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We designed a CMOS frontend for the readout of scintillators coupled with silicon photodiodes for nuclear physics experiments. The preamplifier features a continuous-reset feedback and an input pMOS transistor. The designed input dynamic range is 90-MeV silicon equivalent. The frontend has been integrated in single channel and multichannel versions up to 16-channel application specific integrated circuits (ASICs) in the C35B4C3 AMS technology. The measured integral-non-linearity over the whole dynamic range is below 0.5%. The intrinsic rise time (10%–90%) of the preamplifier is of the order of 3 ns over the entire dynamic range and is below 50 ns when coupled with a 130-pF photodiode. We qualified the spectroscopic performance by acquiring spectra of a mixed nuclei \alpha source and of different \gamma sources (137Cs and 60Co) with a CsI(Tl) scintillator crystal 3.2~\text cm\times 3.2~\text cm\times 6~\text cm coupled with a 18~\text mm\times 18~\text mm silicon p-i-n diode 300- \mu \textm -thick readout by the developed ASIC. [ABSTRACT FROM AUTHOR]

This article presents a new semi-automatic method for charge and mass identification of charged nuclear fragments using either Δ E − E correlations between measured energy losses in two successive detectors or correlations between charge signal amplitude and rise time in a single silicon detector, derived from digital pulse shape analysis techniques. In both cases different nuclear species (defined by their atomic number Z and mass number A ) can be visually identified from such correlations if they are presented as a two-dimensional histogram (‘identification matrix’), in which case correlations for different species populate different ridge lines (‘identification lines’) in the matrix. The proposed algorithm is based on the identification matrix's properties and uses as little information as possible on the global form of the identification lines, making it applicable to a large variety of matrices. Particular attention has been paid to the implementation in a suitable graphical environment, so that only two mouse-clicks are required from the user to calculate all initialization parameters. Example applications to recent data from both INDRA and FAZIA telescopes are presented. [ABSTRACT FROM AUTHOR]

Abstract: In this work it has been shown theoretically that a single fully depleted n-type silicon surface barrier detector may be used as a ΔE-E telescope for identification of charged particles of very low-Z. A thin slice of the detector at the positive end is assumed as the ΔE detector and the rest part up to the negative end as the E detector. A mathematical formulation for the energy lost by an incident charged particle in the ΔE part of the detector is made. A comparison is made between the telescopes converted from n-type and p-type detectors. The procedure to evaluate a detector suitable for a required telescope is described. The basic technique of a module named ‘preset pulse clipper’, which may be required in connection with the estimation of the energy lost in the ΔE part, is proposed. The possibility of reproducing the basic principle of the ‘preset pulse clipper’ by means of digital sampling and software based processing techniques is explored. The possible superiorities of this type telescope over the traditional ‘two detector ΔE-E telescope’ are discussed. [ABSTRACT FROM AUTHOR]

Abstract: PAMELA is a space telescope orbiting around the Earth since June 2006. The scientific objectives addressed by the mission are the measurement of the antiprotons and positrons spectra in cosmic rays, the hunt for antinuclei as well as the determination of light nuclei fluxes from hydrogen to oxygen in a wide energy range and with very high statistics. The apparatus comprises a time-of-flight system, a magnetic spectrometer, a silicon–tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail catcher scintillator and a neutron detector. In this paper charge identification capabilities of these devices, together with preliminary results concerning isotope abundance, will be presented. [Copyright &y& Elsevier]

The capability of digital pulse shape technique to acquire data from CHIMERA detection cells (Si-CsI(Tl) telescopes) has been evidenced in our previous works. We have now applied this technique to the charge discrimination of the products stopped in the silicon detectors. Large area totally depleted CHIMERA planar silicon detectors (5 cm × 5 cm area, 300 µm thick) in both rear and front side injection have been used. In preliminary tests full charge identification for the reaction products up to Z = 11 have been obtained for products both crossing (ΔE-E technique) and stopping in the silicon detector, using a 21 MeV/u 20Ne beam at the LNS Superconducting Cyclotron in Catania. The quality of the obtained results clearly indicates that the digital signal processing approach is able to give excellent results in this application, too. [ABSTRACT FROM AUTHOR]

The detector of the E865-collaboration at the Brookhaven-AGS described here combines a magnetic spectrometer for the charged decay products of 6 GeV/c K+ with excellent electromagnetic calorimetry and efficient particle identification for electrons and muons. Its high-resolution, large acceptance and high rate capability made it well suited for the study of extremely rare or forbidden decays with multi-leptonic final states such as K+→π+μ+e−, K+→π+l+l−, K+→l+νle−e+ and K+→π+π−e+νe down to branching ratios below 10−11 in an intense K+ beam (≈108 per AGS spill). [Copyright &y& Elsevier]