The R&D needs for a neutrino factory, based on a muon storage ring, are pre
sented. Such a neutrino factory consists of several modules. All these modu
les must be developed, namely: intense proton source, pion production targe
t and collection system, ionization cooling, acceleration and storage of th
e muons. R&D on these modules will be discussed in terms of theory and simu
lation, engineering prototypes, and experiments in particle beams. (C) 2001
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