ENTRY M0663 20120405 M063M066300000001 SUBENT M0663001 20120405 M063M066300100001 BIB 15 56 M066300100002 TITLE s-process branching at 185W revised. M066300100003 AUTHOR (P.Mohr,T.Shizuma,H.Ueda,S.Goko,A.Makinaga,K.Y.Hara, M066300100004 T.Hayakawa,Y.-W.Lui,H.Ohgaki,H.Utsunomiya) M066300100005 INSTITUTE (2GERTHD,2JPNJAE,2JPNKON,1USATAM,2JPNKTO,2JPNJPN) M066300100006 REFERENCE (J,PR/C,69,032801,2004) M066300100007 FACILITY (ESTRG,2JPNAIS) Electron storage ring TERAS at AIST M066300100008 (Tsukuba, Japan). M066300100009 INC-SOURCE (MPH,LCS) Tunable monochromatic photon source from M066300100010 laser Compton scattering - Laser Compton Scattering M066300100011 photons, LCS. M066300100012 DETECTOR (HE3SP) Improved neutron detector consisted of 16 M066300100013 individual 3He counters embedded in two rings in a M066300100014 polyethylene moderator. M066300100015 METHOD (RINGR) Direct measurement of photoneutrons using the M066300100016 ring-ratio method: ring-ratio (rr) between the count M066300100017 rates of the inner and outer detector rings depends M066300100018 on the neutron energy, and hence rr be used to M066300100019 estimate the neutron energy. That varied between 2.5 M066300100020 and 4.4 leading to average neutron energies of about M066300100021 1.2 MeV at highest photon energies and of about 0.3 M066300100022 MeV at lower photon energies. M066300100023 SAMPLE The target consisted of 1246 mg metallic tungsten M066300100024 powder highly enriched in 186W to 99.79 % The powder M066300100025 was pressed to a small self-supporting tablet with a M066300100026 diameter of 8 mm. M066300100027 ANALYSIS (UNFLD) For estimation of the reaction cross section M066300100028 from the experimental reaction yield the unfolding M066300100029 procedure using the replacement of integral equation M066300100030 by Taylor series (because the difference (low-energy M066300100031 tail) of realistic photon spectrum from ideal is M066300100032 relatively small) was used. M066300100033 ERR-ANALYS (ERR-S) Statistical errors. M066300100034 (ERR-SYS) Systematical uncertainties are dominated M066300100035 by the efficiency of the neutron detector (5 %) and M066300100036 the gamma-ray flux (3%). M066300100037 STATUS (TABLE) Data of Table 1 of Phys.Rev.,C72(2005)025808 M066300100038 were compiled at the Russia MSU SINP CDFE by M066300100039 V.V.Varlamov. M066300100040 (DEP,M0676002) M066300100041 REL-REF (R,,T.SHIZUMA+,J,PR/C,72,025808,2005) M066300100042 COMMENT The neutron capture cross section of the unstable M066300100043 s-process branching nucleus 185W has been derived M066300100044 from experimental data of inverse 186W(g,n)185W M066300100045 photodisintegration taken with monochromatic photon M066300100046 beams from laser Compton scattering. The result of M066300100047 SIG = 553 (60) mb at kT = 30 keV leads to a M066300100048 relatively high effective neutron density in the M066300100049 classical s-process of Nn = 4.7 x 10**8 sm**-3. A M066300100050 realistic model for the s-process in thermally M066300100051 pulsing asymptotic giant branch stars overestimates M066300100052 the abundance of 186Os significantly because of the M066300100053 relatively small neutron capture cross section of M066300100054 185W. M066300100055 HISTORY (20050118C) M066300100056 (20120405A) Corrected by V.Varlamov: data M066300100057 substituted. M066300100058 ENDBIB 56 0 M066300100059 NOCOMMON 0 0 M066300100060 ENDSUBENT 59 0 M066300199999 SUBENT M0663002 20120405 M063M066300200001 BIB 1 1 M066300200002 REACTION (74-W-186(G,N)74-W-185,,SIG) M066300200003 ENDBIB 1 0 M066300200004 NOCOMMON 0 0 M066300200005 DATA 4 15 M066300200006 EN DATA ERR-S ERR-SYS M066300200007 MEV MB MB MB M066300200008 7.26 7.4 1.35 .43 M066300200009 7.33 15.7 1.1 1.0 M066300200010 7.36 14.3 .5 .9 M066300200011 7.51 19.6 .6 1.1 M066300200012 7.72 23.7 .7 1.4 M066300200013 7.79 21.1 .8 1.3 M066300200014 7.88 25.0 .6 1.5 M066300200015 8.20 27.6 .9 1.6 M066300200016 8.63 35.7 .8 2.1 M066300200017 8.67 35.5 .9 2.1 M066300200018 8.91 38.8 .7 2.3 M066300200019 9.34 46.3 .8 2.7 M066300200020 9.96 67.1 1.3 3.9 M066300200021 10.35 88.7 1.2 5.2 M066300200022 10.87 122. 2. 7. M066300200023 ENDDATA 17 0 M066300200024 ENDSUBENT 23 0 M066300299999 ENDENTRY 2 0 M066399999999