We have built a sputter erosion sensor using Cavity Ring-Down Spectroscopy (CRDS) for validating the numerical analysis tool called "JIEDI tool". In this paper, we measured the velocity distribution function of the aluminum atoms sputtered from an aluminum acceleration grid of the ion thruster. The experimentally obtained aluminum velocity distribution have been found to be compatible with those calculated by the numerical analysis method.

A cavity ring-down spectroscopy method to measure sputter erosion and estimate the lifetime of electric propulsion systems was developed. We measured sputtered aluminum atoms from the acceleration grid of an ion thruster. An external-cavity diode laser was used as the probe laser to measure the aluminum transition line from ground state to upper state, at 394.512 nm (vacuum). The erosion rate of the acceleration grid was estimated to be ng/s.

Vapor-liquid two phase flow behavior of R123 inside herringbone microfin tubes has been studied. Herringbone microfm tube is a kind of internally finned tube in which microfins are installed inside the tube where the microfins form multi-V-shape in flow direction. For the present experiment three different types of herringbone microfin tubes with helix angle fl = 8 °, 14 ° and 28 ° are used. Experimental observations showed how flow diverges and converges inside herringbone microfin tube due to fin arrangement. The effect is more remarkable for larger helix angle. From the measurements of the cross-sectional liquid flow rate distribution, the liquid removal and collection and the entrained droplet are discussed. Quantity of liquid droplets is increased with increase of helix angle. The tube with helix angle fl = 28 ° shows higher quantity of liquid droplets than others.