  We review new Chandra and HST observations of the core collapsed cluster NGC
6397 as a guide to understanding the compact binary (CB) populations in core
collapse globulars. New cataclysmic variables (CVs) and main sequence
chromospherically active binaries (ABs) have been identified, enabling a larger
sample for comparison of the Lx, Fx/Fv and X-ray vs. optical color
distributions. Comparison of the numbers of CBs with Lx >10^31 erg/s in 4 core
collapse vs. 12 King model clusters reveals that the specific frequency Sx
(number of CBs per unit cluster mass) is enhanced in core collapse clusters,
even when normalized for their stellar encounter rate. Although core collapse
is halted by the dynamical heating due to stellar (and binary) interaction with
CBs in the core, we conclude that production of the hardest CBs -- especially
CVs -- is enhanced during core collapse. NGC 6397 has its most luminous CVs
nearest the cluster center, with two newly discovered very low luminosity (old,
quiescent) CVs far from the core. The active binaries as well as neutron star
systems (MSP and qLMXB) surround the central core. The overall CB population
appears to be asymmetric about the cluster center, as in several other core
collapse clusters observed with Chandra, suggesting still poorly-understood
scattering processes.
