ENTRY 22953 20230518 2295300000001 SUBENT 22953001 20230518 20231011 2295300100001 BIB 14 66 2295300100002 TITLE A detection system for (n,n') reaction studies of 2295300100003 astrophysical interest. 2295300100004 AUTHOR (M.Segawa,Y.Temma,Y.Nagai,T.Masaki,T.Shima,T.Ohta, 2295300100005 A.Nakayoshi,J.Nishiyama,M.Igashira) 2295300100006 REFERENCE (J,NIM/A,564,370,2006) Main Reference. 2295300100007 (J,JPJ,74,2981,2005) Method to prepare Li-7 targets. 2295300100008 REL-REF (M,,A.Tomyo+,J,AJ,623,L153,2005) Details of detector 2295300100009 efficiency correction 2295300100010 INSTITUTE (2JPNOSA) M.Segawa, Y.Temma, Y.Nagai, T.Masaki, 2295300100011 T.Shima, T.Ohta, A.Nakayoshi 2295300100012 (2JPNTIT) J.Nishiyama, M.Igashira 2295300100013 FACILITY (VDGT,2JPNTIT) The 3.2 MV Pelletron accelerator of the 2295300100014 Research Laboratory for Nuclear Reactors at the Tokyo 2295300100015 Institute of Technology. 2295300100016 INC-SOURCE (P-LI7) Li-7(p,n)Be-7 reaction. The proton energy was 2295300100017 adjusted so as to produce neutrons between 10 and 2295300100018 80 keV. Metallic layers of natural Li, evaporated onto2295300100019 copper disk, thickness 0.4 mm cooled by water. Average2295300100020 beam current of 5 microA at repetition rate 2 MHz. 2295300100021 INC-SPECT Low-energy neutrons 2295300100022 DETECTOR (GLASD) Four 6-Li glass detectors of 50 mm diameter and2295300100023 10 mm thickness. Energy resolution 20%, defined by 2295300100024 measured energy spectrum of scattered neutron by gold 2295300100025 sample. Time resolution 1.5 nsec (FWHM) obtained from 2295300100026 TOF spectrum using gamma-ray from LI-7(p,gamma)Be-8 2295300100027 reaction. Detectors were surrounded by neutron shield 2295300100028 composed of boron-doped polyethylene blocks with 2295300100029 tapered collimator. Detector was set at 90deg. to 2295300100030 proton beam direction. 2295300100031 Li-6-glass detector of 5mm diameter and 5mm thickness 2295300100032 for monitoring of incident neutron energy spectrum. 2295300100033 Placed at 0deg. to proton beam direction,30cm downward2295300100034 from neutron production target. 2295300100035 SAMPLE Os-186 metallic powder of 0.34g weight and 99.55% 2295300100036 enrichment in Os-186. Gold sample of 0.19 g weight. 2295300100037 Sample was placed 2cm downward from Li-7 neutron 2295300100038 production target. Os,Au,C samples were wrapped by 2295300100039 aramid sheet of 4 microm thickness. 2295300100040 METHOD (TOF) Neutron production target - sample distance =2cm.2295300100041 25/20 cm distance from sample to detectors. 2295300100042 TOF spectrums were measured 1)without sample, 2295300100043 2) with and without adding 0.4mm thick copper disk on 2295300100044 existing copper backing (0.4mm), 2295300100045 3) for water and air cooling for copper backing. 2295300100046 (SITA) Measurement was carried out cyclically by 2295300100047 changing four samples of Os-186, Au, C and blank 2295300100048 position. 2295300100049 ANALYSIS (REDUC) Constant background subtracted from TOF 2295300100050 spectrum for Os,C and blank samples were obtained. 2295300100051 TOF spectrum for blank sample was subtracted from 2295300100052 that for Os and C to obtain net TOF spectrum, which 2295300100053 was used to define neutron energy spectrum for 2295300100054 osmium and carbon. 2295300100055 CORRECTION Correction factors at EN 20.-40. keV Energy: 2295300100056 for multiple-scattering effects of incident neutrons 2295300100057 in Au sample - 1.00, 2295300100058 in Os-186 sample - 1.01, 2295300100059 in C sample - 1.01, 2295300100060 for shielding of incident neutrons 2295300100061 in Au sample - 0.98, 2295300100062 in Os-186 sample - 0.96, 2295300100063 in C sample - 0.95. 2295300100064 HISTORY (20070123C) M.M. 2295300100065 (20170825A) SD: Subent 002 deleted (Raw data, not 2295300100066 for EXFOR compilation) 2295300100067 (20230518A) SD: Correction in Subent 003. 2295300100068 ENDBIB 66 0 2295300100069 NOCOMMON 0 0 2295300100070 ENDSUBENT 69 0 2295300199999 NOSUBENT 22953002 20170825 22652295300200001 SUBENT 22953003 20230518 20231011 2295300300001 BIB 4 8 2295300300002 REACTION (79-AU-197(N,EL)79-AU-197,,SIG) 2295300300003 ERR-ANALYS (ERR-T) Presented uncertainty around 5.% 2295300300004 (ERR-S) Statistical error of yield. 2295300300005 (ERR-1) Uncertainty of elastic scattering cross 2295300300006 section for carbon. 2295300300007 STATUS (TABLE) Values presented on p.376 and on Fig.8 of 2295300300008 Nucl.Instr.Meth.,A564(2006)370 2295300300009 HISTORY (20230518A) SD: ERR-T deleted from COMMON section. 2295300300010 ENDBIB 8 0 2295300300011 COMMON 2 3 2295300300012 ERR-S ERR-1 2295300300013 PER-CENT PER-CENT 2295300300014 3. 4. 2295300300015 ENDCOMMON 3 0 2295300300016 DATA 3 3 2295300300017 EN DATA ERR-T 2295300300018 KEV B B 2295300300019 21.5 12.9 0.7 2295300300020 39.0 11.9 0.6 2295300300021 58.8 10.7 0.5 2295300300022 ENDDATA 5 0 2295300300023 ENDSUBENT 22 0 2295300399999 ENDENTRY 2 0 2295399999999