The behaviour of Monte Carlo criticality simulations is often assessed by examining the convergence of the so-called entropy function. In this work, we shall show that the entropy function may lead to a misleading interpretation, and that potential issues occur when spatial correlations induced by fission events are important. We will support our analysis by examining the higher-order moments of the entropy function and the center of mass of the neutron population. Within the framework of a simplified model based on branching processes, we will relate the behaviour of the spatial fluctuations of the fission chains to the key parameters of the simulated system, namely, the number of particles per generation, the reactor size and the migration area. Numerical simulations of a fuel rod and of a whole core suggest that the obtained results are quite general and hold true also for real-world applications.

No abstract

No abstract

No abstract

In this paper a new system for the remote interrogation of wireless battery-less passive sensors aimed at environmental sensing is presented. The system uses a capacitive sensor configured as an LC-tank which resonant frequency shifts with the physical measurement. The overall performance of the architecture is analyzed with respect to coupling factor and sensor parameters.

No abstract

This paper presents a study of a wireless batteryless passive telemetric system aimed at environmental sensing. The system uses a capacitive sensor configured as an LC-oscillator which resonant frequency shifts with the physical measurement. The expected performance of this system including sensitivity is analyzed with respect for coupling factor and sensor/circuit parameters.I.

No abstract