. The sublinear increase of the Raman-active E2g mode frequencies has been characterized. The pressure behavior has been analyzed by means of a bond-stiffness–bond-length scaling parameter γ which takes into consideration the vast differences in a- and c-axis compressibilities. The interlayer shear mode exhibits a γ parameter similar to that of graphite, and the mode frequency in isotopically pure samples separates faster at low pressures as a result of van der Waals interactions. Because of the extremely low a-axis compressibility, the intralayer …
High-resolution scattering experiments at the K130 cyclotron in Jyväskylä
2018
Abstract An experimental setup for nuclear reaction studies induced by light and heavy ions is described. It consists of a versatile Large Scattering Chamber equipped with two rotating tables for mounting detectors. A dedicated beam diagnostic system is used to monitor the energy spectrum of the beam on target. The system provides the necessary feedback for tuning of the K-130 cyclotron to reduce the energy spread of the accelerated beam by at least a factor of 3 down to about 0.3% of the nominal energy while maintaining beam currents around 20 pnA. At lower beam currents a 0.1% energy spread can be achieved. This improvement makes a significant impact on the scope of reaction studies possi…