  The proposed cyclotron gas-stopping scheme for the efficient thermalization
of intense rare isotope beams is examined. Simulations expand on previous
studies and expose many complications of such an apparatus arising from
physical effects not accounted for properly in previous work. The previously
proposed cyclotron gas-stopper geometry is found to have a near null
efficiency, but extended simulations suggest that a device with a much larger
pole gap could achieve a stopping efficiency approaching roughly 90% and at
least a 10 times larger acceptance. However, some of the advantages that were
incorrectly predicted in previous simulations for high intensity operation of
this device are compromised.
