Edge Localized Modes have been studied in PBX-M discharges with high d
ata sampling rate magnetic diagnostics with good spatial coverage. Hig
h frequency (greater-than-or-equal-to 250 kHz) activity appears prior
to the increase in the D(alpha) emission. While this high frequency ac
tivity is global, with high coherence for all coils both on the inside
and outside midplane, there is no identifiable mode structure. A very
intense outward ballooning feature appears simultaneously with the in
crease in the D(alpha) emission, and lasts for about 5 msec. The toroi
dal mode structure of this feature is clearly identifiable, consisting
of a series of toroidal harmonics from n=3 to 8, at frequencies given
by f(n)=f0+nDELTAf, where DELTAf=20-30 kHz and f0=30-50 kHz. This fea
ture may be caused by the kinetic ballooning mode.