The first run of the ultracryogenic resonant bar detector AURIGA is in progress. Diagnostics on the cryogenics, the data acquisition system and on the noise characteristics have been performed, with results in accord with the design. The bar reached 140 mK. In tests down to 2 K the detector noise was very close to `Brownian'.

No abstract

In the design and development of solid propellant rocket motors (SRMs), the use of numerical tools able to simulate, predict and reconstruct the behavior of a given motor, in all its operative conditions, is particularly important in order to decrease all the planning times and costs.This paper is devoted to propose and present an approach to the numerical simulation of SRM internal ballistics, during the entire combustion time, by means of different own made models. The core of this procedure is represented by the SPINBALL model and numerical code. SPINBALL considers a Q1D unsteady modeling of the SRM internal ballistics, with many different sub-models able to represents all the driving phenomena that characterize the bore chamber flowfield conditions during the SRM timelife, from the motor start-up to burn-out.In particular, the grain burning surface evolution is accomplished by means of a 3D numerical grain regression model, named GREG. This model is based on a full matrix level set approach, on rectangular or cylindrical structured grids. GREG gives to the SPINBALL gasdynamical model the evolution in time of the port area, wet perimeter and burn perimeter along the motor axis and, in case, within the submergence zone.The final objective is, hence, to develop an analysis/simulation capability of SRM internal ballistics, for the entire combustion time, with simplified physical models, in order to reduce the computational cost required, but ensuring, in the meanwhile, an accuracy of the simulation greater than the one usually given by 0D quasi steady models, during quasi steady state and tail off. Notwithstanding, a 0D quasi steady model of SRM internal ballistic has been developed to reconstruct the experimental data coming from static firing tests (SFTs), in order to evaluate non-ideal behaviour parameters, like combustion efficiency, hump law and nozzle efficiency and the nozzle throat area evolution. These parameters are used in the SPINBALL model as inputs.The results of the internal ballistics numerical simulation, from motor start-up to burnout yielded with the SPINBALL model, will be shown for Zefiro23, second solid rocket motor stage developed in the ESA (European Space Agency) project of the new European small launcher Vega.

No abstract

No abstract