Characterization of the JUDIDT Readout Electronics for Neutron Detection

The Group for the development of neutron and gamma detectors in the Central Institute of Engineering, Electronics and Analytics (ZEA-2) at Forschungszentrum Juelich (FZJ) has developed, in collaboration with European institutes, an Anger Camera prototype for improving the impact point reconstruction of neutron tracks. The detector is a chamber filled with $^3He+CF_4$ gas for neutron capture and subsequent production of a tritium and a proton. The energy deposition by the ions gives rise to drifting electrons with an avalanche amplification as they approach a micro-strip anode structure. The scintillating light, generated during the electron drift and avalanche stage, is collected by four vacuum photomultipliers. The position reconstruction is performed via software algorithms. The JUDIDT readout electronics was modified at ZEA-2 to cope with the data acquisition requirements of the prototype. The results of the commissioning of the electronics are here presented and commented.Comment: Corresponding Author: R. Fabbri; 22 pa

DoI position resolution in a continuous LaBr3(Ce) scintillation crystal for gamma-ray imaging

A Monte Carlo simulation of a 50mm 750mm 74mm continuous crystal has been developed to investigate the correlation between the scintillation light width (\u3c3) and the Depth of Interaction (DoI) within the crystal. Our studies are based on a LaBr3(Ce) crystal, in order to take advantage of its high light yield to reduce the statistic uncertainties on the estimators of the \u3c3. The first one, the standard deviation of the light distribution, has demonstrated a poor, though linear, correlation to DoI, that is not experimentally detectable. Otherwise, the second estimator,N/I, is the ratio of the total number of photoelectrons to the maximum number of photoelectrons collected from a single anode, in a scintillation event. N/I has been found to have the best correlation to DoI, that provides 2 mm resolution

Observation of a peaking structure in the J/psi phi mass spectrum from B-+/- -> J/psi phi K-+/- decays

A peaking structure in the J/ψφ mass spectrum near threshold is observed in B ±→J/ψφK± decays, produced in pp collisions at √s=7 TeV collected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/ψ, corresponds to an integrated luminosity of 5.2 fb-1. Fitting the structure to an S-wave relativistic Breit-Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m = 4148.0 ± 2.4 (stat.) ± 6.3 (syst.)MeV and Γ=28-11 +15(stat.)±19(syst.)MeV, respectively. Evidence for an additional peaking structure at higher J/ψφ mass is also reported. © 2014 The Authors