Solar He II 30.4 nm Pulsation Frequency Spectrum

We have recently found evidence for solar He II 30.4 nm pulsations from a Fourier transform study of CELIAS/SEM 26-34 nm EUV data. We have now calculated the frequency spectrum of the He II 30.4 nm pulsations during selected days in the solar cycle 23. We will present the CELIAS/SEM EUV flux data and the amplitudes, the frequencies and the phases of the pulsations. The frequencies of the observed pulsations are found to be less than the Brunt-Vaissala frequency. Various pulsation parameters obtained during different phases of the solar cycle will be compared.