1. 20 2000 [15] 02| 18 2500 [14]
2. TimeRelativeto MassTrigger (ms) 0-1000 1500 2000
3. One corner cube isattached to the thrust stand table and the other to the thruster. A 1mW Helium-Neon laser(A=632.8 nm) was used as a light source in the interferometer. Both the beam splitter and the right angle prism were mounted on two adjoined aluminum blocks with separate pitch angle adjustment. Also the beam splitter and right angle prism can each slide sideways to match the horizontal separation ofthe corner cubes. Both oftheseadjustments are made until both beams are nearly coincident at the adjustable mirror. The mirror is then used to direct the beams to the diode sensors. Between the mirror and the diodes are a lens and a filter. The lens is a cylindrical lensoffocal length 1cm. Finallythere is a 3 nm bandwidth filter at wavelength 632.8 nm. This prevents virtually all of the stray light from the surroundings from reaching the diode sensors, including light from the plasma discharge. The diode sensors are FDS100 Silicon Photodiodes from Thorlabs Inc. They have a rise time of 10 ns, an active area of 13.7 mm2, and a spectral response of 350-1100 nm.