  The principle of the momentum computed tomography of charged particles is
presented. It may be useful for momentum spectroscopy of various beam-matter
interactions, especially when very intense beams are involved. It is able to
collect the shower of charged particles with the 4Pi solid angle, and suitable
for measuring the overall perspective of the arbitrary momentum distribution of
the outgoing charged particles induced by arbitrary beams, especially when the
other techniques are invalid. The extended collisional region, the strong field
approximation and the case without magnetic field are discussed.
