  We report Chandra observations of the complete sample of millisecond pulsars
(MSPs) with precise radio positions in the globular clusters 47Tuc (NGC104) and
NGC6397. The 47Tuc MSPs are predominantly soft sources suggestive of thermal
emission from small (r_x < 0.6km) polar caps on the neutron star rather than
magnetospheric emission and are a relatively homogeneous sample, with most
x-ray luminosities in a surprisingly narrow range (Lx ~1-4 X 10^30 erg/s). We
use previously derived intrinsic Pdot values and find a new relation between Lx
and spindown luminosity, Edot: Lx ~ Edot^beta, with beta ~0.5 vs. ~1.0 for both
pulsars and MSPs in the field. This Lx-Edot relation and also the Lx/Edot vs.
spindown age are each similar to that found by Harding & Muslimov (2002) for
thermal emission from polar cap heating although the cluster MSPs are
relatively longer-lived (in thermal x-rays) than either the models or field
MSPs. We suggest the cluster MSPs may have altered surface magnetic field
topology (e.g.multipole) or their neutron stars are more massive from repeated
accretion episodes due to encounters and repeated exchange interactions. MSP
binary companions on or just off the main sequence are likely to have been
re-exchanged and might show anomalous Pdot and Edot values due to relaxation of
misaligned core-crust spins. The radial distribution of 40 soft Chandra sources
in 47Tuc is consistent with a 1.4Msun component. The implied total MSP
population in 47Tuc with Lx >10^30 erg/s is ~35-90, and can constrain the
relative beaming in radio vs. soft x-rays. NGC6397 is relatively deficient in
MSPs; its single detected example may have been re-exchanged out of the cluster
core. (abridged)
