Dependence of the energy resolution of a scintillating crystal on the readout integration time

The possibilty of performing high-rate calorimetry with a slow scintillating crystal is studied. In this experimental situation, to avoid pulse pile-up, it can be necessary to base the energy measurement on only a fraction of the emitted light, thus spoiling the energy resolution. This effect was experimentally studied with a BGO crystal and a photomultiplier followed by an integrator, by measuring the maximum amplitude of the signals. The experimental data show that the energy resolution is exclusively due to the statistical fluctuations of the number of photoelectrons contributing to the maximum amplitude. When such number is small its fluctuations are even smaller than those predicted by Poisson statistics. These results were confirmed by a Monte Carlo simulation which allows to estimate, in a general case, the energy resolution, given the total number of photoelectrons, the scintillation time and the integration time

High-speed data transfer with FPGAs and QSFP+ modules

We present test results and characterization of a data transmission system based on a last generation FPGA and a commercial QSFP+ (Quad Small Form Pluggable +) module. QSFP+ standard defines a hot-pluggable transceiver available in copper or optical cable assemblies for an aggregated bandwidth of up to 40 Gbps. We implemented a complete testbench based on a commercial development card mounting an Altera Stratix IV FPGA with 24 serial transceivers at 8.5 Gbps, together with a custom mezzanine hosting three QSFP+ modules. We present test results and signal integrity measurements up to an aggregated bandwidth of 12 Gbps.Comment: 5 pages, 3 figures, Published on JINST Journal of Instrumentation proceedings of Topical Workshop on Electronics for Particle Physics 2010, 20-24 September 2010, Aachen, Germany(R Ammendola et al 2010 JINST 5 C12019

Comparative studies of hemoglobins from newts (Triturus cristatus, triturus vulgaris, triturus alpestris): A kinetic approach

The functional properties of three different species of newts i.e. Triturus cristatus carnifex, Triturus vulgaris meridionalis and Triturus alpestris apuanus have been studied by flash photolysis. In spite of the very different habitats the hemoglobins of the adult form of the three species do not show significant differences in functional behaviour. However the neotenic form of Triturus alpestris apuanus is characterized by the presence of a higher multiplicity of hemoglobin components as compared to that of the adult form. The experiments show that the new hemoglobin(s) is characterized by a more marked pH dependence and by a much higher rate constant for CO combination. This finding may be relevant to the compulsory aquatic life of the neotenic form of this amphibian