PRELIMINARY-RESULTS IN THE CONSTRUCTION OF A 2D IMAGING DEVICE WITH METASTABLE SUPERCONDUCTING GRAINS

We have built and tested a 16 x 16 channel 2D matrix detector based on metastable superconducting grains. The camera was constructed from different thicknesses and size distributions of tin grains in paraffin, placed between two orthogonal planes of pickup coils and operated at 1.5 K. The homogeneity of the response curves of the 100 central pixels was better than 1.3%. Test objectives were provided by short range electron sources of S-35 and C-14, of varying geometries, placed in close proximity to the suspension. Each pixel was 700 x 700 mum2, and was separated from its nearest neighbour by 2000 microns. Preliminary images have been obtained without collimating optics or maskings, and an image reconstruction limited to analysis of the transition slopes of the nucleated grains. Analysis suggests a single pixel resolution. Prospects for the construction of a 3D tracking detector are considered.