ENTRY 10948 20170613 14321094800000001 SUBENT 10948001 20170613 14321094800100001 BIB 11 37 1094800100002 TITLE Measurement of the 10B/6Li cross section ratio below 1094800100003 1 keV 1094800100004 AUTHOR (J.B.Czirr, A.D.Carlson) 1094800100005 REFERENCE (C,79KNOX,,84,1979) 1094800100006 INSTITUTE (1USANBS) 1094800100007 FACILITY (LINAC,1USANBS) NBS Linac 1094800100008 DETECTOR (GLASD) 6Li glass scintillator, approximately 2% 1094800100009 natural Li by weight. 1094800100010 Thickness was 0.67 mm, two 5-inch phototubes placed at 1094800100011 either end. 1094800100012 (IOCH) 2.54-cm thick parallel plate ionization chamber 1094800100013 containing enriched BF3 at a partial pressure of 1094800100014 18.75 cm Hg. 1094800100015 MONITOR Background measured with Au and Co foils 1094800100016 METHOD Cd and Pb foils used to reduce neutron overlap and 1094800100017 gamma flash. Only central portion of Li detector used 1094800100018 so as to minimize neutron scattering from phototubes 1094800100019 and surrounding structures. 1094800100020 (TOF) 20 m station used 1094800100021 CORRECTION Correction made for 1094800100022 - Self shielding in Li detector (<0.2%) 1094800100023 - Neutron absorption in 10B ionization chamber 1094800100024 (0.5% AT 1 eV) 1094800100025 - Flux attenuation in 10B ionization chamber (uses 1094800100026 ENDF/B-V total cross sections) 1094800100027 - Backgrounds from reactions caused by out-of-time 1094800100028 neutrons and gamma interactions with detectors, 1094800100029 5% at 5 ev and 20% at 130 eV for 6Li, 1094800100030 2% at 5 ev and 5% at 130 eV for 10B. 1094800100031 - Deadtime 1094800100032 STATUS (APRVD) Approved by A.D.Carlson, 1981/07/31. 1094800100033 HISTORY (19810210C) 1094800100034 (19810827A) BIB correction, addition. 1094800100035 (19840427A) BIB corrections, data heading corrected. 1094800100036 (20150330A) On. PRELM deleted. 002 superseded partly. 1094800100037 (20170613A) On. ERR-ANALYS moved to 002. Major 1094800100038 revision in 002. 1094800100039 ENDBIB 37 0 1094800100040 NOCOMMON 0 0 1094800100041 ENDSUBENT 40 0 1094800199999 SUBENT 10948002 20170613 14321094800200001 BIB 4 21 1094800200002 REACTION 1((5-B-10(N,A)3-LI-7,,SIG,,AV)/ 1094800200003 (3-LI-6(N,T)2-HE-4,,SIG,,AV)) 1094800200004 2((5-B-10(N,A)3-LI-7,,SIG,,AV)/ 1094800200005 (3-LI-6(N,T)2-HE-4,,SIG,,AV)) 1094800200006 STATUS (TABLE) Table I of NBS-SP-594, p84 (1980) except for 1094800200007 the partial uncertainties due to background 1094800200008 subtractions which were confirmed by A.D.Carlson 1094800200009 (2017-06-12). 1094800200010 2(SPSDD,10946002) Final data (A.D.Carlson,2015-03-26) 1094800200011 ERR-ANALYS Representative systematic uncertainties: 1094800200012 En (ev) 6Li(%) 10B(%) 1094800200013 1. 0.4 0.1 1094800200014 4.9 0.1 0.1 1094800200015 132. 0.3 0.1 1094800200016 1000. 0.7 0.3 1094800200017 (ERR-S) Statistical uncertainty 1094800200018 (ERR-1) Background subtraction for Li(n,t) 1094800200019 (ERR-2) Background subtraction for B(n,a) 1094800200020 HISTORY (20150326A) On. 6 data points superseded. 1094800200021 (20170613A) On. ERR-ANALYS moved from 001. 1094800200022 ERR-1 and ERR-2 added. 1094800200023 ENDBIB 21 0 1094800200024 NOCOMMON 0 0 1094800200025 DATA 8 17 1094800200026 EN-MIN EN-MAX DATA 1ERR-S 1DATA 2ERR-S 21094800200027 ERR-1 ERR-2 1094800200028 EV EV NO-DIM NO-DIM NO-DIM NO-DIM 1094800200029 PER-CENT PER-CENT 1094800200030 1. 1.25 1.015 0.0016 1094800200031 0.4 0.1 1094800200032 1.25 1.62 1.019 0.0016 1094800200033 0.4 0.1 1094800200034 1.62 2.17 1.016 0.0016 1094800200035 0.3 0.1 1094800200036 2.58 3.23 1.011 0.0020 1094800200037 0.3 0.1 1094800200038 3.23 3.90 1.017 0.0024 1094800200039 0.2 0.1 1094800200040 6.99 9.26 1.008 0.0022 1094800200041 0.1 0.1 1094800200042 9.26 12.84 1.001 0.0021 1094800200043 0.1 0.1 1094800200044 12.84 25.91 1.000 0.0016 1094800200045 0.1 0.1 1094800200046 25.91 30.89 0.993 0.0036 1094800200047 0.1 0.1 1094800200048 30.89 48.51 0.997 0.0024 1094800200049 0.2 0.1 1094800200050 48.51 75.84 0.996 0.0027 1094800200051 0.2 0.1 1094800200052 75.84 92.60 0.999 0.0048 1094800200053 0.2 0.1 1094800200054 177.0 247.2 0.987 0.0042 1094800200055 0.3 0.1 1094800200056 247.2 311.4 0.998 0.0052 1094800200057 0.4 0.1 1094800200058 311.4 409.8 0.986 0.0054 1094800200059 0.4 0.2 1094800200060 409.8 610.3 0.986 0.0044 1094800200061 0.5 0.2 1094800200062 610.3 963.4 0.988 0.0044 1094800200063 0.6 0.3 1094800200064 ENDDATA 38 0 1094800200065 ENDSUBENT 64 0 1094800299999 ENDENTRY 2 0 1094899999999