We would like to thank A. Bulgac and N. Sandulescu for useful discussions during the development of the code HFBRAD. This work was supported in part by the Polish Committee for Scientific Research (KBN) under Contract No. 1 P03B 059 27 and by the Foundation for Polish Science (FNP); and by the U.S. Department of Energy under Contract Nos. DE-FG02-96ER40963 (University of Tennessee), DE-AC05-00OR22725 with UT-Battelle, LLC (Oak Ridge National Laboratory), and DE-FG05-87ER40361 (Joint Institute for Heavy Ion Research).