ID:
16
before 1920
Dimensions:
11 × 11 × 35 cm
![](https://physicsmuseum.uq.edu.au/system/storage/serve/931/cat016%5B1%5D.gif)
Focussing of cathode rays by a concave cathode was an important feature of early discharge type x-ray tubes as a small emitting spot on the anode gave sharper pictures.
Focussing of cathode rays by a concave cathode was an important feature of early discharge type x-ray tubes as a small emitting spot on the anode gave sharper pictures.