ENTRY 23110 20100923 22232311000000001 SUBENT 23110001 20100923 22232311000100001 BIB 15 87 2311000100002 TITLE A facility for measurement of (n,gamma) cross-section 2311000100003 of a nucleus in the range 0.008 <= En <20 MeV. 2311000100004 AUTHOR (M.Segawa,Y.Toh, H.Harada,F.Kitatani, M.Koizumi, 2311000100005 Y.Hatsukawa, T.Fukahori, H.Matsue, M.Oshima,Y.Tanumura,2311000100006 Y.Nagai) 2311000100007 INSTITUTE (2JPNJAE) M.Segawa,Y.Toh, H.Harada,F.Kitatani,M.Koizumi2311000100008 Y.Hatsukawa, T.Fukahori, H.Matsue, M.Oshima,Y.Tanumura,2311000100009 Y.Nagai . 2311000100010 (2JPNOSA) Y.Nagai 2311000100011 REFERENCE (J,NIM/A,618,153,2010) 2311000100012 Main reference. 2311000100013 FACILITY (VDG,2JPNJAE) 4 MV Pelletron accelerator 4UH-HC, 2311000100014 equipped with Duoplasmatron ion source. 2311000100015 INC-SOURCE (P-LI7) Li-7(p,n)Be-7. 2311000100016 Proton beam energy was calibrated using the 2311000100017 Li-7(p,n)Be-7 reaction at the threshold energy within 2311000100018 uncertainty of 1 keV. Typical average proton beam 2311000100019 current about 5 microA, repetition rate 4 MHz, pulse 2311000100020 width 3.3 nsec (FWHM). 2311000100021 Li-7 neutron production target of thickness about 2311000100022 100 mg/cm**2 was made by evaporating lithium fluoride 2311000100023 on copper disk with thickness of 0.5 mm. 2311000100024 INC-SPECT Quasi-monoenergetic pulsed neutrons. 2311000100025 12<= En <=103 keV. 2311000100026 Typical neutron energy spectrum obtained by blank 2311000100027 sample is shown on Fig. 2 . 2311000100028 DETECTOR (SPEC,NAICR) Anti-Compton NaI(Tl) spectrometer to 2311000100029 detect discrete gamma-rays promptly emitted from the 2311000100030 neutron-capture of a nucleus. 2311000100031 Spectrometer consisted of a central NaI(Tl) detector 2311000100032 of 22.9 cm diameter and 20.3 cm length and annular 2311000100033 NaI(Tl) detector of 33.0 cm diameter, 27.9 cm length. 2311000100034 Low-background photomultiplier tubes - to reduce 2311000100035 background due to the gamma-rays from beta-decay of 2311000100036 K-40 (at 1.461 MeV). 2311000100037 Spectrometer was shielded with Li-6-H (30cm thickness)2311000100038 and borated polyethylene to prevent neutrons scattered2311000100039 by sample and Pb against gamma-rays produced by 2311000100040 thermalized neutron-capture reactions by materials 2311000100041 placed in the measurement room. 2311000100042 Energy resolution of the central NaI(Tl) detector was 2311000100043 7% at 662 keV. 2311000100044 Spectrometer was set at 100 degrees with respect to 2311000100045 the proton beam direction. 2311000100046 The distance between sample position and the front 2311000100047 face of the central NaI(Tl) detector was 119 cm. 2311000100048 Energy calibration of the central NaI(Tl) detector was2311000100049 made using gamma-ray standard sources- Na-22, Co-60, 2311000100050 Y-88, and gamma-rays from H-1(n,gamma)H-2 and 2311000100051 Fe-56(n,g)Fe-57 reactions. 2311000100052 (GLASD) Li-6-glass scintillation detector with diameter2311000100053 of 50mm, thickness of 12 mm -to measure TOF neutron 2311000100054 spectrum. Placed 30 cm downward from the Li-7 neutron 2311000100055 production target. 2311000100056 Energy resolution of system 2.6%(FWHM) at 6.1 MeV. 2311000100057 SAMPLE Natural lead sample of 90 mm diameter, 8 mm thickness.2311000100058 Gold sample of 90 mm diameter, 2mm thickness - for 2311000100059 normalization. 2311000100060 Pb-nat and Au samples were placed 12.7 cm downward from2311000100061 Li-7(LiF) neutron production target. 2311000100062 Pb sample abundances: Pb-204 - 0.0138+-0.0003, 2311000100063 Pb-206 - 0.2479+-0.0020, Pb-207 - 0.2150+-0.0016, 2311000100064 Pb-208 - 0.5233+-0.0041 . 2311000100065 METHOD (TOF) Flight path 12.7 cm. 2311000100066 Corresponding resolution in neutron energy is 4.2 keV 2311000100067 at 30 keV. 2311000100068 TOF spectrum of neutrons produced by 2311000100069 Li-7(p,n)Be-7 reaction was measured by the efficiency 2311000100070 calibrated . 2311000100071 (TRN) Neutron transmission of gold and Pb-nat was 2311000100072 measured. 2311000100073 MONITOR (79-AU-197(N,G)79-AU-198,,SIG) 2311000100074 MONIT-REF (,P.G.Young+,3,ENDF/B-VI,,1984) 2311000100075 CORRECTION -For overestimation of the gamma-ray yield due to the 2311000100076 multiple-scattering effect and the shielding of the 2311000100077 incident neutrons in sample - calculated using the 2311000100078 Monte-Carlo code, TIME-MULTI. 2311000100079 -For the gamma-ray absorption by the sample. 2311000100080 -For the finite size of the sample. 2311000100081 -Background subtraction. 2311000100082 ERR-ANALYS (ERR-T) uncertainty is the result of the combined 2311000100083 uncertainties on : 2311000100084 (ERR-S,2.,5.) Uncertainty of statistics of gamma-ray 2311000100085 yield(2-5%); 2311000100086 (MONIT-ERR) Uncertainty of the absolute cross-section 2311000100087 of Au. 2311000100088 HISTORY (20100929C) M.M. 2311000100089 ENDBIB 87 0 2311000100090 COMMON 1 3 2311000100091 MONIT-ERR 2311000100092 PER-CENT 2311000100093 3. 2311000100094 ENDCOMMON 3 0 2311000100095 ENDSUBENT 94 0 2311000199999 SUBENT 23110002 20100929 22232311000200001 BIB 3 4 2311000200002 REACTION (82-PB-0(N,G),,SIG,,AV) 2311000200003 Neutron capture cross-section. 2311000200004 MISC-COL (MISC) Total correction factor. 2311000200005 STATUS (TABLE) Table 2 of J,NIM/A,618,153,2010 2311000200006 ENDBIB 4 0 2311000200007 NOCOMMON 0 0 2311000200008 DATA 6 3 2311000200009 EN-MIN EN-MAX EN-MEAN DATA ERR-T MISC 2311000200010 KEV KEV KEV MB MB NO-DIM 2311000200011 12. 30. 20. 13.8 0.8 1.63 2311000200012 30. 50. 41. 17.9 0.7 1.23 2311000200013 50. 103. 74. 6.2 0.3 1.17 2311000200014 ENDDATA 5 0 2311000200015 ENDSUBENT 14 0 2311000299999 SUBENT 23110003 20100929 22232311000300001 BIB 3 4 2311000300002 REACTION (82-PB-206(N,G)82-PB-207,PAR,SIG,,A/AV) 2311000300003 Partial neutron capture cross-section. 2311000300004 EN-SEC (E,G) 2311000300005 STATUS (TABLE) Table 2 of J,NIM/A,618,153,2010 2311000300006 ENDBIB 4 0 2311000300007 NOCOMMON 0 0 2311000300008 DATA 6 9 2311000300009 EN-MIN EN-MAX EN-MEAN E DATA ERR-T 2311000300010 KEV KEV KEV MEV MB MB 2311000300011 12. 30. 20. 6.76 5.2 0.6 2311000300012 12. 30. 20. 6.19 3.4 0.4 2311000300013 12. 30. 20. 5.86 2.9 0.4 2311000300014 30. 50. 41. 6.78 5.0 0.3 2311000300015 30. 50. 41. 6.21 1.3 0.2 2311000300016 30. 50. 41. 5.88 3.0 0.2 2311000300017 50. 103. 74. 6.81 1.6 0.2 2311000300018 50. 103. 74. 6.24 0.6 0.1 2311000300019 50. 103. 74. 5.91 2.3 0.2 2311000300020 ENDDATA 11 0 2311000300021 ENDSUBENT 20 0 2311000399999 SUBENT 23110004 20100929 22232311000400001 BIB 3 4 2311000400002 REACTION (82-PB-207(N,G)82-PB-208,PAR,SIG,,A/AV) 2311000400003 Partial neutron capture cross-section. 2311000400004 EN-SEC (E,G) 2311000400005 STATUS (TABLE) Table 2 of J,NIM/A,618,153,2010 2311000400006 ENDBIB 4 0 2311000400007 NOCOMMON 0 0 2311000400008 DATA 6 6 2311000400009 EN-MIN EN-MAX EN-MEAN E DATA ERR-T 2311000400010 KEV KEV KEV MEV MB MB 2311000400011 12. 30. 20. 7.39 1.4 0.3 2311000400012 12. 30. 20. 4.77 0.6 0.2 2311000400013 30. 50. 41. 7.41 8.6 0.5 2311000400014 30. 50. 41. 4.79 0.5 0.1 2311000400015 50. 103. 74. 7.44 0.2 0.1 2311000400016 50. 103. 74. 4.82 0.4 0.1 2311000400017 ENDDATA 8 0 2311000400018 ENDSUBENT 17 0 2311000499999 ENDENTRY 4 0 2311099999999