wavel.	cross section	error limit

220	1.95e-18	1.9e-19
225	2.39e-18	2.3e-19
230	2.93e-18	7.1e-19
235	1.62e-18	1.4e-19
240	8.70e-19	1.5e-19
245	6.30e-19	1.4e-19
250	6.40e-19	1.5e-19
255	6.70e-19	1.5e-19
260	7.30e-19	1.5e-19
265	8.30e-19	1.7e-19
270	8.90e-19	1.7e-19
275	6.40e-19	8.0e-20
280	4.90e-19	5.0e-20