G.E. SRT-2-IND Deep Therapy Tube

Ref. E15

This heavy and strongly discolored oil-immersed radiotherapy X-ray tube, dating to the fifties, is about 20” (50 cm) long and its largest diameter is five-inch (12.5 cm) wide.

The anode is water-cooled through two tubular extensions (on the left in the picture), one of which is marked “inlet”. The Tungsten target is deep seated in the hooded copper anode.

The filament is a flat helical spiral.

The ground glass X-ray port hides a black metal filter (probably beryllium) fixed by 12 bushings to the anode (made visible in the picture by rubbing the ground glass window with paraffin oil).

Such tubes could be run up to 250 kV or may be more. An intriguing point is the “IND” in its designation. Could it have also been intended for industrial use?

The cost of this tube in 1958 was estimated at about $2450.