wavel.	cross section	error limit

220	2.45e-17	5.3e-18
245	1.24e-17	1.0e-18
250	1.30e-17	2.2e-18
255	1.12e-17	1.8e-18
260	9.20e-18	2.0e-19
270	6.00e-18	7.0e-19
280	3.50e-18	1.2e-18