ENTRY M0322 20071109 M044M032200000001 SUBENT M0322001 20071109 M044M032200100001 BIB 16 37 M032200100002 TITLE Energy and angular distributions of photoneutrons M032200100003 from Oxygen-18. M032200100004 AUTHOR (S.F.MUGHABGHAB,W.E.STEPHENS) M032200100005 INSTITUTE (1USAPEN) M032200100006 REFERENCE (J,PR,133,(3),B660,1964) M032200100007 REL-REF (N,,M.E.TOMS+,J,PR,92,362,1953). Detail description M032200100008 of the experimental technique. M032200100009 FACILITY (BETAT,1USAPEN) M032200100010 INC-SOURCE (BRST) M032200100011 SAMPLE 3 grams of water enriched to 90% in O-18. M032200100012 METHOD (REC) M032200100013 PART-DET (P) M032200100014 DETECTOR (PLATE). 200 mu Ilford K2 emulsions. M032200100015 ADD-RES (THEO,COMP) Theoretical angular distributions have M032200100016 been calculated on the basis of the resonance theory M032200100017 of the compound nucleus. M032200100018 CORRECTION The background was subtracted but had negligible M032200100019 effect on the distribution. M032200100020 COMMENT Distinct peaks in the neutron spectrum at 1.3, 3.1, M032200100021 7.4, and possibly at 1.7, 5.5, 9.2, and 10.5 MeV are M032200100022 observed. The peaks at 1.3 and 3.1 MeV can be M032200100023 accounted for in terms of single-particle excitation M032200100024 modes (2s1/2->2p3/2,1/2) of a valence neutron M032200100025 without disturbing the O-16 core. These correspond M032200100026 to 1-levels in O-16 at 10.3 and 12.2 MeV with M032200100027 transitions leaving O-17 in the 1/2+ excited state M032200100028 at 0.871 MeV. M032200100029 The angular distribution of the neutron is M032200100030 predominantly sin**2 at low energies. At high M032200100031 energies, there is an interference effects between M032200100032 electric dipole and quadrupole absorption. M032200100033 STATUS (CURVE) M032200100034 HISTORY (19850420C) Data were compiled at SCJAD of Saratov M032200100035 State University. M032200100036 (19910202A) Corrected by V.Varlamov, V.Mclane M032200100037 (20071005A) Corrected by V.Varlamov: REFERENCE, dates, M032200100038 lowercase, REACTIONs, COMMENTs. M032200100039 ENDBIB 37 0 M032200100040 NOCOMMON 0 0 M032200100041 ENDSUBENT 40 0 M032200199999 SUBENT M0322002 20071109 M044M032200200001 BIB 4 6 M032200200002 REACTION (8-O-18(G,N)8-O-17,,DA/DE,,BRA/REL) M032200200003 ANALYSIS The number of neutrons was deduced from proton M032200200004 recoils. M032200200005 ERR-ANALYS (E-ERR) Half of range of experimental histogram. M032200200006 FLAG (1.) Indicate distinct peaks in the neutron spectrum. M032200200007 (2.) Indicate further possible peaks. M032200200008 ENDBIB 6 0 M032200200009 COMMON 4 3 M032200200010 ANG-MIN ANG-MAX E-ERR EN-MAX M032200200011 ADEG ADEG MEV MEV M032200200012 30. 150. 0.1 20. M032200200013 ENDCOMMON 3 0 M032200200014 DATA 3 49 M032200200015 E DATA FLAG M032200200016 MEV ARB-UNITS NO-DIM M032200200017 0.8 261. M032200200018 1.0 157. M032200200019 1.2 207. M032200200020 1.4 214. 1. M032200200021 1.6 135. M032200200022 1.8 160. 2. M032200200023 2.0 118. M032200200024 2.2 100. M032200200025 2.4 80. M032200200026 2.6 65. M032200200027 2.8 58. M032200200028 3.0 64. M032200200029 3.2 67. 1. M032200200030 3.4 40. M032200200031 3.6 45. M032200200032 3.8 34. M032200200033 4.0 31. M032200200034 4.2 20. M032200200035 4.4 27. M032200200036 4.6 27. M032200200037 4.8 25. M032200200038 5.0 15. M032200200039 5.2 21. M032200200040 5.4 34. 2. M032200200041 5.6 20. M032200200042 5.8 0. M032200200043 6.0 15. M032200200044 6.2 11. M032200200045 6.4 11. M032200200046 6.6 10. M032200200047 6.8 5. M032200200048 7.0 2. M032200200049 7.2 12. M032200200050 7.4 20. 1. M032200200051 7.6 8. M032200200052 7.8 4. M032200200053 8.0 5. M032200200054 8.2 5. M032200200055 8.4 1. M032200200056 8.6 1. M032200200057 8.8 2. M032200200058 9.0 3. M032200200059 9.2 3. M032200200060 9.4 5. 2. M032200200061 9.6 2. M032200200062 9.8 0. M032200200063 10.0 0. M032200200064 10.2 0. M032200200065 10.4 2. 2. M032200200066 ENDDATA 51 0 M032200200067 ENDSUBENT 66 0 M032200299999 SUBENT M0322003 20071109 M044M032200300001 BIB 6 11 M032200300002 REACTION (8-O-18(G,N)8-O-17,PAR,SIG,,BRS) M032200300003 ANALYSIS Cross section was derived from energy spectrum using M032200300004 the (n,p) scattering cross section and the Schiff M032200300005 bremsstrahlung spectrum. M032200300006 ASSUMED The assumption of transitions to the first excited M032200300007 state of O-17 was made. M032200300008 EN-SEC (E-EXC,8-O-17) Excitation energy after emission of M032200300009 the neutron (1/2+ state). M032200300010 ERR-ANALYS (EN-ERR) Half of range of experimental histogram. M032200300011 (ERR-S) Statistical errors of measurement. M032200300012 STATUS (DEP,M0322002) M032200300013 ENDBIB 11 0 M032200300014 COMMON 1 3 M032200300015 E-EXC M032200300016 MEV M032200300017 0.871 M032200300018 ENDCOMMON 3 0 M032200300019 DATA 4 45 M032200300020 EN EN-ERR DATA ERR-S M032200300021 MEV MEV MB MB M032200300022 9.77 0.10 11.2 0.9 M032200300023 9.98 0.11 7.4 0.7 M032200300024 10.19 0.10 11.5 0.9 M032200300025 10.40 0.11 10.3 1.0 M032200300026 10.61 0.10 9.7 0.9 M032200300027 10.83 0.11 12.7 1.0 M032200300028 11.04 0.10 10.2 0.9 M032200300029 11.25 0.11 9.1 0.9 M032200300030 11.46 0.10 7.7 0.9 M032200300031 11.67 0.11 6.7 0.9 M032200300032 11.88 0.10 6.4 0.9 M032200300033 12.10 0.11 7.8 1.9 M032200300034 12.31 0.10 8.9 1.1 M032200300035 12.52 0.11 5.3 1.1 M032200300036 12.73 0.10 5.7 1.1 M032200300037 13.05 0.21 5.2 1.1 M032200300038 13.37 0.11 3.9 0.9 M032200300039 13.58 0.10 5.2 1.1 M032200300040 13.79 0.11 6.4 1.1 M032200300041 14.00 0.10 6.0 1.1 M032200300042 14.21 0.11 3.9 1.1 M032200300043 14.43 0.10 5.6 1.2 M032200300044 14.64 0.11 9.4 1.5 M032200300045 14.85 0.10 5.3 1.2 M032200300046 15.06 0.11 6.3 1.4 M032200300047 15.27 0.10 3.2 1.3 M032200300048 15.48 0.11 4.6 1.3 M032200300049 15.70 0.10 4.1 1.3 M032200300050 15.91 0.11 3.7 1.2 M032200300051 16.12 0.10 2.2 0.8 M032200300052 16.33 0.11 1.2 0.6 M032200300053 16.54 0.10 5.6 1.7 M032200300054 16.76 0.11 10.9 2.5 M032200300055 16.97 0.10 4.8 1.8 M032200300056 17.18 0.11 3.4 1.4 M032200300057 17.39 0.10 4.4 1.8 M032200300058 17.60 0.11 4.1 1.8 M032200300059 17.92 0.21 0.8 0.8 M032200300060 18.24 0.11 2.0 2.0 M032200300061 18.45 0.10 3.6 1.6 M032200300062 18.66 0.11 9.4 3.1 M032200300063 18.87 0.10 3.0 2.0 M032200300064 19.08 0.11 3.5 2.5 M032200300065 19.50 0.32 0.0 M032200300066 19.92 0.10 7.2 5.0 M032200300067 ENDDATA 47 0 M032200300068 ENDSUBENT 67 0 M032200399999 SUBENT M0322004 20071109 M044M032200400001 BIB 3 4 M032200400002 REACTION (8-O-18(G,N)8-O-17,,DA/DE,,BRA/REL) M032200400003 COMMENT The neutron group at 1.3 MeV shows a strong sin**2 M032200400004 distribution. M032200400005 ERR-ANALYS (ERR-S) Statistical errors are presented. M032200400006 ENDBIB 4 0 M032200400007 COMMON 2 3 M032200400008 E EN-MAX M032200400009 MEV MEV M032200400010 1.3 20. M032200400011 ENDCOMMON 3 0 M032200400012 DATA 3 6 M032200400013 ANG DATA ERR-S M032200400014 ADEG ARB-UNITS ARB-UNITS M032200400015 30. 0.964 0.241 M032200400016 50. 1.639 0.251 M032200400017 70. 2.506 0.241 M032200400018 90. 2.337 0.265 M032200400019 110. 1.735 0.299 M032200400020 130. 1.205 0.265 M032200400021 ENDDATA 8 0 M032200400022 ENDSUBENT 21 0 M032200499999 SUBENT M0322005 20071109 M044M032200500001 BIB 3 4 M032200500002 REACTION (8-O-18(G,N)8-O-17,,DA/DE,,BRA/REL) M032200500003 COMMENT The neutron group at 3.1 MeV shows a strong sin**2 M032200500004 distribution. M032200500005 ERR-ANALYS (ERR-S) Statistical errors are presented. M032200500006 ENDBIB 4 0 M032200500007 COMMON 2 3 M032200500008 E EN-MAX M032200500009 MEV MEV M032200500010 3.1 20. M032200500011 ENDCOMMON 3 0 M032200500012 DATA 3 6 M032200500013 ANG DATA ERR-S M032200500014 ADEG ARB-UNITS ARB-UNITS M032200500015 30. 0.967 0.198 M032200500016 50. 1.788 0.212 M032200500017 70. 2.259 0.203 M032200500018 90. 2.847 0.212 M032200500019 110. 2.047 0.212 M032200500020 130. 0.988 0.235 M032200500021 ENDDATA 8 0 M032200500022 ENDSUBENT 21 0 M032200599999 SUBENT M0322006 20071109 M044M032200600001 BIB 3 5 M032200600002 REACTION (8-O-18(G,N)8-O-17,,DA/DE,,BRA/REL) M032200600003 COMMENT Analitical expression of the experimental angular M032200600004 distribution is a+b*(sin**2)*(1+0.5*cos)**2, where M032200600005 a/b=0.03+-0.01 M032200600006 ERR-ANALYS (ERR-S) Statistical errors are presented. M032200600007 ENDBIB 5 0 M032200600008 COMMON 2 3 M032200600009 E EN-MAX M032200600010 MEV MEV M032200600011 7.4 20. M032200600012 ENDCOMMON 3 0 M032200600013 DATA 3 6 M032200600014 ANG DATA ERR-S M032200600015 ADEG ARB-UNITS ARB-UNITS M032200600016 30. 0.810 0.262 M032200600017 50. 1.429 0.600 M032200600018 70. 2.952 0.786 M032200600019 90. 0.929 0.533 M032200600020 110. 1.881 0.524 M032200600021 130. 0.714 0.333 M032200600022 ENDDATA 8 0 M032200600023 ENDSUBENT 22 0 M032200699999 ENDENTRY 6 0 M032299999999