Recent Developments in the Read-Out Electrodes for the Spherical Proportional Counter
Résumé
The spherical proportional counter is a versatile gaseous detector offering many advantages with its relatively simple design comprising a spherical cathode with a centrally-located, spherical anode. With sub-keV energy thresholds, variable gas mixtures, and single channel readout in the simplest form the detector is well suited to many applications from direct dark matter searches to fast neutron spectroscopy. Various improvements to the structure are presented, including improvements to the electric field homogeneity near the anode and detector stability to sparks through the use of high-resistivity second electrodes. Finite element method software was used to study different designs. Developments to improve the electric field homogeneity at larger radii have also been explored and are presented, as well as a multi-anode structure to allow operation at higher pressures or in larger volume detectors.