ENTRY 30799 20010129 00003079900000001 SUBENT 30799001 20010129 00003079900100001 BIB 16 71 3079900100002 INSTITUTE (3POLITJ) 3079900100003 REFERENCE (J,ANE,15,(3),155,1988) 3079900100004 (J,ANE,26,83,1999) Corrected absolute cross sections 3079900100005 AUTHOR (J.JANCZYSZYN,G.DOMANSKA,W.POHORECKI,L.LOSKA,F.PACH) 3079900100006 TITLE Precise measurement of the integral cross section for 3079900100007 the reaction Mg-24(n,p)Na-24 between 13.5 and 18.0 MeV 3079900100008 FACILITY (VDG,3POLIPJ) 3 MV Van de Graaff accelerator in the 3079900100009 Institute of Nuclear Problems in Warsaw used for 3079900100010 producing neutron gives a 50 micro-Ampere deuteron 3079900100011 beam. 3079900100012 INC-SOURCE (D-T) T(d,n)He-4 reaction. 3079900100013 Applied T-target in the form if Titanium Tritide was 3079900100014 about 0.5 milli-gram/cm thick. The dia. of the beam 3079900100015 hot spot on the target was 6 mm. 3079900100016 INC-SPECT Monoenergetic neutrons with energies between 13 and 3079900100017 18 MeV. 3079900100018 SAMPLE 99.7 % Mg and 99.99 % Al pure metallic samples. 3079900100019 Sample weight of about 120 milli-gram for Mg and 3079900100020 170 milli-gram for Al was chosen. 3079900100021 METHOD (ACTIV) 3079900100022 Mg and Al samples were activated simultaneously in the 3079900100023 same position and were counted directly one after 3079900100024 another for equal counting times 3079900100025 DETECTOR (NAICR) 7.5*7.5-cm NaI(Tl) detector 3079900100026 MONITOR (13-AL-27(N,A)11-NA-24,,SIG) 3079900100027 Values were obtained by recalculation of nuclear data 3079900100028 standards for nuclear measurements, p. 59, IAEA 3079900100029 Technical Report Series no. 227, Vienna. by H.Vonach 3079900100030 (1983), and Physics Data. Compilation Series, 3079900100031 Fachinformationszentrum Energie, Physik, Mathematik, 3079900100032 Karlsruhe, 13 - 1 by S.Tagesen, H.Vonach and 3079900100033 B.Strohmaier (1979). Recalculations were made under 3079900100034 assumption that the activating neutron flux had a 3079900100035 truncated Gaussian distribution. It was assumed also 3079900100036 that the FWHM of the distribution is equal to double 3079900100037 the value of the energy resolution for the given 3079900100038 neutron energy. Values of cross section were then 3079900100039 calculated by numerical integration of the Sig(E) 3079900100040 function over the energy interval of one FWHM on both 3079900100041 sides of the given experimental neutron energy. The 3079900100042 values of Sig(E) were obtained by a polynomial 3079900100043 interpolation between the values of Tagesen et al. 3079900100044 (1979) and Vonach (1983). 3079900100045 MONIT-REF (,H.VONACH,R,STI/DOC/10-227,59,198310) 3079900100046 ERR-ANALYS -Statistical 3079900100047 -Systematic 3079900100048 Most of the systematic errors were eliminated in 3079900100049 the applied procedure. 3079900100050 Only two sources of errors (chemical purity and 3079900100051 isotopic composition) were not taken into consideration3079900100052 COMMENT Differences between given values of Mg-24(n,p)Na-24 3079900100053 reaction cross section and those of Exfor V0014002 3079900100054 are rather small and only for the highest neutron 3079900100055 energies, 17.09 and 17.86 MeV are remarkable. 3079900100056 Uncertainties of the obtained cross-section values 3079900100057 range from 2 to 4 mb, and are lower than the values of 3079900100058 exfor V0014002 for most neutron energies. The best 3079900100059 improvement is reached for 14.78 and 15.23 MeV neutron 3079900100060 energies, for which the ratio of cross-section 3079900100061 uncertainty for the investigated and reference reaction3079900100062 is the highest. 3079900100063 STATUS Corrected data of absolute cross section taken from 3079900100064 J.Ann.Nucl.Energy, Vol.26 (1999), Pag.88 Table 3 3079900100065 Ratios and monitor data taken from 3079900100066 J.Ann.Nucl.Energy, Vol.15(1988) Pag.155, Table 3. 3079900100067 HISTORY (19880622C) DG.- 3079900100068 (19881212A) TMK. Appended in BIB. section, reaction 3079900100069 ratio and data for ratio added. 3079900100070 (20010129A) VZ Absolute cross sections were corrected 3079900100071 for contributions of Mg-25(n,np+d) 3079900100072 and Mg-26(n,t+nd+2np) 3079900100073 ENDBIB 71 0 3079900100074 NOCOMMON 0 0 3079900100075 ENDSUBENT 74 0 3079900199999 SUBENT 30799002 20010129 00003079900200001 BIB 2 6 3079900200002 REACTION 1((12-MG-24(N,P)11-NA-24,,SIG)/ 3079900200003 (13-AL-27(N,A)11-NA-24,,SIG)) 3079900200004 2(12-MG-24(N,P)11-NA-24,,SIG) 3079900200005 DECAY-DATA (11-NA-24,14.960HR,DG,1368.,, 3079900200006 DG,2754.) 3079900200007 Uncertainty of half-life is 0.006 hr. 3079900200008 ENDBIB 6 0 3079900200009 NOCOMMON 0 0 3079900200010 DATA 8 13 3079900200011 EN EN-RSL DATA 1ERR-T 1MONIT MONIT-ERR 3079900200012 DATA 2ERR-T 2 3079900200013 MEV MEV NO-DIM NO-DIM MB MB 3079900200014 MB MB 3079900200015 13.59 0.27 1.607 0.014 125.2 0.6 3079900200016 199.7 2.0 3079900200017 14.17 0.33 1.628 0.015 120.6 0.6 3079900200018 193.9 2.0 3079900200019 14.78 0.28 1.567 0.013 112.6 0.7 3079900200020 173.2 2.0 3079900200021 15.23 0.20 1.567 0.017 108.0 1.5 3079900200022 165.2 3.0 3079900200023 15.40 0.24 1.595 0.018 105.7 1.8 3079900200024 164.2 3.4 3079900200025 15.54 0.22 1.600 0.015 103.5 1.9 3079900200026 161.1 3.5 3079900200027 15.93 0.25 1.558 0.014 95.8 1.8 3079900200028 144.1 3.2 3079900200029 16.23 0.18 1.623 0.015 89.3 1.8 3079900200030 139.3 3.2 3079900200031 16.29 0.28 1.630 0.015 88.1 1.7 3079900200032 137.9 3.1 3079900200033 16.59 0.15 1.646 0.014 81.8 1.7 3079900200034 128.3 3.1 3079900200035 16.77 0.34 1.642 0.019 78.9 1.8 3079900200036 122.9 3.3 3079900200037 17.09 0.12 1.618 0.020 73.6 1.9 3079900200038 112.1 3.4 3079900200039 17.86 0.08 1.791 0.020 62.9 2.1 3079900200040 112.7 4.0 3079900200041 ENDDATA 30 0 3079900200042 ENDSUBENT 41 0 3079900299999 ENDENTRY 2 0 3079999999999