Detection of neutron clusters

A new approach to the production and detection of bound neutron clusters is presented. The technique is based on the breakup of beams of very neutron-rich nuclei and the subsequent detection of the recoiling proton in a liquid scintillator. The method has been tested in the breakup of intermediate energy (30--50 MeV/nucleon) ${}^{11}\mathrm{Li},$ ${}^{14}\mathrm{Be},$ and ${}^{15}\mathrm{B}$ beams. Some six events were observed that exhibit the characteristics of a multineutron cluster liberated in the breakup of ${}^{14}\mathrm{Be},$ most probably in the channel ${}^{10}\mathrm{Be}{+}^{4}n.$ The various backgrounds that may mimic such a signal are discussed in detail.