Mass limits on (νe)-bar from the cryogenic study of the 187Re beta decay

An experiment to study the β-decay of 187Re using a cryogenic μ-calorimeter is presented. The physical motivations for undertaking a rhenium experiment, in the context of providing a limit on the (νe)-bar mass, are briefly discussed. Preliminary results on the 187Re β spectrum, obtained with a NTD-Ge thermistor coupled to a superconducting rhenium crystal, are presented, where the energy resolution is measured by an external 55Fe X-ray source to be σ of 54 eV at 5.9 keV. Future considerations relating to radioactive background, improved detector performance, energy calibration and 187Re β spectral analysis are proposed. (author)