wavel.	cross section 	error limit
			(standard deviation)
310	2.38e-21	5.00e-23
315	1.76e-21	1.00e-22
320	1.30e-21	1.20e-22
325	9.60e-22	1.17e-22
330	7.09e-22	1.10e-22
335	5.24e-22	9.90e-23
340	3.87e-22	8.60e-23
345	2.86e-22	7.30e-23
350	2.11e-22	6.10e-23
355	1.56e-22	5.00e-23
360	1.15e-22	4.10e-23