Hi Zilu
Regarding D(gamma,pn) at 100 MeV (or lower) you are correct that the
BLAST acceptance vanishes. The opening angle between the p and n for
approximately symmetric breakup varies roughly linearly with photon
energy from about 161 deg at 100 MeV to 147 deg at 300 MeV. So the
acceptance vanishes near 100 MeV, neglecting curvature in the BLAST
field. The curvature makes things worse, raising the effective photon
energy where the acceptance becomes non-zero, at least for normal field
which covers most of the available data.
John
-- John R. Calarco Dept. of Physics Univ. of New Hampshire Durham, NH 03824 phone: (603)862-2088 FAX: (603)862-2998 email: calarco@unh.edu
This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:31 EST