He II Line 4686 a as Wavelength Standard for Fourier Transform Spectrometer

We report the experimental work for the determination of wavelength standard to validate the measurements of Fourier transform spectrometer. A dc run hollow-cathode discharge with two anodes on either sides of a cathode is designed for the precise measurements of He II lines at 4686 . The Doppler width and ion-drift shift were measured by using each anode alternatively which changes the direction of electric field from 0o to 180o. The stability of He II line has been investigated and comparable precision with respect to previous work has been obtained. Excellent wavelength accuracy with relative uncertainty in line position of the order of 108 is within reach of single point calibration factor.