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