ENTRY M0782 20100212 M052M078200000001 SUBENT M0782001 20100212 M052M078200100001 BIB 14 37 M078200100002 TITLE Photofission of 235U and 237Np with bremsstrahlung M078200100003 photons below 20 MeV: measurements of delayed neutron M078200100004 yields and time spectra. M078200100005 AUTHOR (V.Macary,E.Berthoumieux,D.Dore,S.Panebianco, M078200100006 D.Ridikas,J.-M.Laborie) M078200100007 INSTITUTE (2FR SAC,2FR BRC) CEA/DIF, Arpajon. M078200100008 REFERENCE (J,NT,168,287,2009) M078200100009 FACILITY (LINAC,2FR FR) Electron accelerator ELSA of CEA, M078200100010 Bruyeres-le-Chatel. M078200100011 INC-SOURCE (BRST) Electron beam with energy resolution of ~100 M078200100012 keV impinged on the 1.2 mm-thick Ta target. An Al M078200100013 cylinder stops the residual electrons. M078200100014 SAMPLE The 235U (237Np) target was a cylinder of 6.5 (8.05) M078200100015 cm diameter and of 0.02 (0.1) cm thickness for a M078200100016 weight of 12.5 (56.7) g. M078200100017 PART-DET (DN) M078200100018 METHOD (EXTB,SITA) M078200100019 DETECTOR (HE3SP) 12 3He gas counters surrounded by individual M078200100020 CH2 moderators. M078200100021 ANALYSIS (DECAY) Two different irradiation procedures were used M078200100022 in order to determine the DN absolute yield. M078200100023 The first one consists of a very short irradiation M078200100024 (T-irr << T-1/2) and long decay time (t >> T1/2). In M078200100025 this case absolute yield is proportional to the M078200100026 integral of the entire decay curve. The M078200100027 The second method is based on a very long irradiation M078200100028 (Tirr >> T1/2) and followed by a long decay time. In M078200100029 this case absolute yield is proportional to the time M078200100030 dependent yield. at the beginning of the decay. M078200100031 ERR-ANALYS (ERR-SYS) Systematical errors due to the uncertainty M078200100032 of the electron beam intensity and the detector M078200100033 efficiency are shown. M078200100034 Statistical uncertainties were negligible in cases of M078200100035 both nuclei. M078200100036 STATUS (CURVE) Data from the Fig. 3 have been compiled at the M078200100037 Russia MSU SINP CDFE by V.Varlamov. M078200100038 HISTORY (20100212C) M078200100039 ENDBIB 37 0 M078200100040 NOCOMMON 0 0 M078200100041 ENDSUBENT 40 0 M078200199999 SUBENT M0782002 20100212 M052M078200200001 BIB 1 3 M078200200002 REACTION (93-NP-237(G,F),DL,NU,,BRA) M078200200003 Absolute yield as a ratio of the emitted DN over M078200200004 number of fissions. M078200200005 ENDBIB 3 0 M078200200006 NOCOMMON 0 0 M078200200007 DATA 3 3 M078200200008 EN-MAX DATA ERR-SYS M078200200009 MEV PRT/FIS PRT/FIS M078200200010 15. .00456 .00079 M078200200011 16.6 .00598 .00075 M078200200012 18. .00549 .00068 M078200200013 ENDDATA 5 0 M078200200014 ENDSUBENT 13 0 M078200299999 SUBENT M0782003 20100212 M052M078200300001 BIB 1 1 M078200300002 REACTION (92-U-235(G,F),DL,NU,,BRA) M078200300003 ENDBIB 1 0 M078200300004 NOCOMMON 0 0 M078200300005 DATA 3 6 M078200300006 EN-MAX DATA ERR-SYS M078200300007 MEV PRT/FIS PRT/FIS M078200300008 12. .01099 .00135 M078200300009 13.5 .00915 .00138 M078200300010 15. .00733 .00122 M078200300011 16.5 .01078 .00127 M078200300012 18. .00993 .00123 M078200300013 18.5 .00855 .00125 M078200300014 ENDDATA 8 0 M078200300015 ENDSUBENT 14 0 M078200399999 ENDENTRY 3 0 M078299999999