wavelength	cross sect.	uncertainty

270-279		1.31e-20	2.7e-22
280-289		1.80e-20	2.7e-22
290-299		2.31e-20	3.1e-22
300-309		2.31e-20	3.1e-22
310-319		2.59e-20	3.1e-22
320-329		2.06e-20	3.1e-22
330-339		1.23e-20	2.7e-22
340-349		6.65e-21	2.7e-22
350-359		5.77e-21	2.3e-22
360-369		1.34e-21	2.3e-22
370-379		9.94e-22	2.3e-22