Table 1.

Radiation output of the SARRP in cGy/min for a range of field dimensions at 35 cm SSD. The Seifert tube was operated at 225 kVp, 13 mA using the larger (3 mm) focal spot, except when noted, with either Al and/or Cu added filtration. A tube current of 3 mA using the smaller (0.4 mm) focal spot was employed for smallest “nozzle” collimator. The output is defined as the dose in water at 1 cm depth.

Field dimensions	Added Filtration	Dose output (cGy/min)
Tertiary Collimators
60 mm × 60 mm*	4 mm Al	378
30 mm × 30 mm*	4 mm Al	334
1.3 mm diameter*	4 mm Al	206
10 mm × 10 mm	0.5 mm Cu + 2 mm Al	131
5 mm × 5 mm	0.5 mm Cu + 2 mm Al	124
1 mm diameter	0.5 mm Cu + 2 mm Al	102
“Nozzle” Collimators
5 mm × 5 mm	0.5 mm Cu	146
3 mm × 3 mm	0.5 mm Cu	122
1 mm diameter	0.5 mm Cu	92
0.5 mm diameter with 0.4 mm focus	0.5 mm Cu	22

^*Adjusted for the 33.5 cm SSD of the measurements by applying an inverse-square correction.