ENTRY 13813 20010629 00001381300000001 SUBENT 13813001 20010629 00001381300100001 BIB 15 43 1381300100002 INSTITUTE (1USAANL) 1381300100003 REFERENCE (J,NSE,63,55,1977) 1381300100004 AUTHOR (W.M.Wilson, H.E.Jackson, G.E.Thomas) 1381300100005 TITLE A Comparison of the Gamma-Ray Spectra from 2.8-keV 1381300100006 Neutron Capture and Thermal-Neutron Capture in 1381300100007 Sodium-23. 1381300100008 FACILITY (REAC) Reactor CP-5. 1381300100009 INC-SOURCE (REAC) Reactor core with a flux ~3E+13 n.cm**2.s**(-1) 1381300100010 INC-SPECT Reactor spectrum filtered with a boron-10 shield. 1381300100011 SAMPLE 14.6-g sodium sample in zirconium metal container 1381300100012 surrounded by a 0.5-in.-thick layer of 10B. 1381300100013 METHOD Internal-target arrangement used so that the sample 1381300100014 (capture-gamma-ray source) was located in the 1381300100015 high-flux region of a reactor and was viewed (through 1381300100016 a collimator) by a detector located outside of the 1381300100017 reactor. The 2.8-keV resonance was selectively 1381300100018 populated by using the boron-shielded target 1381300100019 technique. 1381300100020 DETECTOR (BPAIR) High-resolution annihilation pair spectrometer.1381300100021 MONITOR The 14N(n,gamma)15N reaction (with nitrogen introduced 1381300100022 in the tube) was used as a calibration standard for 1381300100023 both the relative intensities and the energies. 1381300100024 Absolute intensities obtained by normalization to well-1381300100025 known 2.754-MeV gamma line following the beta decay 1381300100026 of 24Na. 1381300100027 CORRECTION Absolute intensities corrected for self-absorption in 1381300100028 the sodium sample. 1381300100029 ERR-ANALYS (DATA-ERR) Statistical errors given; in the peak areas 1381300100030 these are expected to dominate the systematic errors 1381300100031 and fit errors. 1381300100032 (E-ERR) Estimated systematic uncertainty in gamma-ray 1381300100033 energy; function of the errors in the energies of the 1381300100034 standard nitrogen lines and errors in determining the 1381300100035 centroids of the unknown sodium lines. 1381300100036 ADD-RES The hypothesis that a bound level contributes to the 1381300100037 thermal-neutron capture cross section was tested by 1381300100038 comparing the resonance spectrum with the thermal- 1381300100039 neutron capture gamma-ray spectrum: Departure from 1381300100040 complete correlation between the absolute intensities 1381300100041 of lines in the two spectra was used as a measure of 1381300100042 the contribution of the bound level to the thermal- 1381300100043 capture cross section. 1381300100044 HISTORY (20010626C) IS 1381300100045 ENDBIB 43 0 1381300100046 COMMON 1 3 1381300100047 EN-MEAN 1381300100048 KEV 1381300100049 2.85 1381300100050 ENDCOMMON 3 0 1381300100051 ENDSUBENT 50 0 1381300199999 SUBENT 13813002 20010629 00001381300200001 BIB 2 2 1381300200002 REACTION (11-NA-23(N,G)11-NA-24,,SPC,,SPA) 1381300200003 STATUS Data taken from Table 1 of reference 1381300200004 ENDBIB 2 0 1381300200005 NOCOMMON 0 0 1381300200006 DATA 4 10 1381300200007 E E-ERR DATA DATA-ERR 1381300200008 KEV KEV PC/REAC PC/REAC 1381300200009 6489.4 0.4 1.7 0.2 1381300200010 6398.0 0.3 24.8 0.2 1381300200011 5619.2 0.4 4.0 0.2 1381300200012 5612.7 1.0 0.4 0.2 1381300200013 3984.1 0.3 12.8 0.3 1381300200014 3589.8 0.3 9.0 0.4 1381300200015 3372.2 0.5 3.6 0.4 1381300200016 2754.0 0.3 7.8 1381300200017 2520.3 0.3 10.9 0.3 1381300200018 2210.3 0.5 2.2 0.5 1381300200019 ENDDATA 12 0 1381300200020 ENDSUBENT 19 0 1381300299999 ENDENTRY 2 0 1381399999999