ENTRY 23068 20130203 22342306800000001 SUBENT 23068001 20130203 22342306800100001 BIB 12 69 2306800100002 TITLE Measurement of the branching ratio of the 2306800100003 Bi-209(n,gamma)Bi-210g/Bi-210m reactions at GELINA 2306800100004 REFERENCE (C,2007NICE,1,563,200704) 2306800100005 #doi:10.1051/ndata:07431 2306800100006 AUTHOR (A.Borella, T.Belgya, E.Berthoumieux, N.Colonna, 2306800100007 C.Domingo-Pardo, J.C.Drohe, F.Gunsing, S.Marrone, 2306800100008 T.Martinez, C.Massimi, P.M.Mastinu, P.M.Milazzo, 2306800100009 P.Schillebeeckx, G.Tagliente, J.Tain, R.Terlizzi, 2306800100010 R.Wynants) 2306800100011 INSTITUTE (2ZZZGEL) A.Borella,J.C.Drohe,P.Schillebeeckx,R.Wynants2306800100012 (2FR SAC) A.Borella,E.Berthoumieux. 2306800100013 (3HUNII ) T.Belgya,F.Gunsing. 2306800100014 (2ITYBAU) N.Colonna, S.Marrone, G.Tagliente,R.Terlizzi.2306800100015 (2SPNVAL) C.Domingo-Pardo,J.Tain. 2306800100016 (2SPNPCM) Centro de Investigaciones Energeticas 2306800100017 Medioambientales y Technologicas,Madrid, Spain; 2306800100018 - T.Martinez. 2306800100019 (2ITYBOL) C.Massimi. 2306800100020 (2ITYPAD) P.M.Mastinu. 2306800100021 (2ITYTRI) P.M.Milazzo. 2306800100022 REL-REF (I,,D.Tronc+,J,NIM/A,228,217,1985) 2306800100023 Detailed description of GELINA. 2306800100024 (M,,J.Briesmeister,R,LA-13709-M,2000). 2306800100025 MCNP - General Monte Carlo N-Particle Transport Code, 2306800100026 Version 4C2. 2306800100027 (N,,B.Fazekas+,J,JRC,215,111,1997). 2306800100028 Spectrum analysis program Hypermet-PC. 2306800100029 SAMPLE Disc of 62.214 g of metallic bismuth with a purity > 2306800100030 99.99%, diameter 81.0 mm, thickness 1.26 mm, 2306800100031 corresponding to 4.38E-3 at/b; positioned 2306800100032 perpendicularly to neutron beam. 2306800100033 FACILITY (LINAC,2ZZZGEL) Accelerator operated at 800 Hz , 2306800100034 60 microA average electron current. Electron pulses of 2306800100035 1 ns width with 100 MeV average electron energy. 2306800100036 800 hours of nominal accelerator operation. 2306800100037 INC-SOURCE (TAGD) Electron pulses 1 ns width with 100 MeV average 2306800100038 electron energy. Moderated neutron beam was collimated 2306800100039 to about 80mm in diameter at sample position. 2306800100040 4.16E-3 at/b thick B-10 anti-overlap filter and 2306800100041 permanent 30 mm thick Pb filter were used to reduce 2306800100042 effect of overlap neutrons and gamma-flash. 2306800100043 INC-SPECT High neutron flux . Resolution sufficient to resolve 2306800100044 resonances up to 20 keV. 2306800100045 METHOD (TOF) 12 m flight path. Angle between the flight path 2306800100046 and the direction of electron beam was 72 degrees. 2306800100047 To optimize the experimental conditions, particular 2306800100048 care was given to the reduction of background by using 2306800100049 an appropriate lead and boric acid shielding around 2306800100050 the measurement area. 2306800100051 (GSPEC) Experimental gamma-ray spectra up to deposited 2306800100052 energy (Ed) of 1.5 MeV were obtained for 6 energy 2306800100053 regions around Bi-209 neutron resonances at 0.80, 2.32,2306800100054 3.35, 4.46, 5.11, 6.53 keV. 2306800100055 DETECTOR (HPGE) Three high-purity germanium detectors 2306800100056 Large volume coaxial detector - to study gamma-ray 2306800100057 spectra up to an energy of 8 MeV; placed at 125 degrees2306800100058 with respect to the neutron beam. 2306800100059 Two planar detectors -to investigate gamma-ray spectrum2306800100060 in the low energy part; placed at 55 and 125 degrees 2306800100061 with respect to the neutron beam. 2306800100062 Detectors were shielded with Li-6NH(2) and Li-6(2)CO(3)2306800100063 caps together with Li-6F sheets. 2306800100064 Details about the impact of so-called neutron 2306800100065 sensitivity - in A.Borella+, Proc. American Nuc. Soc. 2306800100066 Topical Meeting on Reactor Physics, Vancouver, Canada, 2306800100067 B 042, (2006). 2306800100068 HISTORY (20090705C) M.M. 2306800100069 (20130203U) SD: Illegal blank from author's name in 2306800100070 REL-REF was deleted. 2306800100071 ENDBIB 69 0 2306800100072 NOCOMMON 0 0 2306800100073 ENDSUBENT 72 0 2306800199999 SUBENT 23068002 20090705 22142306800200001 BIB 6 37 2306800200002 REACTION (83-BI-209(N,G)83-BI-210-G/M,,SIG/RAT) 2306800200003 DECAY-DATA (32-GE-75,,DG,139.96) 2306800200004 139.96 keV gamma-ray from Ge-75, 511.06keV annihilation2306800200005 gamma-ray and 870.56 keV gamma-ray from O-17 were used 2306800200006 for an off-line adjustment of the gain using the most 2306800200007 recent version of AGL code. 2306800200008 ANALYSIS (AREA) The data, measured with the planar detector 2306800200009 positioned at 125 degrees with respect to the neutron 2306800200010 beam, were analyzed, monitored weekly by measuring a 2306800200011 Eu-152 calibration source. 2306800200012 Effective gamma-ray detection efficiency was deduced 2306800200013 with Monte Carlo simulation, using the MCNP code. MCNP 2306800200014 model was validated with measurements using a 2306800200015 well-characterized Eu-152 source. The model efficiency 2306800200016 reproduced the measured efficiency within 5%. 2306800200017 To deduce the full energy net peak areas, gamma-ray 2306800200018 spectra were analyzed with spectrum analysis program 2306800200019 Hypermet-PC [10]. 2306800200020 Net peak areas for the observed gamma-rays ranging from2306800200021 0.1 MeV to 1.5 MeV were obtained. 2306800200022 The branching ratio was obtained by calculating the 2306800200023 ratio between the sum of the resulting relative partial2306800200024 cross sections of the transition feeding the ground 2306800200025 state and the isomeric state. 2306800200026 CORRECTION Net peak areas were corrected for the effective 2306800200027 gamma-ray detection efficiency and for the internal 2306800200028 conversion effect. 2306800200029 ERR-ANALYS (ERR-T) Total uncertainty results from : 2306800200030 (ERR-1) 5% uncertainty adopted on the gamma-ray 2306800200031 efficiency, 2306800200032 and the uncertainty of the full energy net peak area. 2306800200033 STATUS (PRELM) Preliminary branching ratio as a function of 2306800200034 neutron energy for 6 energy regions (0.80, 2.32, 3.35, 2306800200035 4.46, 5.11, 6.53 keV) are given in Fig.5 of C,2007NICE.2306800200036 Request for the data was sent to A.Borella 07.07.2009.2306800200037 Answer 08.07.2009: "NOT to extract any data from the 2306800200038 figures in the article " . 2306800200039 ENDBIB 37 0 2306800200040 COMMON 1 3 2306800200041 ERR-1 2306800200042 PER-CENT 2306800200043 5. 2306800200044 ENDCOMMON 3 0 2306800200045 NODATA 0 0 2306800200046 ENDSUBENT 45 0 2306800299999 ENDENTRY 2 0 2306899999999