Table 2.

Permeability P_HF, characteristic lengths L_C, and parameter β.

	CO 2
	PHF × 1012 (mol m−1 s−1 Pa−1)	LC (µm)	β × 10−1	β × 10−1	R 2
FF	2.0 ± 0.4	26 ± 8			0.997
CC	2.0		2.2 ± 0.1		0.999
FC	2.0			2.2 ± 0.1	0.993
N 2
	P HF × 10 13 (mol m −1 s −1 Pa −1 )	L C (µm)	β × 10−2	β × 10−2	R 2
FF	2.3 ± 0.4	14±4			0.998
CC	2.3		2.0 ± 0.4		0.999
FC	2.3			2.0±0.4	0.995
He
	P HF × 10 13 (mol m −1 s −1 Pa −1 )	L C (µm)	β × 10−3
FF	3 ± 1	13 ± 3
FC			5 ± 2
CH 4
	P HF × 10 13 (mol m −1 s −1 Pa −1 )	L C (µm)	β × 10−2
FF	5 ± 1	17 ± 4
FC			2.3±0.9