ENTRY 13814 20010727 00001381400000001
SUBENT 13814001 20010727 00001381400100001
BIB 15 44 1381400100002
INSTITUTE (1USAANL) 1381400100003
REFERENCE (J,NP/A,157,520,1970) 1381400100004
AUTHOR (G.B.Beard, G.E.Thomas) 1381400100005
TITLE Gamma Rays from Thermal Neutron Capture in 28Si, 29Si 1381400100006
and 30Si. 1381400100007
FACILITY (REAC) Reactor CP-5. 1381400100008
INC-SOURCE (REAC) Reactor core with a neutron flux ~3E+13 1381400100009
n/cm**2 s. 1381400100010
INC-SPECT Reactor spectrum. 1381400100011
METHOD Internal-target facility used; target sample placed in 1381400100012
high-flux region of reactor and viewed (through a 1381400100013
collimator) by a detector located outside the reactor.1381400100014
Counting rate kept below 2000/sec to avoid peak 1381400100015
broadening. 1381400100016
DETECTOR (GELI) Ge(Li) detector having an active volume of 1381400100017
4 cm**3 and a resolution width of 6.7 keV for 7-MeV 1381400100018
gamma rays. The neutron flux on the detector was 1381400100019
reduced by collimators with neutron absorbing and 1381400100020
scattering materials (filters). 1381400100021
ANALYSIS A singles spectrum was taken by each sample and a 1381400100022
double escape spectrum was obtained by requiring 1381400100023
coincidence between the Ge(Li) detector signal and 1381400100024
the accompanying annihilation radiation observed with 1381400100025
two NaI(Tl) detectors. 1381400100026
Impurity lines were identified from the known 1381400100027
background of the system as well as by a comparison 1381400100028
with spectra from enriched isotopes. 1381400100029
MONITOR (14-SI-29(N,G)14-SI-30,,SPC,,SPA) Relative intensities 1381400100030
normalized to average of the intensities other 1381400100031
investigators have reported for strong 6744 keV. 1381400100032
Gamma-ray calibration based primarily on the peaks 1381400100033
from the 4945.43 keV transition in carbon. Relative 1381400100034
intensities were obtained by first summing the counts 1381400100035
under the individual peaks and then employing the 1381400100036
relative efficiency curve determined for the Ge(Li) 1381400100037
detector. 1381400100038
CORRECTION Corrected for the various thicknesses of the borated 1381400100039
polyethylene absorber. 1381400100040
ERR-ANALYS (ERR-S) Statistical errors in the peak areas given. 1381400100041
COMMENT The results from the 28Si(n,gamma)29Si reaction agreed 1381400100042
well with those from other investigations using 1381400100043
natural or enriched 28Si as targets. 1381400100044
HISTORY (20010630C) IS 1381400100045
(20010727A) BIB correction. 1381400100046
ENDBIB 44 0 1381400100047
COMMON 1 3 1381400100048
EN-DUMMY 1381400100049
EV 1381400100050
0.0253 1381400100051
ENDCOMMON 3 0 1381400100052
ENDSUBENT 51 0 1381400199999
SUBENT 13814002 20010710 00001381400200001
BIB 4 7 1381400200002
REACTION (14-SI-29(N,G)14-SI-30,,SPC,,SPA) 1381400200003
SAMPLE 150 mg of SiO2 enriched to over 99% in 29Si. 1381400200004
ERR-ANALYS (E-ERR) Uncertainties in gamma-ray energies; do not 1381400200005
include possible systematic errors estimated to 1381400200006
be 0.5 keV maximum at low energies and a maximum of 1381400200007
1.0 keV at high energies. 1381400200008
STATUS Data taken from Table 1 of reference. 1381400200009
ENDBIB 7 0 1381400200010
NOCOMMON 0 0 1381400200011
DATA 5 24 1381400200012
E E-ERR DATA ERR-S ERR-S 1381400200013
KEV KEV PC/REAC PC/REAC PER-CENT 1381400200014
2235.9 0.4 2.1 10. 1381400200015
2678.0 1.0 0.30 10. 1381400200016
3101.2 0.2 0.91 10. 1381400200017
3498.0 0.5 0.13 0.02 1381400200018
3738. 2. 0.05 0.02 1381400200019
3769.3 0.5 0.19 10. 1381400200020
3864.8 0.2 1.2 10. 1381400200021
3966.8 0.5 0.13 10. 1381400200022
4011.3 1.5 0.06 0.01 1381400200023
5127.9 0.8 0.08 0.01 1381400200024
5271.2 0.2 0.84 10. 1381400200025
6662.6 1.0 0.04 0.01 1381400200026
6744.2 0.3 1.33 10. 1381400200027
6821. 2. 0.04 0.01 1381400200028
6839.3 0.3 0.17 10. 1381400200029
7111.1 0.3 0.24 10. 1381400200030
7350.6 1.0 0.021 0.004 1381400200031
8374.5 2.0 0.027 0.007 1381400200032
8900. 2. 0.026 0.005 1381400200033
8954.4 2.0 0.006 0.003 1381400200034
9151.7 2.0 0.008 0.003 1381400200035
9619.6 1.0 0.036 10. 1381400200036
9791.7 1.0 0.041 10. 1381400200037
10608.0 0.4 0.26 10. 1381400200038
ENDDATA 26 0 1381400200039
ENDSUBENT 38 0 1381400299999
SUBENT 13814003 20010710 00001381400300001
BIB 4 7 1381400300002
REACTION (14-SI-30(N,G)14-SI-31,,SPC,,SPA) 1381400300003
SAMPLE 150 mg of SiO(2) enriched to over 99% in 30Si. 1381400300004
ERR-ANALYS (E-ERR) Uncertainties in gamma-ray energies; do not 1381400300005
include possible systematic errors estimated to 1381400300006
be 0.5 keV maximum at low energies and a maximum of 1381400300007
0.8 keV at high energies. 1381400300008
STATUS Data taken from Table 3 of reference. 1381400300009
ENDBIB 7 0 1381400300010
NOCOMMON 0 0 1381400300011
DATA 5 13 1381400300012
E E-ERR DATA ERR-S ERR-S 1381400300013
KEV KEV PC/REAC PC/REAC PER-CENT 1381400300014
753.0 1.0 1.1 0.2 1381400300015
1307. 2. 0.081 10. 1381400300016
1694.8 1.0 0.032 0.008 1381400300017
2206.9 0.6 0.11 0.04 1381400300018
2781.0 0.2 0.77 10. 1381400300019
3055.0 0.4 0.73 10. 1381400300020
3534.0 1.0 0.022 0.005 1381400300021
3630.2 0.3 0.076 10. 1381400300022
4259. 2. 0.004 0.002 1381400300023
4381.5 0.4 0.018 10. 1381400300024
4528.3 0.2 0.13 10. 1381400300025
5873.2 0.5 0.011 0.002 1381400300026
6588.7 0.4 0.018 10. 1381400300027
ENDDATA 15 0 1381400300028
ENDSUBENT 27 0 1381400399999
ENDENTRY 3 0 1381499999999