ENTRY M0500 20220130 M119M050000000001 SUBENT M0500001 20220130 M119M050000100001 BIB 14 73 M050000100002 TITLE Photoneutron cross sections in N-14. M050000100003 AUTHOR (R.W.Gellie,K.H.Lokan,N.K.Sherman,R.G.Johnson, M050000100004 J.I.Lodge) M050000100005 REFERENCE (J,CJP,50,1689,1972) M050000100006 INSTITUTE (1CANOTC) M050000100007 FACILITY (LINAC,1CANOTC) M050000100008 INC-SOURCE (BRST) M050000100009 SAMPLE The N-14 target consisted of a 4 l metal dewar flask, M050000100010 of inside diameter 4 in. filled with liquid M050000100011 nitrogen. M050000100012 METHOD (TOF) Photoneutron energy distributions were M050000100013 determined at an angle of 90 degrees to the photon M050000100014 beam using conventional time-of-flight system. The M050000100015 photoneutron time-of-flight distributions from the M050000100016 photodisintegration of N-14 were obtained at M050000100017 bremsstrahlung end-point energies increasing in M050000100018 steps of 2 MeV from 15.5 to 29.5 MeV. M050000100019 DETECTOR (SCIN) 10 in. diameter, 1 in. thick cylinder of M050000100020 NE102 plastic scintillator. M050000100021 ANALYSIS (UNFLD) The bremsstrahlung end-point energy was M050000100022 increased in 2 MeV steps from 15.5 to 29.5 MeV. At M050000100023 each energy, photoneutron t-o-f spectra were measured M050000100024 from N-14 and from additional deuterium target. Each M050000100025 such spectrum was converted to a neutron energy M050000100026 distribution. Using the information about photon M050000100027 spectrum these energy distributions were converted M050000100028 into cross section. Since the first excited state in M050000100029 N-13 lies at energy 2.37 MeV there exists an M050000100030 unambiguous region in each spectrum extending back M050000100031 2.37 MeV from the maximum allowed energy, which can M050000100032 only be reached by neutrons leaving the residual M050000100033 N-13 nucleus in its ground state. The ground-state M050000100034 cross section throughout this region is then M050000100035 obtained simply by dividing this portion of the M050000100036 neutron spectrum by corresponding portion of the M050000100037 associated photon spectrum. The photon distributions M050000100038 were obtained by measuring the photoneutron M050000100039 distributions from deuterium - the difference M050000100040 between spectra obtained from geometrically M050000100041 identical targets of heavy and light water. This M050000100042 gave the possibility for a ratio measurement of the M050000100043 90-degrees differential ground-state cross section M050000100044 for the N-14(g,n0)N-13 reaction relative to H-2(g,n) M050000100045 differential cross section (Weissman and Schultz M050000100046 1971). M050000100047 MONITOR (1-H-2(G,N)1-H-1,,DA) M050000100048 CORRECTION Corrections were used for detector dead time (below M050000100049 1%) and detector efficiency. M050000100050 COMMENT Photoneutron distributions from N-14 have been M050000100051 obtained by time-of-flight methods, for M050000100052 bremsstrahlung end-point energies increasing in 2 M050000100053 mev steps from 15.5 to 29.5 MeV. A large part of the M050000100054 neutron yield is associated with the sequential M050000100055 decay of N-14 to C-12, through well-defined M050000100056 intermediate states of C-13, at 7.55, 8.86, and 11.8 M050000100057 MeV, which are unstable against neutron emission. M050000100058 the (g,n0) cross section for neutron emission to the M050000100059 ground state of N-13 is found to agree very closely M050000100060 with the corresponding (g,p0) cross section, M050000100061 implying a high degree of isospin purity for the M050000100062 giant dipole resonance of N-14. It is observed that M050000100063 the decay of the giant resonance proceeds freely M050000100064 through those odd-parity excited states of the A = M050000100065 13 nuclei which are single hole states formed by the M050000100066 removal of a p-shell nucleon from the parent N-14. M050000100067 the integrated cross section for all M050000100068 neutron-producing interactions was also found. M050000100069 HISTORY (19910218C) M050000100070 (20130627A) Corrected by V.Varlamov: ERR-ANALYS, M050000100071 REACTION, STATUS, dates, lowercase. M050000100072 (20220130A) Corrected by V.Varlamov: MONITOR, PART-DET,M050000100073 EN-SEC, STATUS, INT,,BRA -> INT,,BRS in REACTION of M050000100074 SUBENTs 003 and 004, SUBENTs 005-007 added. M050000100075 ENDBIB 73 0 M050000100076 NOCOMMON 0 0 M050000100077 ENDSUBENT 76 0 M050000199999 SUBENT M0500002 20220130 M119M050000200001 BIB 4 9 M050000200002 REACTION (7-N-14(G,N)7-N-13,PAR,DA,,BRS) M050000200003 ERR-ANALYS No information. M050000200004 STATUS (CURVE) Data presented on Fig. 4 M050000200005 of Can.J.Phys.,50(1972)1689. M050000200006 The USA NIST digitizing. M050000200007 HISTORY (20130627A) Corrected by V.Varlamov: BRA -> BRS, M050000200008 ERR-ANALYS. M050000200009 (20220130A) Corrected by V.Varlamov: EN-SEC, REACTION, M050000200010 STATUS. M050000200011 ENDBIB 9 0 M050000200012 COMMON 2 3 M050000200013 E-LVL ANG M050000200014 MEV ADEG M050000200015 0.0 90. M050000200016 ENDCOMMON 3 0 M050000200017 DATA 2 140 M050000200018 EN DATA M050000200019 MEV MU-B/SR M050000200020 12.14 13.91 M050000200021 12.25 16.07 M050000200022 12.37 14.99 M050000200023 12.47 18.24 M050000200024 12.51 21.49 M050000200025 12.62 25.11 M050000200026 12.75 25.83 M050000200027 12.87 25.83 M050000200028 12.97 28.36 M050000200029 13.05 31.61 M050000200030 13.2 28. M050000200031 13.33 24.38 M050000200032 13.38 18.96 M050000200033 13.5 16.07 M050000200034 13.63 11.38 M050000200035 13.67 20.41 M050000200036 13.81 12.82 M050000200037 13.94 7.77 M050000200038 14.11 8.49 M050000200039 14.28 11.02 M050000200040 14.36 15.71 M050000200041 14.51 11.38 M050000200042 14.63 17.16 M050000200043 14.79 19.33 M050000200044 14.96 22.22 M050000200045 15.09 20.41 M050000200046 15.13 28.72 M050000200047 15.26 25.83 M050000200048 15.43 28. M050000200049 15.67 25.83 M050000200050 15.81 22.22 M050000200051 15.93 18.96 M050000200052 16.12 15.71 M050000200053 16.31 14.27 M050000200054 16.49 14.27 M050000200055 16.63 13.55 M050000200056 16.83 13.91 M050000200057 16.98 13.91 M050000200058 17.06 18.6 M050000200059 17.21 20.41 M050000200060 17.3 24.74 M050000200061 17.44 28.72 M050000200062 17.53 33.77 M050000200063 17.66 33.41 M050000200064 17.71 38.38 M050000200065 17.81 41.72 M050000200066 17.96 38.47 M050000200067 18.03 54.73 M050000200068 18.04 63.76 M050000200069 18.22 66.29 M050000200070 18.28 69.18 M050000200071 18.39 73.87 M050000200072 18.4 78.93 M050000200073 18.55 88.32 M050000200074 18.58 95.91 M050000200075 18.71 99.88 M050000200076 18.73 106.7 M050000200077 18.83 110.4 M050000200078 18.85 117.9 M050000200079 18.97 121.9 M050000200080 19.1 118.3 M050000200081 19.18 128.8 M050000200082 19.33 124.4 M050000200083 19.4 134.9 M050000200084 19.52 138.2 M050000200085 19.68 130.9 M050000200086 19.78 141.4 M050000200087 19.97 145.4 M050000200088 20.05 134.9 M050000200089 20.17 141.1 M050000200090 20.26 145. M050000200091 20.35 138.2 M050000200092 20.45 132.8 M050000200093 20.61 124.8 M050000200094 20.67 132. M050000200095 20.83 125.9 M050000200096 20.91 115.8 M050000200097 21.09 116.5 M050000200098 21.3 107.5 M050000200099 21.44 114. M050000200100 21.53 118.7 M050000200101 21.72 120.8 M050000200102 21.91 118.7 M050000200103 22.1 127.7 M050000200104 22.15 139.3 M050000200105 22.23 133.5 M050000200106 22.27 171. M050000200107 22.31 183.7 M050000200108 22.4 176.8 M050000200109 22.47 189.1 M050000200110 22.52 229.6 M050000200111 22.69 231.7 M050000200112 22.78 232.8 M050000200113 22.94 250.1 M050000200114 23.03 239.7 M050000200115 23.21 232.1 M050000200116 23.27 212.2 M050000200117 23.32 202.1 M050000200118 23.4 199.9 M050000200119 23.53 168.5 M050000200120 23.6 195.6 M050000200121 23.74 164.2 M050000200122 23.78 190.5 M050000200123 23.85 173.6 M050000200124 24.03 184.4 M050000200125 24.08 168.2 M050000200126 24.18 180.8 M050000200127 24.27 154.4 M050000200128 24.41 163.8 M050000200129 24.53 152.6 M050000200130 24.6 132.8 M050000200131 24.65 123.7 M050000200132 24.78 125.9 M050000200133 24.84 138.5 M050000200134 24.95 146.5 M050000200135 25.22 107.5 M050000200136 25.31 82.18 M050000200137 25.45 99.16 M050000200138 25.58 105.3 M050000200139 25.75 99.52 M050000200140 25.94 86.88 M050000200141 26.01 81.46 M050000200142 26.06 85.43 M050000200143 26.28 110.4 M050000200144 26.33 80.37 M050000200145 26.49 100.6 M050000200146 26.64 70.26 M050000200147 26.81 72.79 M050000200148 26.94 64.84 M050000200149 27. 77.12 M050000200150 27.15 66.65 M050000200151 27.26 68.09 M050000200152 27.46 69.18 M050000200153 27.58 71.34 M050000200154 27.8 78.93 M050000200155 27.92 59.42 M050000200156 28.2 61.59 M050000200157 28.29 72.07 M050000200158 28.58 45.33 M050000200159 28.69 65.92 M050000200160 ENDDATA 142 0 M050000200161 ENDSUBENT 160 0 M050000299999 SUBENT M0500003 20220130 M119M050000300001 BIB 5 11 M050000300002 REACTION (7-N-14(G,N)7-N-13,PAR,INT/DA,,4PI/BRS) M050000300003 ANALYSIS Total integrated cross section was obtained from the M050000300004 90-degrees differential cross section. M050000300005 ERR-ANALYS No information. M050000300006 STATUS (DEP,M0500002) M050000300007 (TABLE) Data from the text M050000300008 of Can.J.Phys.,50(1972)1689. M050000300009 HISTORY (20130627A) Corrected by V.Varlamov: ERR-ANALYS, M050000300010 STATUS. M050000300011 (20220130A) Corrected by V.Varlamov: EN-SEC, REACTION, M050000300012 INT,,BRA -> INT,,BRS, STATUS. M050000300013 ENDBIB 11 0 M050000300014 COMMON 2 3 M050000300015 E-LVL ANG M050000300016 MEV ADEG M050000300017 0.0 90. M050000300018 ENDCOMMON 3 0 M050000300019 DATA 3 1 M050000300020 EN-MIN EN-MAX DATA M050000300021 MEV MEV MB*MEV M050000300022 10.6 29. 20. M050000300023 ENDDATA 3 0 M050000300024 ENDSUBENT 23 0 M050000399999 SUBENT M0500004 20220130 M119M050000400001 BIB 4 8 M050000400002 REACTION (7-N-14(G,X)0-NN-1,,INT,,BRS) M050000400003 ERR-ANALYS (DATA-ERR) No information on source of uncertainties. M050000400004 STATUS (TABLE) Data from the text M050000400005 of Can.J.Phys.,50(1972)1689. M050000400006 HISTORY (20130627A) Corrected by V.Varlamov: ERR-ANALYS, M050000400007 STATUS. M050000400008 (20220130A) Corrected by V.Varlamov: STATUS, M050000400009 INT,,BRA -> INT,,BRS. M050000400010 ENDBIB 8 0 M050000400011 NOCOMMON 0 0 M050000400012 DATA 4 1 M050000400013 EN-MIN EN-MAX DATA DATA-ERR M050000400014 MEV MEV MB*MEV MB*MEV M050000400015 10.6 29. 80. 5. M050000400016 ENDDATA 3 0 M050000400017 ENDSUBENT 16 0 M050000499999 ENDENTRY 4 0 M050099999999