L. Qu

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Impurity toroidal rotation has been observed in the center of Alcator C-Mod ohmic plasmas from the Doppler shifts of argon and molybdenum x-ray lines. The rotation is highest (~ 6 x 106 cm/s) in the early portion of the discharges, when the loop voltage is highest and the electron density is lowest, and then typically settles to values < 2 x 106 cm/s during(More)
With the advent of lead-free soldering electronic packaging industry, there are growing concerns regarding the problems of voids in lead-free solder joints. Many researchers are eager to understand the growth, evolution and control factors of bubbles. Due to the restrictions in test conditions imposed by high temperature and opacity of soldering, one cannot(More)
The appearance of IMCs on the Sn/Cu interface plays an important role in the joint reliability. Their growth behavior during solidification of multiple reflows was investigated. Compressed air was employed to blow away the residual liquid solder immediately after heating preservation so that the morphology corresponding to heating preservation would remain(More)
As soldering process is a high temperature phenomenon accompanied by surface reaction kinetics, the computational model for solder bubble growth can be a strong arena for describing those aspects which are otherwise difficult to be understood through the experimental methods. In this paper, the growth of gaseous bubbles in the molten tin solder has been(More)
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