ENTRY G0011 20060729 G014G001100000001 SUBENT G0011001 20060729 G014G001100100001 BIB 15 49 G001100100002 TITLE The Li-7(gamma,n0)Li-6 cross section near threshold G001100100003 AUTHOR (S.Karataglidis,D.Zubanov,P.D.Harty,M.N.Thompson) G001100100004 INSTITUTE (3AULAML) G001100100005 REFERENCE (J,NP/A,501,(1),108,1989) G001100100006 FACILITY (BETAT) 35 MeV betatron at the University of Melbourne G001100100007 INC-SOURCE (BRST) G001100100008 MONITOR the photon dose was measured using a thin-walled G001100100009 transmission ion chamber the response of which was G001100100010 intercalibrated against that of a standard Replica G001100100011 NBS P2 chamber. G001100100012 SAMPLE isotopic enriched lithium metal (99.7% Li-7), 60 g G001100100013 packed in a 10 cm long * 3.8 cm diameter perspex G001100100014 cylinder and 33.3 g in a 4.1 cm long * 4.0 cm diameter G001100100015 aluminium cylinder. G001100100016 DETECTOR (D4PI,BF3) a 4pi-halpern type neutron detector con- G001100100017 sisting of sixteen BF3 proportional gas counters. the G001100100018 tubes were arranged on three concentric rings: two G001100100019 placed next to the beam tube, eight in the middle ring G001100100020 of radius 7.6 cm and six in the outermost ring of G001100100021 radius 13.1 cm. this configuration was chosen to op- G001100100022 timize the detection of low-energy neutrons. G001100100023 The detection efficiency was determined as a function G001100100024 of neutron energy by determining the H-2(gamma,n)P G001100100025 cross section from threshold (2.225 MeV) to 7 MeV G001100100026 as the energy of the emitted neutron is exactly G001100100027 calculable from the photon energy . G001100100028 METHOD (EXTB) yield curves between 7.0 and 9.0 MeV photon- G001100100029 energy were collected in 25 keV intervals. The neutron G001100100030 background, determined by measuring yield curves with G001100100031 an alluminium sample ( photoneutron threshold above G001100100032 measurement range) with the same neutron scattering G001100100033 characteristics, was subtracted from the neutron G001100100034 yields. G001100100035 ANALYSIS (PLA) the cross section was unfolded from the average G001100100036 yield using the Variable-Bin-Penfold-Leiss method de- G001100100037 veloped at this laboratory. an analysis bin of 150 keV G001100100038 was used across the region of resonance. G001100100039 CORRECTION the neutron energy scale was modified to include G001100100040 moderation effects from the lithium sample ( no more G001100100041 than 5%) in determining the yield as function of the G001100100042 photon energy. G001100100043 ERR-ANALYS (DATA-ERR) the errors include statistical uncertaintiesG001100100044 and systematic uncertainties in the dose monitoring G001100100045 system ( about 5%), and in the detection efficiency G001100100046 curve (about 5%). G001100100047 STATUS (TABLE)the data are from private communication G001100100048 corresponding fig. 2 of Nucl.Phys.A501 (1989), p108. G001100100049 HISTORY (19920205C) HW G001100100050 (20060728A) BIB section updated G001100100051 ENDBIB 49 0 G001100100052 NOCOMMON 0 0 G001100100053 ENDSUBENT 52 0 G001100199999 SUBENT G0011002 20060729 G014G001100200001 BIB 1 1 G001100200002 REACTION (3-LI-7(G,N)3-LI-6,,SIG) G001100200003 ENDBIB 1 0 G001100200004 NOCOMMON 0 0 G001100200005 DATA 3 36 G001100200006 EN DATA DATA-ERR G001100200007 MEV MICRO-B MICRO-B G001100200008 7.00 1.8675E-01 1.1288E+0 G001100200009 7.05 1.6919E+00 1.1668E+0 G001100200010 7.10 8.9859E-01 1.1537E+0 G001100200011 7.15 2.2119E+00 2.1770E+0 G001100200012 7.20 -6.6587E-01 2.2179E+0 G001100200013 7.25 6.7836E+01 2.3065E+0 G001100200014 7.30 1.6015E+01 3.0200E+0 G001100200015 7.35 4.3842E+01 3.8544E+0 G001100200016 7.40 7.1005E+01 5.3343E+0 G001100200017 7.45 7.7911E+01 6.7865E+0 G001100200018 7.50 9.3719E+01 8.9759E+0 G001100200019 7.55 7.4688E+01 6.4162E+0 G001100200020 7.60 6.5761E+01 6.1965E+0 G001100200021 7.65 6.5009E+01 6.9313E+0 G001100200022 7.70 4.8861E+01 8.6578E+0 G001100200023 7.75 6.4827E+01 9.5138E+0 G001100200024 7.80 7.1756E+01 1.0367E+1 G001100200025 7.85 6.6607E+01 6.7123E+0 G001100200026 7.90 6.6584E+01 5.3721E+0 G001100200027 7.95 7.1468E+01 5.6377E+0 G001100200028 8.00 6.5719E+01 6.9984E+0 G001100200029 8.05 6.9980E+01 7.6116E+0 G001100200030 8.10 7.2092E+01 8.0508E+0 G001100200031 8.15 8.0115E+01 5.3736E+0 G001100200032 8.20 9.1581E+01 4.3914E+0 G001100200033 8.25 8.9202E+01 4.8354E+0 G001100200034 8.30 1.0561E+02 5.4770E+0 G001100200035 8.35 1.0109E+02 5.7359E+0 G001100200036 8.40 1.0424E+02 5.9361E+0 G001100200037 8.45 1.1579E+02 6.1753E+0 G001100200038 8.50 1.2184E+02 6.4120E+0 G001100200039 8.55 1.1582E+02 6.6790E+0 G001100200040 8.60 1.3660E+02 6.8552E+0 G001100200041 8.65 1.3000E+02 7.2214E+0 G001100200042 8.70 1.3406E+02 6.8414E+0 G001100200043 8.75 1.3016E+02 1.1199E+1 G001100200044 ENDDATA 38 0 G001100200045 ENDSUBENT 44 0 G001100299999 ENDENTRY 2 0 G001199999999