Exposure to a 51Cr neutrino source as that used in Gallex will provide
an excellent overall performance test of Borexino, which should collect about
1400 source induced events, with an initial rate of about 35 counts per day.
This will be particularly important if MSW-small-angle turns out to be the
solution of the solar neutrino problem. In addition, if an independent,
accurate calibration is available, one will have an interesting experiment on
neutrino properties: as an example, a neutrino magnetic moment of the order
5⋅10−11μBcould be detected/excluded at the 90\% C.L.Comment: 7 pages, RevTeX, plus 3 postscripts figures, tarred, compresse