A High Resolution Echelle Monochromator and Its Application to Ion Temperature Measurement of He Plasma

Abstract
For the measurement of the profile of a spectral line, a high dispersive monochromator with an Echelle grating and 12 channels of photoelectric devices using thin glass sheets to separate the line profile was constructed. The measured resolving power is about 2×105 and the linear dispersion at the image plane is 1.2 mm/Å at 5000Å. This instrument was used to measure the ion temperature of a BSG device by employing the 4686Å line of He II.