Spectrometer Experiments

A 1-m normal incidence spectrometer has been installed on CTIX, which permits spectral analysis of plasma emission ranging from visible to vacuum ultraviolet (VUV) wavelengths. The plasma is viewed axially using a quartz window connected to the end of the target chamber and can be viewed transversely via relay optics. With a gated, intensified CCD camera as photon detector, plasma emissions in the 350-900 nm range can be obtained with ~ 0.1 nm wavelength resolution and ~ 100 ns temporal resolution. Surveys of typical CTIX plasmas are being performed over a wide wavelength range, with the objective of identifying bright emission lines for use as plasma temperature and density diagnostics, via line ratios, and plasma velocity, via asymmetric Doppler shift. The example below shows spectra with and without gas puffing in the CTIX accelerator region. Methane puffing has been used to inject controlled quantities of carbon. An enhancement in intensity of the carbon (C II) emission line is clearly observed.



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