A Geiger counter is a device used to detect radiation, and consists of a thin metal wire (anode) at the center of a metallic tube (cathode). As radiation enters the tube, electrons are knocked off from the gas inside the tube or from the metallic wall, and accelerate towards the wire at the center. Consider a Geiger counter with an evacuated tube (a vacuum existing between cathode and anode), where the inner anode has a radius 4 mm and the outer cathode has a radius of 82 mm. The anode has a linear charge density of +18 nC/m, while the cathode has a charge per unit length of -18 nC/m. Let the cathode potential be equal to zero (using it as voltage reference). What is the potential at a distance of 142 mm from the center? Express your answer up to four significant figures. Anode Cathode

A Geiger counter is a device used to detect radiation, and consists of a thin metal wire (anode) at the center of a metallic tube (cathode). As radiation enters the tube, electrons are knocked off from the gas inside the tube or from the metallic wall, and accelerate towards the wire at the center. Consider a Geiger counter with an evacuated tube (a vacuum existing between cathode and anode), where the inner anode has a radius 4 mm and the outer cathode has a radius of 82 mm. The anode has a linear charge density of +18 nC/m, while the cathode has a charge per unit length of -18 nC/m. Let the cathode potential be equal to zero (using it as voltage reference). What is the potential at a distance of 142 mm from the center? Express your answer up to four significant figures. Anode Cathode