Table 2.

Radiation barriers, design limits, and measured values for dose equivalent rates with the accelerator producing 18 MV at 600 MU/min. These rates are for the worst‐case irradiation condition (e.g., for a primary barrier, the beam is directed at the barrier). The design limit is the predicted total dose equivalent rate for the barrier using the limiting transmission factor from Table 1.

Barrier ID	Location	Design limit $\mu \text{Sv}/\mathrm{h}$	Measured photons $\mu \text{Sv}/\mathrm{h}$	Measured neutrons $\mu \text{Sv}/\mathrm{h}$	Total $\mu \text{Sv}/\mathrm{h}$
P1, P2	side walls	20	8.5	$<0.5$	$<9.0$
P1a, P2a	above 3.2 m	800	300	$<0.5$	300
P3	roof	4000	2200	40	2240
S1	front wall	24	0.1	2.0	2.1
S1a	door	24	0.4	3.0	3.4
S2	back wall	19	0.3	$<0.5$	$<0.8$
S3, 4	side walls	19	1.7	$<0.5$	$<2.2$
S5	roof	80	25	$<0.5$	25