ENTRY L0052 20160409 L029L005200000001 SUBENT L0052001 20160409 L029L005200100001 BIB 14 92 L005200100002 INSTITUTE (1USALRL) L005200100003 REFERENCE (J,PR/C,24,849,198109) L005200100004 AUTHOR (D.D.Faul,B.L.Berman,P.Meyer,D.L.Olsen) L005200100005 TITLE Photodisintegration of 3H and 3He L005200100006 FACILITY (LINAC,1USALRL) L005200100007 INC-SOURCE (QMPH,ARAD) Positron annihilation in flight. L005200100008 Energy resolution (FWHM) of the photon beam ranged fromL005200100009 approximately 220 keV at E(gamma) = 5 MeV to 505 keV L005200100010 at E(gamma) = 30 MeV. L005200100011 SAMPLE The gas samples, each with a volume of about 0.5 l, L005200100012 were contained within cylindrical stainless-steel L005200100013 tubes 1 m in length and 2.54 cm in inside diameter L005200100014 with welded end caps which had a window thickness of L005200100015 0.76 mm. The gas samples were contained at pressures L005200100016 such that about six atom-moles of gas were used for L005200100017 each measurement (for the radioactive 3H sample, this L005200100018 amounted to 200000 ci). L005200100019 DETECTOR (BF3) The neutron detector consists of a 61-cm cube of L005200100020 paraffin in which 48 high-pressure BF3 tubes are L005200100021 embedded, in four concentric rings of twelve tubes L005200100022 each. L005200100023 METHOD (EXTB,RINGR) Direct photoneutron detection. L005200100024 Ring-ratio neutron multiplicity measurement. L005200100025 The effective neutron detection system permits direct, L005200100026 separate and simultaneous measurements of the partial L005200100027 cross sections (gamma,n)+(gamma,n+p), (gamma,2n), etc.L005200100028 ANALYSIS After the recorded neutron events were corrected for L005200100029 pileup in the detector, the neutron backgrounds L005200100030 (annihilation target removed) were substracted for L005200100031 both the positron and electron measurements. L005200100032 Because the energy spectrum of the annihilation-plus- L005200100033 Bremsstrahlung radiation differs from that of purely L005200100034 Bremsstrahlung photons, a measured correction was L005200100035 applied to the ion-chamber (beam monitor) response to L005200100036 normalize the electron data to the positron data. L005200100037 The normalized electron data then were substracted fromL005200100038 the positron data, leaving the neutron counts which L005200100039 result only from the annihilation radiation. L005200100040 The measured sample-blank data, normalized to equal L005200100041 photon flux, were substracted from the target data to L005200100042 give the net target results. L005200100043 After a small correction for the neutron multiplicity L005200100044 in each ring, the data were corrected for the energy- L005200100045 dependent efficiency of the neutron detector using theL005200100046 ring-ratio result for each energy. L005200100047 The data were converted to photoneutron cross sections L005200100048 by applying the measured ion-chamber response per L005200100049 photon, the known number of target nuclei in the beam,L005200100050 and a small correction for the photon attenuation in L005200100051 the sample. L005200100052 ERR-ANALYS (ERR-S) Statistical errors L005200100053 (ERR-SYS,8.,15.) Overall systematic uncertainty is L005200100054 estimated to be about 8% at 12 MeV, 12% at 22 MeV, andL005200100055 about 15% at the highest measured energies. L005200100056 CORRECTION Corrections were made for pileup effects and for the L005200100057 drifts of the flux monitor and the neutron detector. L005200100058 COMMENT These reactions include the two-body breakup of 3H and L005200100059 the three-body breakup of both 3H and 3He; these L005200100060 measurements for 3H are the first to span the energy L005200100061 region across the peaks of the cross sections. L005200100062 The results, when compared with each other and with L005200100063 results for the two-body breakup cross section for 3H L005200100064 from the literature, show that: L005200100065 a) the two-body breakup cross sections for 3H and 3H L005200100066 have nearly the same shape, but for 3He it is lowerL005200100067 in magnitude; L005200100068 b) the three-body breakup cross section for 3He is L005200100069 higher in magnitude, broader in the peak region, L005200100070 and also rises less sharply from threshold than L005200100071 that for 3H; L005200100072 c) these differencies between the cross sections for L005200100073 the breakup modes largely compensate in their sum L005200100074 so that the total photon absorption cross section L005200100075 for 3H and 3He are nearly the same in both size L005200100076 and shape at energies near and above their peaks. L005200100077 Theoretical results from the literature disagree with L005200100078 the experimental results to a certain extent over the L005200100079 entire photon-energy region for which the photoneutronL005200100080 cross sections were measured. Sum rule predictions L005200100081 also fail to reproduce the experimental results. TheseL005200100082 discrepancies constitute a challenge to principle of L005200100083 charge symmetry of the nuclear force, but more L005200100084 complete theoretical calculations are needed to L005200100085 ascertain whether these discrepancies can be ascribed L005200100086 entirely to electromagnetic effects. L005200100087 HISTORY (19891207C) L005200100088 (19950406A) BIB Updated L005200100089 (20110726A) OS. REACTION in sub.2 corrected, L005200100090 error analysis and status coding updated, 4-digit L005200100091 years introduced L005200100092 (20160408A) OS. Reaction in sub.2 changed, ERR-ANALYS L005200100093 corrected. L005200100094 ENDBIB 92 0 L005200100095 NOCOMMON 0 0 L005200100096 ENDSUBENT 95 0 L005200199999 SUBENT L0052002 20160409 L029L005200200001 BIB 4 7 L005200200002 REACTION (1-H-3(G,N)1-H-2,,SIG) L005200200003 Threshold of the reaction (gamma,n+p) is 8.5 MeV. L005200200004 SAMPLE 3H gas (18.78 grams) contains 0.5% 2H(2), 0.3% 1H(2), L005200200005 and about 0.3% 3He. L005200200006 STATUS (BERMN) Converted from Berman compilation. L005200200007 HISTORY (20110726A) OS. REACTION corrected L005200200008 (20160408A) Reaction changed to (G,N) L005200200009 ENDBIB 7 0 L005200200010 NOCOMMON 0 0 L005200200011 DATA 3 43 L005200200012 EN DATA ERR-S L005200200013 MEV MB MB L005200200014 6.557 0.16 0.08 L005200200015 6.804 0.20 0.06 L005200200016 7.051 0.21 0.04 L005200200017 7.298 0.29 0.04 L005200200018 7.545 0.39 0.03 L005200200019 7.791 0.37 0.04 L005200200020 8.038 0.46 0.05 L005200200021 8.310 0.50 0.05 L005200200022 8.557 0.59 0.05 L005200200023 8.803 0.59 0.04 L005200200024 9.174 0.62 0.03 L005200200025 9.668 0.76 0.03 L005200200026 10.186 0.73 0.04 L005200200027 10.638 0.82 0.06 L005200200028 11.173 0.78 0.07 L005200200029 11.543 0.84 0.10 L005200200030 11.790 0.82 0.10 L005200200031 12.061 0.95 0.10 L005200200032 12.308 0.89 0.11 L005200200033 12.555 0.96 0.12 L005200200034 12.802 0.77 0.13 L005200200035 13.048 0.86 0.14 L005200200036 13.419 0.71 0.10 L005200200037 13.925 0.76 0.11 L005200200038 14.431 0.68 0.13 L005200200039 14.924 0.71 0.13 L005200200040 15.418 0.73 0.13 L005200200041 15.924 0.61 0.14 L005200200042 16.430 0.69 0.16 L005200200043 16.800 0.85 0.22 L005200200044 17.211 0.90 0.12 L005200200045 17.664 0.74 0.17 L005200200046 18.182 0.66 0.17 L005200200047 18.676 0.66 0.18 L005200200048 19.169 0.66 0.18 L005200200049 19.728 0.71 0.15 L005200200050 20.386 0.80 0.15 L005200200051 20.922 0.67 0.15 L005200200052 21.373 0.89 0.18 L005200200053 21.934 0.63 0.25 L005200200054 22.385 0.56 0.21 L005200200055 22.962 0.90 0.19 L005200200056 23.427 0.69 0.19 L005200200057 ENDDATA 45 0 L005200200058 ENDSUBENT 57 0 L005200299999 SUBENT L0052003 20110831 L016L005200300001 BIB 3 4 L005200300002 REACTION (1-H-3(G,2N)1-H-1,,SIG) L005200300003 SAMPLE 3H gas (18.78 grams) contains 0.5% 2H(2), 0.3% 1H(2), L005200300004 and about 0.3% 3He. L005200300005 STATUS (BERMN) Converted from Berman compilation. L005200300006 ENDBIB 4 0 L005200300007 NOCOMMON 0 0 L005200300008 DATA 3 49 L005200300009 EN DATA ERR-S L005200300010 MEV MB MB L005200300011 6.557 0. 0.01 L005200300012 6.804 0. 0.01 L005200300013 7.051 0. 0.01 L005200300014 7.298 0. 0.01 L005200300015 7.545 0. 0.01 L005200300016 7.791 0.03 0.03 L005200300017 8.038 0. 0.01 L005200300018 8.310 0. 0.01 L005200300019 8.557 0. 0.01 L005200300020 8.803 0.01 0.01 L005200300021 9.174 0.07 0.01 L005200300022 9.668 0.17 0.01 L005200300023 10.186 0.27 0.02 L005200300024 10.638 0.37 0.03 L005200300025 11.173 0.50 0.03 L005200300026 11.543 0.61 0.05 L005200300027 11.790 0.63 0.05 L005200300028 12.061 0.65 0.05 L005200300029 12.308 0.66 0.05 L005200300030 12.555 0.77 0.06 L005200300031 12.802 0.80 0.06 L005200300032 13.048 0.74 0.06 L005200300033 13.419 0.80 0.05 L005200300034 13.925 0.87 0.05 L005200300035 14.431 0.89 0.05 L005200300036 14.924 0.86 0.05 L005200300037 15.418 0.90 0.05 L005200300038 15.924 0.89 0.05 L005200300039 16.430 0.95 0.06 L005200300040 16.800 0.86 0.08 L005200300041 17.211 0.88 0.05 L005200300042 17.664 0.86 0.06 L005200300043 18.182 0.90 0.06 L005200300044 18.676 0.84 0.06 L005200300045 19.169 0.80 0.06 L005200300046 19.728 0.75 0.05 L005200300047 20.386 0.68 0.05 L005200300048 20.922 0.78 0.05 L005200300049 21.373 0.65 0.06 L005200300050 21.934 0.80 0.09 L005200300051 22.385 0.78 0.07 L005200300052 22.962 0.63 0.07 L005200300053 23.427 0.67 0.07 L005200300054 23.933 0.55 0.07 L005200300055 24.426 0.66 0.11 L005200300056 24.878 0.65 0.09 L005200300057 25.561 0.54 0.09 L005200300058 26.425 0.51 0.09 L005200300059 27.418 0.42 0.10 L005200300060 ENDDATA 51 0 L005200300061 ENDSUBENT 60 0 L005200399999 SUBENT L0052004 20110831 L016L005200400001 BIB 3 4 L005200400002 REACTION (1-H-3(G,X)0-NN-1,,SIG) L005200400003 SAMPLE 3H gas (18.78 grams) contains 0.5% 2H(2), 0.3% 1H(2), L005200400004 and about 0.3% 3He. L005200400005 STATUS (BERMN) Converted from Berman compilation. L005200400006 ENDBIB 4 0 L005200400007 NOCOMMON 0 0 L005200400008 DATA 3 43 L005200400009 EN DATA ERR-S L005200400010 MEV MB MB L005200400011 6.557 0.16 0.08 L005200400012 6.804 0.20 0.06 L005200400013 7.051 0.21 0.04 L005200400014 7.298 0.29 0.04 L005200400015 7.545 0.39 0.03 L005200400016 7.791 0.43 0.05 L005200400017 8.038 0.46 0.05 L005200400018 8.310 0.50 0.05 L005200400019 8.557 0.59 0.05 L005200400020 8.803 0.62 0.04 L005200400021 9.174 0.84 0.03 L005200400022 9.668 1.10 0.03 L005200400023 10.186 1.27 0.04 L005200400024 10.638 1.56 0.07 L005200400025 11.173 1.78 0.08 L005200400026 11.543 2.06 0.11 L005200400027 11.790 2.08 0.11 L005200400028 12.061 2.25 0.11 L005200400029 12.308 2.21 0.12 L005200400030 12.555 2.50 0.13 L005200400031 12.802 2.37 0.14 L005200400032 13.048 2.34 0.15 L005200400033 13.419 2.31 0.11 L005200400034 13.925 2.50 0.12 L005200400035 14.431 2.46 0.14 L005200400036 14.924 2.43 0.14 L005200400037 15.418 2.53 0.14 L005200400038 15.924 2.39 0.15 L005200400039 16.430 2.59 0.17 L005200400040 16.800 2.57 0.23 L005200400041 17.211 2.66 0.13 L005200400042 17.664 2.46 0.18 L005200400043 18.182 2.46 0.18 L005200400044 18.676 2.34 0.19 L005200400045 19.169 2.26 0.19 L005200400046 19.728 2.21 0.16 L005200400047 20.386 2.16 0.16 L005200400048 20.922 2.23 0.16 L005200400049 21.373 2.19 0.19 L005200400050 21.934 2.23 0.27 L005200400051 22.385 2.12 0.22 L005200400052 22.962 2.16 0.20 L005200400053 23.427 2.03 0.20 L005200400054 ENDDATA 45 0 L005200400055 ENDSUBENT 54 0 L005200499999 SUBENT L0052005 20110831 L016L005200500001 BIB 4 6 L005200500002 REACTION (2-HE-3(G,N+P)1-H-1,,SIG) L005200500003 Threshold of (gamma,n+p) reaction is 7.7 MeV. L005200500004 SAMPLE 3HE gas (16.89 grams) contains <0.01% 4He and hydrogen L005200500005 isotopes L005200500006 STATUS (BERMN) Converted from Berman compilation. L005200500007 HISTORY (19950406A) REACTION corrected. L005200500008 ENDBIB 6 0 L005200500009 NOCOMMON 0 0 L005200500010 DATA 3 35 L005200500011 EN DATA ERR-S L005200500012 MEV MB MB L005200500013 7.298 0.00 0.02 L005200500014 7.791 0.00 0.02 L005200500015 8.310 0.01 0.02 L005200500016 8.803 0.00 0.03 L005200500017 9.297 0.17 0.03 L005200500018 9.791 0.20 0.05 L005200500019 10.309 0.39 0.05 L005200500020 10.802 0.54 0.04 L005200500021 11.296 0.65 0.03 L005200500022 11.790 0.70 0.02 L005200500023 12.308 0.81 0.03 L005200500024 12.802 0.91 0.04 L005200500025 13.295 0.95 0.05 L005200500026 13.789 0.91 0.04 L005200500027 14.307 0.91 0.06 L005200500028 14.801 0.93 0.04 L005200500029 15.294 0.97 0.05 L005200500030 15.665 0.99 0.03 L005200500031 16.224 0.99 0.03 L005200500032 16.635 1.01 0.03 L005200500033 17.210 1.00 0.03 L005200500034 17.664 1.02 0.04 L005200500035 18.182 1.12 0.04 L005200500036 18.676 1.09 0.05 L005200500037 19.196 1.08 0.04 L005200500038 19.688 0.99 0.04 L005200500039 20.181 1.01 0.05 L005200500040 20.675 1.04 0.06 L005200500041 21.168 1.00 0.06 L005200500042 21.802 0.96 0.04 L005200500043 22.550 0.88 0.05 L005200500044 23.299 0.82 0.05 L005200500045 24.056 0.73 0.05 L005200500046 24.796 0.65 0.05 L005200500047 25.808 0.73 0.04 L005200500048 ENDDATA 37 0 L005200500049 ENDSUBENT 48 0 L005200599999 SUBENT L0052006 20110831 L016L005200600001 BIB 4 6 L005200600002 REACTION (2-HE-3(G,N+P)1-H-1,,INT) L005200600003 Threshold of (gamma,n+p) reaction is 7.7 MeV. L005200600004 FLAG (1.) Extrapolated from the present data. L005200600005 STATUS (TABLE) Data taken from Table 3 of article L005200600006 (DEP,L0052005) L005200600007 HISTORY (19950406A) REACTION corrected. L005200600008 ENDBIB 6 0 L005200600009 NOCOMMON 0 0 L005200600010 DATA 5 4 L005200600011 EN-MIN EN-MAX DATA ERR-S FLAG L005200600012 MEV MEV MB*MEV MB*MEV NO-DIM L005200600013 7.7 23.4 12.3 1.2 L005200600014 7.7 25.8 14.1 1.4 L005200600015 7.7 26.4 14.4 1.4 1. L005200600016 7.7 30. 16.4 2.0 1. L005200600017 ENDDATA 6 0 L005200600018 ENDSUBENT 17 0 L005200699999 SUBENT L0052007 20110831 L016L005200700001 BIB 3 5 L005200700002 REACTION (1-H-3(G,X)0-NN-1,UNW,INT) L005200700003 Threshold of the reaction (gamma,n+p) is 8.5 MeV. L005200700004 FLAG (1.) Extrapolated from the present data. L005200700005 STATUS (TABLE) Data taken from Table 3 of article L005200700006 (DEP,L0052002) L005200700007 ENDBIB 5 0 L005200700008 NOCOMMON 0 0 L005200700009 DATA 5 4 L005200700010 EN-MIN EN-MAX DATA ERR-S FLAG L005200700011 MEV MEV MB*MEV MB*MEV NO-DIM L005200700012 6.3 23.4 11.7 1.2 L005200700013 6.3 25.8 13.2 1.3 1. L005200700014 6.3 26.4 13.6 1.3 1. L005200700015 6.3 30. 15.4 1.8 1. L005200700016 ENDDATA 6 0 L005200700017 ENDSUBENT 16 0 L005200799999 SUBENT L0052008 20110831 L016L005200800001 BIB 3 4 L005200800002 REACTION (1-H-3(G,2N)1-H-1,,INT) L005200800003 FLAG (1.) Extrapolated from the present data. L005200800004 STATUS (TABLE) Data taken from Table 3 of article L005200800005 (DEP,L0052003) L005200800006 ENDBIB 4 0 L005200800007 NOCOMMON 0 0 L005200800008 DATA 5 4 L005200800009 EN-MIN EN-MAX DATA ERR-S FLAG L005200800010 MEV MEV MB*MEV MB*MEV NO-DIM L005200800011 8.5 23.4 10.2 1. L005200800012 8.5 25.8 11.5 1.2 L005200800013 8.5 26.4 12. 1.2 L005200800014 8.5 30. 13.6 1.6 1. L005200800015 ENDDATA 6 0 L005200800016 ENDSUBENT 15 0 L005200899999 ENDENTRY 8 0 L005299999999