ENTRY M0362 20120927 M064M036200000001 SUBENT M0362001 20120927 M064M036200100001 BIB 15 47 M036200100002 TITLE A study of the photoneutron reactions in B-10 AND M036200100003 B-11. M036200100004 AUTHOR (U.Kneissl,K.H.Leister,H.O.Neidel,A.Weller) M036200100005 INSTITUTE (2GERJLU) M036200100006 REFERENCE (J,NP/A,264,30,1976) M036200100007 #doi:10.1016/0375-9474(76)90142-1 M036200100008 FACILITY (LINAC,2GERJLU) M036200100009 INC-SOURCE (QMPH) Positron annihilation in flight. M036200100010 DETECTOR (SCIN) Gd-loaded liquid scintillator. M036200100011 METHOD (EXTB) M036200100012 SAMPLE In the B-11 experiment a sample of natural boron M036200100013 (80.39% B-11,19.61% B-10) of 11.04 g/sm**2 thickness M036200100014 was used. For B-10 measurements the enriched target M036200100015 (90.4 % B-10, 9.6% B-11) had thickness 5.69 g/sm**2. M036200100016 ANALYSIS A high efficiency neutron detector enables one to M036200100017 measure the photoneutron multiplicities directly. It M036200100018 then follows that the (g,xn) cross sections can be M036200100019 obtained separately by means of statistical M036200100020 considerations. The moments method which was further M036200100021 developed by Krueger was used. in order to measure M036200100022 absolute cross sections the photon flux, the photon M036200100023 energy and the efficiency of the neutron detector M036200100024 have been calibrated. M036200100025 ERR-ANALYS The statistical errors only. The absolute calibration M036200100026 error of the photon flux causes a systematic error M036200100027 of the measured cross sections of about 10%. M036200100028 REL-REF (N,,F.R.Krueger,J,NIM,125,285,1975) The moments M036200100029 method for statistical data consideration. M036200100030 CORRECTION The cross sections obtained were corrected for isotope M036200100031 impurities and photoneutron absorption in the sample M036200100032 (~ 5%). M036200100033 COMMENT Absolute (g,xn) cross sections for B-10 and B-11 were M036200100034 measured up to 35 MeV using quasimonoenergetic M036200100035 photon beam from positron annihilation in flight. M036200100036 The experimental cross sections were compared with M036200100037 many-particle shell-model calculations and data from M036200100038 previous bremsstrahlung experiments. The B-11 M036200100039 photoneutron cross section is discussed with respect M036200100040 to the possible isospin splitting. A systematic M036200100041 review of the photoneutron cross section of the M036200100042 p-shell nuclei integrated up to about 30 MeV seems M036200100043 to show a strong influence of the alpha-cluster M036200100044 structure of the target nuclei. M036200100045 HISTORY (19930421C) M036200100046 (20120927A) Corrected by V.Varlamov: dates, doi, M036200100047 lowercase. M036200100048 Entry deleted because of duplication with L0044. M036200100049 ENDBIB 47 0 M036200100050 COMMON 2 3 M036200100051 ERR-1 EN-RSL M036200100052 PER-CENT PER-CENT M036200100053 10. 1.25 M036200100054 ENDCOMMON 3 0 M036200100055 ENDSUBENT 54 0 M036200199999 NOSUBENT M0362002 20120927 M064M036200200001 NOSUBENT M0362003 20120927 M064M036200300001 NOSUBENT M0362004 20120927 M064M036200400001 NOSUBENT M0362005 20120927 M064M036200500001 NOSUBENT M0362006 20120927 M064M036200600001 NOSUBENT M0362007 20120927 M064M036200700001 NOSUBENT M0362008 20120927 M064M036200800001 NOSUBENT M0362009 20120927 M064M036200900001 ENDENTRY 9 0 M036299999999