[en] Work is continuing on a collaborative experiment with experimenters from the Lawrence Berkeley Laboratory to search for neutrinoless double beta decay in Mo¹⁰⁰. We have developed a hybrid, lithium drifted, silicon surface barrier detector 1.5 mm thick and 7.1 cm in diameter which, operating at LN₂ temperature and in conjunction with an Amptek A225 low noise preamplifier and amplifier chip, gives an electronic resolution of 18 keV FWHM. At present, we have 8 working detectors of this type and another 8 currently being fabricated, and we expect to have between 50 and 70 of these detectors working by January 1985. We have also fabricated 5 grams of isotopically pure Mo¹⁰⁰ into 7 micron thick circular foils 7.1 cm in diameter and have constructed a titanium cryostat with an oxygen-free, high conductivity electrolytic (OFHC) copper dipstick which currently contains a stack of 6 detectors and is being used to evaluate backgrounds from the residual natural radioactivity remaining in the detector system. We hope to begin taking data with 5 to 10% of the full array by early 1985