wavel.	cross section 	error limit

200	1.40e-18	3.0e-19
205	1.40e-18	2.5e-19
207	1.40e-18	1.5e-19
210	1.70e-18	2.6e-19
215	2.10e-18	2.3e-19
220	2.63e-18	1.7e-19
225	3.00e-18	1.5e-19
230	3.47e-18	2.2e-19
235	3.97e-18	1.1e-19
240	4.18e-18	1.7e-19
245	4.20e-18	1.7e-19
250	4.00e-18	2.5e-19
255	3.83e-18	4.6e-19
260	3.15e-18	4.1e-19
265	2.60e-18	1.7e-19
270	2.07e-18	1.1e-19
275	1.50e-18	1.1e-19