ENTRY 13757 20010927 00001375700000001 SUBENT 13757001 20010927 00001375700100001 BIB 12 37 1375700100002 INSTITUTE (1USANBS) 1375700100003 REFERENCE (C,75WASH,,240,197503) 1375700100004 AUTHOR (I.G.Schroder,E.D.McGarry,G.de Leeuw-Gierts, 1375700100005 S.de Leeuw) 1375700100006 TITLE Angular Anisotropy in the 6Li(n,alpha)3H Reaction at 1375700100007 25 keV 1375700100008 FACILITY (REAC) Iron-filtered beam facility at the NBS reactor. 1375700100009 Well-collimated l-cm-diameter beam with an intensity 1375700100010 of 5E+5 n/(cm**2 s). 1375700100011 INC-SPECT 99% of the beam composed of 25-keV neutrons and the 1375700100012 remaining 1% made up of contaminants at 82, 137 1375700100013 and 270 KeV. No thermal-neutron contaminant found. 1375700100014 SAMPLE 80 microg/cm2 (0.3 microns) of 6LiF with 3-cm2 1375700100015 circular area mounted by evaporation on the front face1375700100016 of the Silicon surface-barrier detector. 1375700100017 DETECTOR Proton-recoil spectrometer used to measure spectrum of 1375700100018 neutron beam. 1375700100019 ANALYSIS After determination of the background, the numbers of 1375700100020 tritons and alphas were estimated for each of the 2pi 1375700100021 measurements and normalized to the average number of 1375700100022 particles observed in the forward and backward 1375700100023 distributions. This was done under the assumption 1375700100024 that, to the first approximation, tritons and alphas 1375700100025 are emitted in opposite directions in the laboratory 1375700100026 system. 1375700100027 From the number of tritons and alphas emitted in each 1375700100028 of the experimental conditions were determined the 1375700100029 degree of asymmetry involved in each case: 1375700100030 forward-to-backward 0 deg and 45 deg 2pi asymmetry, 1375700100031 forward-to-backward 0 deg ~0.6pi (45 deg cone) 1375700100032 asymmetry, defined as the ratio of the number of 1375700100033 tritons in this directions. 1375700100034 ADD-RES From the experimental results a coarse-grided angular 1375700100035 distribution obtaibed and presented in graphical form 1375700100036 for both the lab and the center-of-mass system. 1375700100037 STATUS Data taken from Table I of reference. 1375700100038 HISTORY (20010917C) IS 1375700100039 ENDBIB 37 0 1375700100040 COMMON 3 3 1375700100041 EN ANG-NM ANG-DN 1375700100042 KEV ADEG ADEG 1375700100043 25. 0. 180. 1375700100044 ENDCOMMON 3 0 1375700100045 ENDSUBENT 44 0 1375700199999 SUBENT 13757002 20010927 00001375700200001 BIB 6 15 1375700200002 REACTION ((3-LI-6(N,T)2-HE-4,,DA)//(3-LI-6(N,T)2-HE-4,,DA)) 1375700200003 DETECTOR (SOLST) Silicon surface-barrier 2 pi detector, mounted 1375700200004 on a pyrofilite (non-hydrogenous) ring, coated on 1375700200005 front face (by evaporation) with sample of 6LiF, and 1375700200006 enclosed in aluminum holder with thin (0.25 mm) front 1375700200007 and back windows to minimize neutron scattering. 1375700200008 METHOD Four series of runs performed and pulse-height 1375700200009 distributions of both 3H and 4He recorded. 1375700200010 CORRECTION Background subtracted. 1375700200011 ERR-ANALYS (DATA-ERR) Absolute uncertainties arising from 1375700200012 estimation of the background (main source) and from 1375700200013 counting statistics. 1375700200014 ADD-RES The backward-to-forward ratio with the front and back 1375700200015 faces at 45 degrees to beam was measured as 1375700200016 1.39+-0.11. 1375700200017 ENDBIB 15 0 1375700200018 NOCOMMON 0 0 1375700200019 DATA 2 1 1375700200020 DATA DATA-ERR 1375700200021 NO-DIM NO-DIM 1375700200022 1.67 0.11 1375700200023 ENDDATA 3 0 1375700200024 ENDSUBENT 23 0 1375700299999 SUBENT 13757003 20010927 00001375700300001 BIB 5 14 1375700300002 REACTION ((3-LI-6(N,T)2-HE-4,,DA)//(3-LI-6(N,T)2-HE-4,,DA)) 1375700300003 DETECTOR (SOLST) Commercial, partially-depleted, surface-barrier1375700300004 detector (D2) with an active area of 200 mm2 and with 1375700300005 an alpha (5.5 MeV) resolution of 19 keV (FWHM), 1375700300006 placed coaxially with the 6Li detector (at 90 deg to 1375700300007 the beam) and in such a way as to subtend a 45 cone 1375700300008 for the products detected. 1375700300009 METHOD (COINC) Coincidence measurements, yielded number of 1375700300010 forward and backward emitted products. 1375700300011 CORRECTION Contribution from small peaks due to thermal-neutron 1375700300012 contamination was subtracted. 1375700300013 ERR-ANALYS (DATA-ERR) Absolute uncertainties, arising from 1375700300014 subtraction of small peaks and from counting 1375700300015 statistics. 1375700300016 ENDBIB 14 0 1375700300017 NOCOMMON 0 0 1375700300018 DATA 3 1 1375700300019 ANG-RSL DATA DATA-ERR 1375700300020 ADEG NO-DIM NO-DIM 1375700300021 45. 1.96 0.11 1375700300022 ENDDATA 3 0 1375700300023 ENDSUBENT 22 0 1375700399999 ENDENTRY 3 0 1375799999999