A Geiger-Mueller tube is a radiation detector that consists of a closed, hollow, metal cylinder (the cathode) of inner radius ra and a coaxial cylindrical wire (the anode) of radius rb (see figure below) with a gas filling the space between the electrodes. Assume that the internal diameter of a Geiger-Mueller tube is 1.90 cm and that the wire along the axis has a diameter of 0.210 mm. The dielectric strength of the gas between the central wire and the cylinder is 1.15 106 V/m. Use the equation 2pi·rℓE = qin/ε0

to calculate the maximum potential difference that can be applied between the wire and the cylinder before breakdown occurs in the gas.