ENTRY 23132 20130110 22342313200000001 SUBENT 23132001 20130110 22342313200100001 BIB 17 197 2313200100002 TITLE Resonance parameters for 197Au + n below 200 eV 2313200100003 AUTHOR (C.Massimi, A.Borella, S.Kopecky, C.Lamboudis, 2313200100004 M.C.Moxon, P.Schillebeeckx, G.Vannini) 2313200100005 INSTITUTE (2ITYUBO,2ZZZGEL) 2313200100006 (2UK UK ) Hyde Copse, Marchan,3 United Kingdom 2313200100007 REFERENCE (J,NC/B,125,517,2010) 2313200100008 #doi:10.1393/ncb/i2010-10847-9 2313200100009 (J,KPS,59,1689,2011) Same Res.Par. at 4.9 eV given 2313200100010 REL-REF (I,,M.Flaska+,J,NIM/A,531,392,2004) 2313200100011 Description of the accelerator and its neutron 2313200100012 producing target 2313200100013 (I,,C.Coceva+,R,IRMM-06,1996) 2313200100014 IRMM internal report GE/R/ND/06/96 2313200100015 1(I,,S.Kopecky+,J,NP/A,773,173,2006) 2313200100016 Detailed description of the exp. setup for 2313200100017 transmission measurements. 2313200100018 2(I,,A.Borella+,J,NIM/A,577,636,2007) 2313200100019 Description of the method and of the calculation of 2313200100020 weighting function 2313200100021 SAMPLE Temperature at the sample position was continuously 2313200100022 monitored. The average temperature was used in the 2313200100023 resonance shape analysis to account for Doppler effect.2313200100024 1 Samples of thickness 2313200100025 - 10.0 microm (5.861E-5 at/b), 2313200100026 20.0 microm (1.163E-4 at/b), 2313200100027 50.0 microm(2.906E-4 at/b) 2313200100028 using 50 Hz frequency and natural Cd filter to prevent 2313200100029 overlapping between neutron bunches; 2313200100030 - 3.0 mm (1.757E-2 at/b) using 800 Hz frequency and 2313200100031 B-10 filter to prevent overlapping between neutron 2313200100032 bunches. 2313200100033 2 At 12.5 m flight path (and 50 Hz frequency) - samples 2313200100034 of thickness 0.5 mm (3.097E-3 at/b) using Co,Bi,Na 2313200100035 filters for background, with and without natural Cd 2313200100036 filter to prevent overlapping between neutron bunches. 2313200100037 At 30 m flight path: 2313200100038 - 50 Hz frequency and natural Cd filter to prevent 2313200100039 overlapping, samples of thickness 2313200100040 1.0mm(6.007E-3 at/b) using Na filter for background, 2313200100041 0.5mm(3.097E-3 at/b) using W,Co,Na filters for 2313200100042 background, 2313200100043 0.5 mm (3.097E-3 at/b), 0.1 mm (5.945E-4 at/b), 2313200100044 50.0 microm (2.906E-4at/b), 10.0 microm (5.861E-5at/b),2313200100045 5.0 microm (2.772 at/b) using Na filter for background;2313200100046 - 800 Hz frequency and B-10 filter to prevent 2313200100047 overlapping, samples of thickness 2313200100048 1.0mm (6.07E-3at/b), 0.5 mm(3.097E-3 at/b), 2313200100049 0.1 mm (5.940E-4 at/b); 2313200100050 0.1 mm (5.940E-4 at/b) using Na filter for background; 2313200100051 0.1 mm (5.940E-4 at/b) using S filter for background. 2313200100052 3 0.1 mm thick Au foil was placed at a 7 m distance from2313200100053 the neutron producing target. The areal density of the 2313200100054 Au filter (5.886E-4 at/b) was similar compared to the 2313200100055 one of the capture sample (5.945E-4 at/b). 2313200100056 FACILITY (LINAC,2ZZZGEL) GELINA at IRMM . 2313200100057 INC-SOURCE (PHOTO) Pulsed white neutron source. Electron pulses 2313200100058 (max.repetition rate 800 Hz, peak current up to 12 A 2313200100059 in 10 ns time interval) are accelerated up to 150 MeV. 2313200100060 Post-acceleration magnet compresses electron bunches 2313200100061 to width < 1 ns (peak current 120 A). 2313200100062 Electrons generate bremsstrahlung in rotating uranium 2313200100063 target - neutrons were mainly produced by gamma,n and 2313200100064 gamma,f reactions. 2313200100065 Water-filled Be containers as moderators. 2313200100066 INC-SPECT Direct - fast neutron spectrum with very good time 2313200100067 resolution. 2313200100068 Moderated - slow neutron spectrum at reduced energy 2313200100069 resolution. 2313200100070 METHOD (TOF) 0.5 ns resolution. 2313200100071 1(TRN) Neutron detectors were placed at 49.345+-0.006 m 2313200100072 distance from neutron producing target. Samples were 2313200100073 placed almost halfway between detector and neutron 2313200100074 producing target. Angle between the flight path and 2313200100075 the normal to the moderator was -9 deg. 2313200100076 (FNB) Sample changer was also used to place black 2313200100077 resonance filters (i.e. S, Na, Co, W, and Ag) for 2313200100078 background determination applying the black resonance 2313200100079 technique. All measurements have been performed 2313200100080 with at least one fixed black resonance filter in beam.2313200100081 The background level at 4.9 eV for a sample out 2313200100082 measurement was < 1% and about 10% for measurements 2313200100083 with a 10 microm thick Au sample in the beam. 2313200100084 30mm diameter neutron beam at the sample position. 2313200100085 (PHD) Pulse-height window selects the alpha-peak of 2313200100086 Li-6(n,alpha) reaction to distinguish a neutron event 2313200100087 from background events. 2313200100088 2 Capture measurements at nominal flight path distances 2313200100089 of 12.5 m, 30 m , 60 m (angle between the flight path 2313200100090 and the normal to the moderator is 18, 0 and 9 degrees,2313200100091 respectively).Moderated neutron beam was collimated to 2313200100092 75 mm diameter at the sample position. 2313200100093 At about 1m from the sample a shielding of boron-oxide 2313200100094 and paraffin together with a 10 cm thick lead wall, 2313200100095 was placed to reduce the background. 2313200100096 Pulse height weighting technique was used to create 2313200100097 detector response proportional to the energy of the 2313200100098 registered gamma. 2313200100099 3 Self-indication measurements at 30 m flight path using2313200100100 the same setup as for capture measurements. 2313200100101 Au filter (squared metal disc 21.7x22.0 cm, areal 2313200100102 density of 5.886*10-4 atoms/barn,nominal thickness 2313200100103 0.11 mm) was placed at the beginning of the neutron 2313200100104 beam pipe, far from the measurement station. 2313200100105 PART-DET 1(N) 2313200100106 2(G) 2313200100107 DETECTOR Response function was investigated using MONTE Carlo 2313200100108 calculation - REL-REFs of M.Flaska+, C.Coceva+. 2313200100109 Fe-56(n,gamma) capture measurements at 60 m Flight Path2313200100110 (A.Borella+, Int.Workshop on P&T and ADS Development, 2313200100111 SCK*CEN, Mol, Belgium, 6-8 October,2003) - to validate 2313200100112 resolution function. 2313200100113 1(BF3) BF3 proportional counters - to monitor 2313200100114 output and stability of the accelerator and to 2313200100115 normalize the sample-in and sample-out measurements to 2313200100116 the same total neutron intensity. 2313200100117 (GLASD) Li-glass scintillator (NE 912), enriched to 95%2313200100118 in Li-6 of 1/4 inch (6.35mm) thickness, 4 inch(101.6mm)2313200100119 diameter, viewed by a photo-multiplier. 2313200100120 Background as a function of TOF was derived by black 2313200100121 resonance technique. 2313200100122 2(SCIN) C6D6 liquid scintillator array. Each detector 2313200100123 was positioned at an angle of 125 degrees with respect 2313200100124 to the direction of the neutron beam. 2313200100125 Each scintillator was coupled to a quartz windowed 2313200100126 (boron free) photomultiplier. 2313200100127 Threshold for the deposited energy of the detection 2313200100128 system at 12.5 m, 30 m, and 60 m was set to 200 keV, 2313200100129 150 keV and 150 keV, respectively. 2313200100130 Linearity and resolution of the C6D6 detectors were 2313200100131 monitored on a weekly basis by measurements of the 2313200100132 2.6 MeV gamma-ray from the Th-232 decay chain. 2313200100133 (IOCH) B-10 Frisch gridded ionization chambers placed 2313200100134 at 80 cm before the capture sample -to monitor shape of2313200100135 neutron spectrum. Double chamber was used with cathode 2313200100136 loaded with two back-to-back layers of about 2313200100137 40 microg/cm2 B-10, effective diameter of 84 mm, 2313200100138 evaporated on a 30 microm thick aluminum backing. 2313200100139 Chambers were operated with continuous flow of mixture 2313200100140 of argon (90%) + methane (10%) at atmospheric pressure.2313200100141 ANALYSIS To derive the transmission and the capture yield from 2313200100142 the raw TOF spectra the data reduction package AGS 2313200100143 (Analysis of Geel Spectra) developed at the IRMM was 2313200100144 used - C.Bastian, AGS,"set of UNIX commands for neutron2313200100145 data reduction", Proc.Int.Conf. on Neutron Research and2313200100146 Industry, Crete, Greece, 1996, Ed. G.Vourvopoulos, 2313200100147 SPIE - International Society for Optical Engineering, 2313200100148 Vol. 2867, 611, 1997 : 2313200100149 AGS code controls the most important spectra 2313200100150 manipulations: dead time correction, background fitting2313200100151 and subtraction and normalization; performs full 2313200100152 propagation of uncertainties, starting from the 2313200100153 uncorrelated uncertainties due to counting statistic; 2313200100154 includes complete covariance matrix accounting for both2313200100155 uncorrelated and correlated uncertainty components. 2313200100156 Resonance shape analysis code REFIT is used to 2313200100157 parameterize the data in terms of resonance parameters.2313200100158 The code is based on the Reich-Moore approximation of 2313200100159 the R-matrix formalism and accounts for self-shielding,2313200100160 multiple scattering and Doppler effects, the resolution2313200100161 of the spectrometer, neutron sensitivity of the capture2313200100162 detection system and attenuation of gamma-rays in 2313200100163 sample. 2313200100164 Normalization of capture yields and self-indication 2313200100165 data was done by means of the saturated resonance 2313200100166 technique applied to the 4.9-eV Au resonance. 2313200100167 For capture measurements with thin samples the 2313200100168 normalization was derived from nearby resonances, 2313200100169 for which the resonance parameters were determined 2313200100170 from the thick sample data. 2313200100171 MONITOR (5-B-10(N,A)3-LI-7,,SIG) C-s were used to drive 2313200100172 (5-B-10(N,TOT),,SIG) capture yields. 2313200100173 CORRECTION For dead-time - maximum correction for neutron energies2313200100174 below 500 eV was 2%. 2313200100175 In capture measurement for the flux measurements the 2313200100176 dead time was 3500 ns, with a maximum dead-time 2313200100177 correction less than 1% at the two stations. The dead 2313200100178 time for the capture measurement systems was 2800 ns. 2313200100179 For the measurements at the 12.5m and 30m station 2313200100180 maximum dead-time corrections were < 20% and 5%, 2313200100181 respectively. 2313200100182 For the attenuation in the exit window of ionization 2313200100183 chamber and the attenuation due to the 80 cm air 2313200100184 between ionization chamber and target. 2313200100185 For background. In transmission measurement 2313200100186 - for sample-out < 1%, 2313200100187 - for sample-in up to 10% at 4.9 eV . 2313200100188 In capture measurement time-dependent background was 2313200100189 monitored during runs having only the sample holder in 2313200100190 the neutron beam; additional 0.5 mm thick Pb-208 sample2313200100191 measurement was done to estimate the background due to 2313200100192 scattered neutrons. 2313200100193 ERR-ANALYS1(ERR-1,,0.5) Uncertainty of normalization factor in 2313200100194 transmission measurement 2313200100195 HISTORY (20110719C) M.M. 2313200100196 Request of data of all resonances was sent to 2313200100197 Cristian Massimi - massimi@bo.infn.it 2011-07-28. 2313200100198 (20130110U) On. MONIT=4.9 eV deleted. 2313200100199 ENDBIB 197 0 2313200100200 NOCOMMON 0 0 2313200100201 ENDSUBENT 200 0 2313200199999 SUBENT 23132002 20110719 22282313200200001 BIB 6 18 2313200200002 REACTION 1(79-AU-197(N,0),,EN) Resonance energy. 2313200200003 2(79-AU-197(N,EL),,WID) Neutron width. 2313200200004 3(79-AU-197(N,G),,WID) Gamma width. 2313200200005 ANALYSIS (MLA) REFIT code, based on the Reich-Moore 2313200200006 approximation of the multi-level R-matrix formalism, 2313200200007 was used to calculate the resonance parameters 2313200200008 performing a simultaneous fit of several data sets. 2313200200009 Adjusted parameters: energy, neutron and radiation 2313200200010 width.Resonance energy was determined from transmission2313200200011 data at 49.34 m, where the time-energy calibration was 2313200200012 adjusted to the U-238 resonance at 6.673 +- 0.001 eV. 2313200200013 REL-REF (A,,R.C.Block+,C,94GATLIN,81,1994) Agree within 1%. 2313200200014 ERR-ANALYS (ERR-S) Statistical uncertainty. 2313200200015 STATUS (TABLE) Text, page 526 of J,NC/B,125,517,2010. 2313200200016 Text, last page of J,KPS,58,(1061),2011. 2313200200017 COMMENT This work was supported by the European Commission 2313200200018 within the Sixth Framework Program through I3-EFNUDAT 2313200200019 ,EURATOM contract No. 036434. 2313200200020 ENDBIB 18 0 2313200200021 NOCOMMON 0 0 2313200200022 DATA 8 1 2313200200023 DATA 1ERR-S 1DATA 2ERR-S 2DATA 3ERR-S 32313200200024 PARITY SPIN J 2313200200025 EV EV MILLI-EV MILLI-EV MILLI-EV MILLI-EV 2313200200026 NO-DIM NO-DIM 2313200200027 4.8995 0.0002 14.96 0.02 121.4 0.3 2313200200028 +1. 2. 2313200200029 ENDDATA 6 0 2313200200030 ENDSUBENT 29 0 2313200299999 SUBENT 23132003 20110719 22282313200300001 BIB 3 10 2313200300002 REACTION (79-AU-197(N,G),,WID/STR) Capture kernel. 2313200300003 REL-REF (A,14086002,R.C.Block+,C,94GATLIN,1,81,1994) RPI 2313200300004 (A,23067001,Massimi+,J,PR/C,81,044616,2010) n TOF 2313200300005 Deviations on average by 2% and 1%,respectively. 2313200300006 Maximum deviation is less than 5% 2313200300007 STATUS (UNOBT) Request for the data was sent 28-07-2011 to 2313200300008 Cristian Massimi - massimi@bo.infn.it . 2313200300009 Data are on Fig.3 of J,KPS,58,(1061),2011 2313200300010 and on Fig.1 of J,NC/B,125,517,2010 2313200300011 as ratios to kernels measured at RPI and n TOF. 2313200300012 ENDBIB 10 0 2313200300013 NOCOMMON 0 0 2313200300014 NODATA 0 0 2313200300015 ENDSUBENT 14 0 2313200399999 SUBENT 23132004 20130110 22342313200400001 BIB 4 8 2313200400002 REACTION 1(79-AU-197(N,TOT),,TRN) Transmission 2313200400003 2(79-AU-197(N,G)79-AU-198,,RYL) Capture yield 2313200400004 3(79-AU-197(N,G)79-AU-198,,SIF) Self-indication 2313200400005 ADD-RES (COMP) Comparison with REFIT code calculations 2313200400006 STATUS (UNOBT) Fig.2 of Nuovo.Cim.B125(2010)517 2313200400007 Transmission, capture yield and self-indication 2313200400008 yields for 5, 10, 20, and 100 um thick samples 2313200400009 HISTORY (20130110A) On. REACTION: ,TRN,,RYL -> ,RYL 2313200400010 ENDBIB 8 0 2313200400011 NOCOMMON 0 0 2313200400012 NODATA 0 0 2313200400013 ENDSUBENT 12 0 2313200499999 ENDENTRY 4 0 2313299999999