T Targe et ~., Nuclear Instruments 118, 431 (1974). -6 i Monitort out: 0 Target in M means Ml+ M2+ M3 Ao A2 may be two thin counters separated by,..., 1/411 Pb coincidence Neutrons incident on target:N Neutrons transmitted: NT Neutrons interqcting in target: NA Avagordro's Number: Na NT + NA = N Ne-pNaOX(a) NT = pNaOX )(b) NA = N{l - eNT: (AI A2 C) i NA: Al (A2+ C)i - Al {A2+ C)o N: (Al A2C)0 By normalizing NT' NA, and N to M with target in and out, sorting each of 4 sets of data into energy bins, and substituting into (a) and (b) cr may be found in 2 separate ways