ENTRY 20111 20101102 22252011100000001 SUBENT 20111001 20101102 22252011100100001 BIB 9 23 2011100100002 INSTITUTE (2AUSIRK) Work performed at Inst. fuer Radiumforshung 2011100100003 und Kernphysik, Vienna. 2011100100004 (2GERMUN) First author's address. 2011100100005 REFERENCE (J,ZP,237,155,197004) Main reference, data given 2011100100006 (J,OSA,107,(6),94,197004) 2011100100007 AUTHOR (H.Vonach, M.Hille, G.Stengl, W.Breunlich, E.Werner) 2011100100008 TITLE -Precision measurement of Al-27(n,alpha) cross-section 2011100100009 for 14.43 MeV neutrons.- (in German). 2011100100010 FACILITY (CCW,2AUSIRK) The Cockcroft-Walton accelerator at the 2011100100011 Institute fuer Radiumforschung und Kernphysik, Vienna.2011100100012 INC-SOURCE (D-T) T(d,n)-reaction, tritium-titanium target. 2011100100013 INC-SPECT .Neutron energy of 14.43 +- 0.015 MeV(error), 2011100100014 energy resolution of approximately 0.2 MeV. 2011100100015 METHOD (ACTIV) The induced Na-24 activity was measured. 2011100100016 (ASSOP) The neutron flux determined accurately by 2011100100017 associated particle method. 2011100100018 (COINC) 2011100100019 HISTORY (19701222C) 2011100100020 (19710908E) 2011100100021 (20071217A) Date is corrected 2011100100022 (20071217U) Last corrections have been done. 2011100100023 (20101002A) SD: Cosmetic corrections. + 2011100100024 Date of ref. on ZP was corrected. 2011100100025 ENDBIB 23 0 2011100100026 COMMON 1 3 2011100100027 EN-RSL 2011100100028 MEV 2011100100029 0.2 2011100100030 ENDCOMMON 3 0 2011100100031 ENDSUBENT 30 0 2011100199999 SUBENT 20111002 20071217 21902011100200001 BIB 9 67 2011100200002 REACTION (13-AL-27(N,A)11-NA-24,,SIG) 2011100200003 SAMPLE Aluminium plate, thickness 15 mm. 2011100200004 DETECTOR (SCIN ) Well-type crystal scintillator, 2011100200005 4pi*beta-gamma coincidence method used for 2011100200006 calibration of Na-24 standard source. The counter 2011100200007 efficiency for beta is about 99.5 per cent. 2011100200008 (SIBAR) Silicon surface barrier detector for alpha 2011100200009 counting (associated particle method) during 2011100200010 irradiation. 2011100200011 MONITOR 11-Na-24 standard source. 2011100200012 PART-DET (DG) Decay gammas 2011100200013 STATUS P.175 of Zs.Physik 237 (1970). 2011100200014 CORRECTION .Dead time correction for the alpha-counter. 2011100200015 .Alphas scattered in the collimators. 2011100200016 .Protons from the d(d,P)t reaction. 2011100200017 .Pile-up. 2011100200018 .Alphas and protons from background. 2011100200019 .Alphas from Cf-252 contamination in the detector. 2011100200020 .Dead time correction in the gamma measurement. 2011100200021 .Angle corrections for the motion of centre of mass 2011100200022 for neutrons and for alphas. 2011100200023 .Extension of sample and focus. 2011100200024 .Eccentricity of focus with respect to the target. 2011100200025 .Absorption and scattering of neutrons before 2011100200026 giving an (N,alpha) reaction. 2011100200027 ERR-ANALYS .By minimizing all sources of systematic errors, an 2011100200028 overall accuracy of 0.7 per-cent on a 99.5 (3*sigma) 2011100200029 confidence level was obtained. 2011100200030 .The errors in the measurement of the Al-27(N,alpha) 2011100200031 cross section are listed below, for statistical errors2011100200032 3*sigma is given, otherwise the estimated maximal 2011100200033 error. 2011100200034 ------------------------------------------------------2011100200035 Error source error(per-cent)2011100200036 ------------------------------------------------------2011100200037 (ERR-1) .Statistical error in the measurement 2011100200038 of the aluminium sample, 0.12 2011100200039 (ERR-2) .Statistical error in alpha counting, 0.06 2011100200040 (ERR-3) .Statistical error in calibration of the 2011100200041 well type crystal, 0.42 2011100200042 (ERR-4) .Systematical error in the 4pi*beta-gamma 2011100200043 calibration of the well type crystal, 0.15 2011100200044 (ERR-5) .Estimate of the contribution of 2011100200045 background, pile-up and other disturbing 2011100200046 processes to the alpha spectra. 0.10 2011100200047 (ERR-6) .Error in the measurement of the solid 2011100200048 angle in which alpha particles were 2011100200049 detected. 0.06 2011100200050 (ERR-7) .Error in the measurement of the distance 2011100200051 target-sample. 0.25 2011100200052 (ERR-8) .Error in the decay constant of Na-24, 0.10 2011100200053 (ERR-9) .Error in the correction for the 2011100200054 extension of the focal spot, 0.04 2011100200055 (ERR-10) .Error in the correction for neutron- 2011100200056 absorption, 0.20 2011100200057 (ERR-11) .Error in the correction for the neutron- 2011100200058 scattering, 0.20 2011100200059 (ERR-12) .Error in the correction factor for 2011100200060 the finite irradiation time and the 2011100200061 fluctuation of the neutron flux, 0.20 2011100200062 (ERR-13) .Error in the ratio of correction factor 2011100200063 for the anisotropy of neutron- and 2011100200064 alpha-emission in lab-system due to the 2011100200065 uncertainty of the tritium spread in the 2011100200066 target, 0.12 2011100200067 ------------------------------------------------------2011100200068 HISTORY (20071217A) Error structure is given.DATA-ERR -->ERR-T 2011100200069 ENDBIB 67 0 2011100200070 COMMON 13 9 2011100200071 ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 2011100200072 ERR-7 ERR-8 ERR-9 ERR-10 ERR-11 ERR-12 2011100200073 ERR-13 2011100200074 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2011100200075 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2011100200076 PER-CENT 2011100200077 0.12 0.06 0.42 0.15 0.10 0.06 2011100200078 0.25 0.10 0.04 0.20 0.20 0.20 2011100200079 0.12 2011100200080 ENDCOMMON 9 0 2011100200081 DATA 4 1 2011100200082 EN EN-ERR DATA ERR-T 2011100200083 MEV MEV B B 2011100200084 1.443E+01 1.50E-02 1.170E-01 8.0E-04 2011100200085 ENDDATA 3 0 2011100200086 ENDSUBENT 85 0 2011100299999 SUBENT 20111003 20071217 21902011100300001 BIB 7 13 2011100300002 REACTION (13-AL-27(N,A)11-NA-24,,SIG,,,DERIV) 2011100300003 ASSUMED (ASSUM,13-AL-27(N,A)11-NA-24,,SIG) 2011100300004 117.0 +- 0.8 mb at 14.43 MeV was used. 2011100300005 (See subentry 2). 2011100300006 PART-DET (DG) Decay gammas 2011100300007 COMMENT .The cross sections were calculated from the ratios 2011100300008 by Vonach et Al., Washington conf.(1968) vol.2,P.885. 2011100300009 And EANDC(E)-89,P.37,(1968). 2011100300010 STATUS (TABLE) Table 2 of Zs.Physik 237,155 (1970) 2011100300011 (DEP,20111002) 2011100300012 HISTORY (20071217U) Last corrections have been done. 2011100300013 ERR-ANALYS (DATA-ERR) Error (statistical plus systematic) 2011100300014 given in per-cent. 2011100300015 ENDBIB 13 0 2011100300016 COMMON 2 3 2011100300017 ASSUM ASSUM-ERR 2011100300018 MB MB 2011100300019 117.0 0.8 2011100300020 ENDCOMMON 3 0 2011100300021 DATA 3 13 2011100300022 EN DATA DATA-ERR 2011100300023 MEV B PER-CENT 2011100300024 1.36E+01 1.249E-01 1.2 2011100300025 1.37E+01 1.243E-01 1.2 2011100300026 1.38E+01 1.226E-01 1.2 2011100300027 1.39E+01 1.210E-01 1.2 2011100300028 1.40E+01 1.204E-01 1.2 2011100300029 1.41E+01 1.204E-01 1.2 2011100300030 1.42E+01 1.204E-01 1.2 2011100300031 1.43E+01 1.193E-01 1.2 2011100300032 1.44E+01 1.1763E-01 1.2 2011100300033 1.45E+01 1.154E-01 1.2 2011100300034 1.46E+01 1.142E-01 1.2 2011100300035 1.47E+01 1.120E-01 1.2 2011100300036 1.48E+01 1.103E-01 1.2 2011100300037 ENDDATA 15 0 2011100300038 ENDSUBENT 37 0 2011100399999 ENDENTRY 3 0 2011199999999