wavel.	cross sect.	error limit

220	3.55e-18	0.75e-18
230	3.87e-18	0.49e-18
240	3.75e-18	0.43e-18
250	3.22e-18	0.37e-18
260	2.21e-18	0.26e-18
270	1.56e-19	0.22e-18
280	7.90e-19	1.00e-19