Photoionization resonance profile parameters of the 3s3p1P1two-electron excitation in He I

Abstract

The cross section profile of the 3s3p 1P1 two-electron excitation has been measured in He I. The cross section was assumed to have the form sigma (E)=C(E)+((E-E0)1/2 Gamma a+(1/2 Gamma )2b)/((E-E0)2+(1/2 Gamma )2) where the adjustable parameters a, b, 1/2 Gamma and E0 were determined by a least squares fitting process. The parameter values obtained in the equipment were: a=0.86+or-0.16 cm-1, b=0.27+or-0.13 cm-1, 1/2 Gamma =65.9+or-7.0 meV, E0=69.919+or-0.007 eV. The Fano parameters q and sigma a were determined from a and b and had the values 1.36+or-0.20 and 0.32+or-0.08 cm-1 respectively.