The CV1141 is an argon filled gas discharge valve or thyratron. The prototype was the GDT4C. The old name was the NGT1 and this indicates a pre-CV UK Navy specification.
The finned structure is the anode. The control electrode, or grid, is a vertical rod placed between the cathode and surrounding anode.
The maximum operating frequency was 10,000 pulses per second. The drop across the valve was 15 - 18 Volts and the control ratio was 40.
The main anode plate with fins attached.
A closer view.
The central oxide coated cathode with grid rods at the side.
The vertical supports for the annular rings of the fins.
The classic envelope is 44 mm in diameter and, excluding the B5 base pins, is 113 mm tall.