wavelength	cross sect.	uncertainty

270-279		1.49e-20	3.8e-22
280-289		1.99e-20	3.8e-22
290-299		2.45e-20	3.8e-22
300-309		2.71e-20	3.8e-22
310-319		2.60e-20	3.8e-22
320-329		2.18e-20	3.8e-22
330-339		1.34e-20	3.8e-22
340-349		8.03e-21	3.8e-22
350-359		7.26e-21	3.8e-22
360-369		1.53e-21	3.8e-22
370-379		1.15e-21	3.8e-22