“…Therefore, the heat source coordinates (r, z, Q) on the near electrode surface are fitted as (r, l 1 /2 + l 3 •r/l 3 , k 1 •e k2•r ), and the heat source at z = 0 is fitted as (r, 0, k 3 •e k4•r ). Where k 1 , k 2 , k 3 , k 4 are the coefficients needed for fitting and are related to time t. At different I p and t, the heat source distribution is fitted by Equation (12).…”