33 × 23 × 15 cm

6/six/No 37592
Blown glass tube with anode, anticathode and focus cathode. Electrodes are connected to soldered terminals by wires. Side discharge tube with anode and cathode. Sealed, rubber capped exhaust tube. Glass discoloured due to radiation damage or metal deposits. The cathode focuses an electron beam to a small spot on the anticathode, where they are absorbed. This excites atoms in the anticathode, which relax by emitting X-ray photons. X-rays emerge from the side of the tube and since they emanate from a small spot on the anticathode, X-ray images are sharp. The extra anode allows a larger current to pass without damaging the anticathode. The side tube is used to release (previously occluded) gas into the main chamber. This is to counteract the occlusion of gas that occurs during operation and which lowers the pressure until the discharge ceases. Tubes of this kind were used in medicine and for further X-ray experimentation.