arXiv subjects
Publications and source records attributed to C. Grieb.
Sterile neutrino ($ν_s$) conversion in meter scale baselines can be sensitively probed using mono-energetic, sub-MeV, flavor pure $ν_e$'s from an artificial MCi source and the unique technology of the LENS low energy solar $ν_e$ detector. Active-sterile {\em oscillations} can be directly observed in the granular LENS detector itself to critically test and extend results of short baseline accelerator and reactor experiments.
The LENA (Low Energy Neutrino Astronomy) detector is proposed to be a large-volume liquid-scintillator device which will be highly suitable for the investigation of a variety of topics in astrophysics, geophysics and particle physics. In this paper, the potential of such a detector concerning the search for proton decay in the SUSY favored decay channel p->K+antineutrino is investigated. Based on Geant4, Monte Carlo simulations of the proton decay in the LENA detector as well as of the background radiation in the detection energy windows have been developed. From these simulations an efficiency of 65% for the detection of a possible proton decay has been determined. Within ten years of measuring time a lower limit for the proton lifetime, concerning the decay channel investigated, of tau>4.10^{34} y could be reached.
Light concentrators for the solar neutrino experiment Borexino and the Counting Test Facility (CTF) have been developed and constructed. They increase the light yield of these detectors by a factor of 2.5 and 8.8, respectively. Technical challenges like long term stability in various media, high reflectivity and radiopurity have been addressed and the concepts to overcome these difficulties will be described. Gamma spectroscopy measurements of the concentrators show an upper limit of 12e-6 Bq/g for uranium and a value of 120e-6 Bq/g for thorium. Upper limits on other possible contaminations like 26Al are presented. The impact of these results on the performance of Borexino and the CTF are discussed and it is shown that the design goals of both experiments are fulfilled.