TABLE 5.

Calculated values of $k_Q$ for electron beams in various chamber types, as a function of beam quality R ₅₀. ²

	Beam quality R50 (g/cm2)
Ionization chamber type	1.0	1.4	2.0	2.5	3.0	3.5	4.0	4.5	5.0	5.5	6.0	7.0	8.0	10.0	13.0	16.0	20.0
Parallel‐plate chambers
Markus	–	–	0.925	0.920	0.916	0.913	0.910	0.907	0.904	0.901	0.899	0.894	0.889	0.881	0.870	0.860	0.849
Roos	0.965	0.955	0.944	0.937	0.931	0.925	0.920	0.916	0.912	0.908	0.904	0.898	0.892	0.882	0.870	0.860	0.848
Cylindrical chambers
PTW 30013 (Farmer)	–	–	–	–	–	–	0.911	0.909	0.907	0.906	0.904	0.901	0.898	0.893	0.885	0.878	0.868
Scdx‐Wellhofer FC65‐P	–	–	–	–	–	–	0.914	0.912	0.911	0.909	0.907	0.904	0.902	0.896	0.889	0.881	0.872
Scdx‐Wellhofer FC65‐G	–	–	–	–	–	–	0.920	0.918	0.916	0.914	0.913	0.910	0.907	0.902	0.894	0.887	0.877