“…Average weekly usage has been about one-half of total machine time. Fast neutron beams have been produced by several reactions such as 9 Be (He 3 , n), 9 Be (d, n), 9 Be (p, n) and 7 Li (p, n). The external beam system has been modified in a way that targets can be placed at various positions along the beam line to obtain different target to skin distances and desired fields of exposure.…”