Williams, F C, and Kilburn, I, A Storage System for Use with Binary Digital Computing Machines, ProcIEE, Part III, No.40 (March, 1949).
The Williams tube was initially based on the CV1131, a commercially available 12-inch (300 mm) diameter CRT, but a smaller 6-inch (150 mm) tube, the CV1097, was used in the SSEM.
A Williams-Kilburn tube
Display on screen. Image formed by the focus method