Scaling of Type-I ELM Divertor Energy, Heat Flux, and Profile Width in DIII-D

In this paper, we show scaling of divertor plate energy per ELM, peak heat flux and heat flux profile width of Type-I ELMs in DIII-D. We obtained data using an IR camera that viewed the divertor during discharges with large low-frequency ELMs. We independently varied the input power $P_{in}$, line-averaged density $\bar n_e$, and toroidal field $B_T$ at constant $q_{95}$, with other parameters (nearly) fixed. We also scanned $I_p$ while allowing the natural $\bar n_e$ (i.e., no gas puffing during the H-mode), with other quantities fixed. Previous scaling efforts have examined the pedestal energy loss during ELMs. We compare the deposited divertor energy with those analyses. We examine the fraction of total ELM energy reaching the target, the variation of ELM heat flux rise time, and the fraction of ELM energy deposited before the surface temperature peak. \vskip6pt \noindent [1] A.W. Leonard et al., Plasma Phys. Control. Fusion {\bf 44}, 945 (2002). \noindent [2] A. Loarte et al., J. Nucl. Mater. {\bf 313-316}, 962 (2003).