  Motivated by the observations of high Faraday rotation measures measured in
cooling flow clusters we propose a model relevant to plasmas with comparable
thermal and magnetic pressures. Magnetic field reconnection may play a major
role in changing the topology of the magnetic field in the central cooling flow
regions. The effect of the topology change is that cool flux loops can
reconnect to hot flux loops that are connected to the overall thermal reservoir
of the cluster. There can be a rapid recycling of mass between hot and cold
phases on a time scale of 3 x 10^8-10^9 yr which may reduce the inferred inflow
and mass condensation rates by at least an order of magnitude. A central
multiphase medium is a direct consequence of such a model. Throughout the
cooling flow the filling factor of the hot loops (T > 2 x 10^7 K) is of order
unity. The filling factor of the cool loops (T < 2 x 10^7 K) is 0.1-1% with a
corresponding mass fraction of cold phase of 1-10%. A crucial parameter is the
coherence length of the field relative to the cooling radius and the
distribution of field energy with scale. When the cooling radius is greater
than the field coherence length then cooling flows proceed as usual. When the
coherence length is greater than the central cooling radius, however, the
thermal energy of the reservoir can be tapped and the mass condensation rates
may be very significantly reduced. Three additional conditions must be
satisfied: I. Cold loops must be able to fall at least as far as the mean
distance between hot loops in a cooling time; II. Loops must enter an
evaporative phase on reconnecting; and III. A sufficient number of hot loops
penetrate the cold phase region to power the radiative losses.
