The CaloCube calorimeter for high-energy cosmic-ray measurements in space: performance of a large-scale prototype

Abstract

The direct observation of high-energy cosmic rays, up to the PeV energy region, will increasingly rely on highly performing calorimeters, and the physics performance will be primarily determined by their geometrical acceptance and energy resolution. Thus, it is extremely important to optimize their geometrical design, granularity and absorption depth, with respect to the total mass of the apparatus, which is amongst the most important constraints for a space mission. CaloCube is an homogeneous calorimeter whose basic geometry is cubic and isotropic, obtained by filling the cubic volume with small cubic scintillating crystals. In this way it is possible to detect particles arriving from every direction in space, thus maximizing the acceptance. This design summarizes a three-year R&D activity, aiming to both optimize and study the full-scale performance of the calorimeter, in the perspective of a cosmic-ray space mission, and investigate a viable technical design by means of the construction of several sizable prototypes. A large scale prototype, made of a mesh of 5 × 5 × 18 CsI(Tl) crystals, has been constructed and tested on high-energy particle beams at CERN SPS accelerator. In this paper we describe the CaloCube design and present the results relative to the response of the large scale prototype to electrons.

Design of an Antimatter Large Acceptance Detector In Orbit (ALADInO)

“…The design of the ALADInO calorimeter is based on the CaloCube R&D project [159][160][161], which, for the first time, has paved the way for the optimization of a calorimeter concept specifically designed for the measurement of particles impinging isotropically on the calorimeter. This concept well fits with the geometry of the ALADInO spectrometer.…”

“…The comparison between the energy deposit in the calorimeter and the rigidity measurement by the tracker provides additional e/p separation capabilities to the whole detector. In the framework of the CaloCube project [159,161,168] preliminary simulations of the proton rejection capabilities for a similar calorimeter composed of 20 × 20 × 20 cubic Cesium Iodide (CsI) crystals with 3.6 cm side for a total depth of 39 X 0 have been performed, showing e/p separation factors close to 10 5 achieved with the standalone information from the calorimeter. Since the ALADInO calorimeter will be much deeper, will have a similar segmentation, and will profit also from the independent measurement of the particle rigidity with the spectrometer in the TeV energy range, we expect to reach a e/p separation capability of at least 10 5 .…”

Development of the photo-diode subsystem for the HERD calorimeter double-readout

“…The characterization of FEE employed by CaloCube is summarized in [13], while the performance measured with high energy particle beams are discussed in [16][18] [19]. In view of the HERD experiment, several updates of the electronics were carried out.…”

“…Each HiDRA-2 chip has 16 input channels whose analog output is multiplexed to a single output pin. A detailed description of the front-end electronics calibration procedure can be found in [16]. The FEE is driven by a data acquisition system (DAQ) developed by CIEMAT-Madrid.…”

The High Energy Cosmic-Radiation Detection (HERD) facility for direct cosmic-ray measurements.

“…The first one is based on wavelength-shifting fibers read out by intensified scientific CMOS cameras [14], while the second on photodiodes directly attached to the LYSO cubes [18]. The two systems have been extensively prototyped and tested, both with Monte Carlo simulations and with particle beams [15][16][17] The FIT [19] will be the main tracking device. It is currently made of 7 double layers of scintillating fibers on each of the 5 sides of the calorimeter, read by silicon photomultipliers (SiPMs).…”